Added PropertyName type

README-ru.md

@@ -425,7 +425,7 @@ View имеет ряд свойств, таких как высота, шири
 (View реализует данный интерфейс):
 
 	type Properties interface {
-		Get(tag string) any
+		Get(tag PropertyName) any
 		Set(tag string, value any) bool
 		Remove(tag string)
 		Clear()

README.md

@@ -429,7 +429,7 @@ View has a number of properties like height, width, color, text parameters, etc.
 The Properties interface is used to read and write the property value (View implements this interface):
 
 	type Properties interface {
-		Get(tag string) any
+		Get(tag PropertyName) any
 		Set(tag string, value any) bool
 		Remove(tag string)
 		Clear()

absoluteLayout.go

@@ -20,7 +20,8 @@ func NewAbsoluteLayout(session Session, params Params) AbsoluteLayout {
 }
 
 func newAbsoluteLayout(session Session) View {
-	return NewAbsoluteLayout(session, nil)
+	//return NewAbsoluteLayout(session, nil)
+	return new(absoluteLayoutData)
 }
 
 // Init initialize fields of ViewsContainer by default values

animation.go

@@ -18,7 +18,7 @@ const (
 	//
 	// Internal type is `[]Animation`, other types converted to it during assignment.
 	// See `Animation` description for more details.
-	AnimationTag = "animation"
+	AnimationTag PropertyName = "animation"
 
 	// AnimationPaused is the constant for "animation-paused" property tag.
 	//
@@ -30,7 +30,7 @@ const (
 	// Values:
 	// `true` or `1` or "true", "yes", "on", "1" - Animation is paused.
 	// `false` or `0` or "false", "no", "off", "0" - Animation is playing.
-	AnimationPaused = "animation-paused"
+	AnimationPaused PropertyName = "animation-paused"
 
 	// Transition is the constant for "transition" property tag.
 	//
@@ -44,7 +44,7 @@ const (
 	// Supported types: `Params`.
 	//
 	// See `Params` description for more details.
-	Transition = "transition"
+	Transition PropertyName = "transition"
 
 	// PropertyTag is the constant for "property" property tag.
 	//
@@ -55,7 +55,7 @@ const (
 	//
 	// Internal type is `[]AnimatedProperty`, other types converted to it during assignment.
 	// See `AnimatedProperty` description for more details.
-	PropertyTag = "property"
+	PropertyTag PropertyName = "property"
 
 	// Duration is the constant for "duration" property tag.
 	//
@@ -65,7 +65,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	Duration = "duration"
+	Duration PropertyName = "duration"
 
 	// Delay is the constant for "delay" property tag.
 	//
@@ -77,7 +77,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	Delay = "delay"
+	Delay PropertyName = "delay"
 
 	// TimingFunction is the constant for "timing-function" property tag.
 	//
@@ -92,7 +92,7 @@ const (
 	// "ease-out"(`EaseOutTiming`) - Speed is fast at first, but decreases in the end.
 	// "ease-in-out"(`EaseInOutTiming`) - Speed is slow at first, but quickly increases and at the end it decreases again.
 	// "linear"(`LinearTiming`) - Constant speed.
-	TimingFunction = "timing-function"
+	TimingFunction PropertyName = "timing-function"
 
 	// IterationCount is the constant for "iteration-count" property tag.
 	//
@@ -102,7 +102,7 @@ const (
 	// Supported types: `int`, `string`.
 	//
 	// Internal type is `int`, other types converted to it during assignment.
-	IterationCount = "iteration-count"
+	IterationCount PropertyName = "iteration-count"
 
 	// AnimationDirection is the constant for "animation-direction" property tag.
 	//
@@ -117,7 +117,7 @@ const (
 	// `1`(`ReverseAnimation`) or "reverse" - The animation plays backwards, from the last position to the first, and then resets to the final position and plays again.
 	// `2`(`AlternateAnimation`) or "alternate" - The animation changes direction in each cycle, that is, in the first cycle, it starts from the start position, reaches the end position, and in the second cycle, it continues from the end position and reaches the start position, and so on.
 	// `3`(`AlternateReverseAnimation`) or "alternate-reverse" - The animation starts playing from the end position and reaches the start position, and in the next cycle, continuing from the start position, it goes to the end position.
-	AnimationDirection = "animation-direction"
+	AnimationDirection PropertyName = "animation-direction"
 
 	// NormalAnimation is value of the "animation-direction" property.
 	// The animation plays forwards each cycle. In other words, each time the animation cycles,
@@ -180,7 +180,7 @@ func CubicBezierTiming(x1, y1, x2, y2 float64) string {
 // AnimatedProperty describes the change script of one property
 type AnimatedProperty struct {
 	// Tag is the name of the property
-	Tag string
+	Tag PropertyName
 	// From is the initial value of the property
 	From any
 	// To is the final value of the property
@@ -190,12 +190,12 @@ type AnimatedProperty struct {
 }
 
 type animationData struct {
-	propertyList
+	dataProperty
 	keyFramesName string
 	usageCounter  int
 	view          View
-	listener      func(view View, animation Animation, event string)
+	listener      func(view View, animation Animation, event PropertyName)
-	oldListeners  map[string][]func(View, string)
+	oldListeners  map[PropertyName][]func(View, PropertyName)
 	oldAnimation  []Animation
 }
 
@@ -207,7 +207,7 @@ type Animation interface {
 
 	// Start starts the animation for the view specified by the first argument.
 	// The second argument specifies the animation event listener (can be nil)
-	Start(view View, listener func(view View, animation Animation, event string)) bool
+	Start(view View, listener func(view View, animation Animation, event PropertyName)) bool
 	// Stop stops the animation
 	Stop()
 	// Pause pauses the animation
@@ -215,7 +215,7 @@ type Animation interface {
 	// Resume resumes an animation that was stopped using the Pause method
 	Resume()
 
-	writeTransitionString(tag string, buffer *strings.Builder)
+	writeTransitionString(tag PropertyName, buffer *strings.Builder)
 	animationCSS(session Session) string
 	transitionCSS(buffer *strings.Builder, session Session)
 	hasAnimatedProperty() bool
@@ -230,10 +230,11 @@ func parseAnimation(obj DataObject) Animation {
 
 	for i := 0; i < obj.PropertyCount(); i++ {
 		if node := obj.Property(i); node != nil {
+			tag := PropertyName(node.Tag())
 			if node.Type() == TextNode {
-				animation.Set(node.Tag(), node.Text())
+				animation.Set(tag, node.Text())
 			} else {
-				animation.Set(node.Tag(), node)
+				animation.Set(tag, node)
 			}
 		}
 	}
@@ -251,6 +252,13 @@ func NewAnimation(params Params) Animation {
 	return animation
 }
 
+func (animation *animationData) init() {
+	animation.dataProperty.init()
+	animation.normalize = normalizeAnimationTag
+	animation.set = animationSet
+	animation.supportedProperties = []PropertyName{ID, PropertyTag, Duration, Delay, TimingFunction, IterationCount, AnimationDirection}
+}
+
 func (animation *animationData) animatedProperties() []AnimatedProperty {
 	value := animation.getRaw(PropertyTag)
 	if value == nil {
@@ -291,33 +299,28 @@ func (animation *animationData) unused(session Session) {
 	}
 }
 
-func (animation *animationData) normalizeTag(tag string) string {
+func normalizeAnimationTag(tag PropertyName) PropertyName {
-	tag = strings.ToLower(tag)
+	tag = defaultNormalize(tag)
 	if tag == Direction {
 		return AnimationDirection
 	}
 	return tag
 }
 
-func (animation *animationData) Set(tag string, value any) bool {
+func animationSet(properties Properties, tag PropertyName, value any) []PropertyName {
-	if value == nil {
+	switch tag {
-		animation.Remove(tag)
-		return true
-	}
-
-	switch tag = animation.normalizeTag(tag); tag {
 	case ID:
 		if text, ok := value.(string); ok {
 			text = strings.Trim(text, " \t\n\r")
 			if text == "" {
-				delete(animation.properties, tag)
+				properties.setRaw(tag, nil)
 			} else {
-				animation.properties[tag] = text
+				properties.setRaw(tag, text)
 			}
-			return true
+			return []PropertyName{tag}
 		}
 		notCompatibleType(tag, value)
-		return false
+		return nil
 
 	case PropertyTag:
 		switch value := value.(type) {
@@ -340,8 +343,8 @@ func (animation *animationData) Set(tag string, value any) bool {
 			} else if value.To == nil {
 				ErrorLog("AnimatedProperty.To is nil")
 			} else {
-				animation.properties[tag] = []AnimatedProperty{value}
+				properties.setRaw(tag, []AnimatedProperty{value})
-				return true
+				return []PropertyName{tag}
 			}
 
 		case []AnimatedProperty:
@@ -369,8 +372,8 @@ func (animation *animationData) Set(tag string, value any) bool {
 				}
 			}
 			if len(props) > 0 {
-				animation.properties[tag] = props
+				properties.setRaw(tag, props)
-				return true
+				return []PropertyName{tag}
 			} else {
 				ErrorLog("[]AnimatedProperty is empty")
 			}
@@ -417,8 +420,8 @@ func (animation *animationData) Set(tag string, value any) bool {
 			switch value.Type() {
 			case ObjectNode:
 				if prop, ok := parseObject(value.Object()); ok {
-					animation.properties[tag] = []AnimatedProperty{prop}
+					properties.setRaw(tag, []AnimatedProperty{prop})
-					return true
+					return []PropertyName{tag}
 				}
 
 			case ArrayNode:
@@ -433,8 +436,8 @@ func (animation *animationData) Set(tag string, value any) bool {
 					}
 				}
 				if len(props) > 0 {
-					animation.properties[tag] = props
+					properties.setRaw(tag, props)
-					return true
+					return []PropertyName{tag}
 				}
 
 			default:
@@ -446,36 +449,28 @@ func (animation *animationData) Set(tag string, value any) bool {
 		}
 
 	case Duration:
-		return animation.setFloatProperty(tag, value, 0, math.MaxFloat64)
+		return setFloatProperty(properties, tag, value, 0, math.MaxFloat64)
 
 	case Delay:
-		return animation.setFloatProperty(tag, value, -math.MaxFloat64, math.MaxFloat64)
+		return setFloatProperty(properties, tag, value, -math.MaxFloat64, math.MaxFloat64)
 
 	case TimingFunction:
 		if text, ok := value.(string); ok {
-			animation.properties[tag] = text
+			properties.setRaw(tag, text)
-			return true
+			return []PropertyName{tag}
 		}
 
 	case IterationCount:
-		return animation.setIntProperty(tag, value)
+		return setIntProperty(properties, tag, value)
 
 	case AnimationDirection:
-		return animation.setEnumProperty(AnimationDirection, value, enumProperties[AnimationDirection].values)
+		return setEnumProperty(properties, AnimationDirection, value, enumProperties[AnimationDirection].values)
 
 	default:
 		ErrorLogF(`The "%s" property is not supported by Animation`, tag)
 	}
 
-	return false
+	return nil
-}
-
-func (animation *animationData) Remove(tag string) {
-	delete(animation.properties, animation.normalizeTag(tag))
-}
-
-func (animation *animationData) Get(tag string) any {
-	return animation.getRaw(animation.normalizeTag(tag))
 }
 
 func (animation *animationData) String() string {
@@ -488,7 +483,7 @@ func (animation *animationData) String() string {
 		if tag != PropertyTag {
 			if value, ok := animation.properties[tag]; ok && value != nil {
 				buffer.WriteString("\n\t")
-				buffer.WriteString(tag)
+				buffer.WriteString(string(tag))
 				buffer.WriteString(" = ")
 				writePropertyValue(buffer, tag, value, "\t")
 				buffer.WriteRune(',')
@@ -497,7 +492,7 @@ func (animation *animationData) String() string {
 	}
 
 	writeProperty := func(prop AnimatedProperty, indent string) {
-		buffer.WriteString(prop.Tag)
+		buffer.WriteString(string(prop.Tag))
 		buffer.WriteString("{\n")
 		buffer.WriteString(indent)
 		buffer.WriteString("from = ")
@@ -512,7 +507,7 @@ func (animation *animationData) String() string {
 			tag := strconv.Itoa(key) + "%"
 			buffer.WriteString(tag)
 			buffer.WriteString(" = ")
-			writePropertyValue(buffer, tag, value, indent)
+			writePropertyValue(buffer, PropertyName(tag), value, indent)
 		}
 		buffer.WriteString("\n")
 		buffer.WriteString(indent[1:])
@@ -522,7 +517,7 @@ func (animation *animationData) String() string {
 	if props := animation.animatedProperties(); len(props) > 0 {
 
 		buffer.WriteString("\n\t")
-		buffer.WriteString(PropertyTag)
+		buffer.WriteString(string(PropertyTag))
 		buffer.WriteString(" = ")
 		if len(props) > 1 {
 			buffer.WriteString("[\n")
@@ -606,15 +601,15 @@ func (animation *animationData) transitionCSS(buffer *strings.Builder, session S
 	}
 }
 
-func (animation *animationData) writeTransitionString(tag string, buffer *strings.Builder) {
+func (animation *animationData) writeTransitionString(tag PropertyName, buffer *strings.Builder) {
-	buffer.WriteString(tag)
+	buffer.WriteString(string(tag))
 	buffer.WriteString("{")
 	lead := " "
 
-	writeFloatProperty := func(name string) bool {
+	writeFloatProperty := func(name PropertyName) bool {
 		if value := animation.getRaw(name); value != nil {
 			buffer.WriteString(lead)
-			buffer.WriteString(name)
+			buffer.WriteString(string(name))
 			buffer.WriteString(" = ")
 			writePropertyValue(buffer, name, value, "")
 			lead = ", "
@@ -633,7 +628,7 @@ func (animation *animationData) writeTransitionString(tag string, buffer *string
 	if value := animation.getRaw(TimingFunction); value != nil {
 		if timingFunction, ok := value.(string); ok && timingFunction != "" {
 			buffer.WriteString(lead)
-			buffer.WriteString(TimingFunction)
+			buffer.WriteString(string(TimingFunction))
 			buffer.WriteString(" = ")
 			if strings.ContainsAny(timingFunction, " ,()") {
 				buffer.WriteRune('"')
@@ -767,7 +762,7 @@ func (session *sessionData) registerAnimation(props []AnimatedProperty) string {
 	return name
 }
 
-func (view *viewData) SetAnimated(tag string, value any, animation Animation) bool {
+func (view *viewData) SetAnimated(tag PropertyName, value any, animation Animation) bool {
 	if animation == nil {
 		return view.Set(tag, value)
 	}
@@ -779,27 +774,30 @@ func (view *viewData) SetAnimated(tag string, value any, animation Animation) bo
 	session.updateProperty(htmlID, "ontransitionend", "transitionEndEvent(this, event)")
 	session.updateProperty(htmlID, "ontransitioncancel", "transitionCancelEvent(this, event)")
 
-	if prevAnimation, ok := view.transitions[tag]; ok {
+	transitions := getTransitionProperty(view)
-		view.singleTransition[tag] = prevAnimation
+	var prevAnimation Animation = nil
-	} else {
+	if transitions != nil {
-		view.singleTransition[tag] = nil
+		if prev, ok := transitions[tag]; ok {
+			prevAnimation = prev
 		}
-	view.transitions[tag] = animation
+	}
-	view.updateTransitionCSS()
+	view.singleTransition[tag] = prevAnimation
+	setTransition(view, tag, animation)
+	view.session.updateCSSProperty(view.htmlID(), "transition", transitionCSS(view, view.session))
 
 	session.finishUpdateScript(htmlID)
 
 	result := view.Set(tag, value)
 	if !result {
 		delete(view.singleTransition, tag)
-		view.updateTransitionCSS()
+		view.session.updateCSSProperty(view.htmlID(), "transition", transitionCSS(view, view.session))
 	}
 
 	return result
 }
 
-func (style *viewStyle) animationCSS(session Session) string {
+func animationCSS(properties Properties, session Session) string {
-	if value := style.getRaw(AnimationTag); value != nil {
+	if value := properties.getRaw(AnimationTag); value != nil {
 		if animations, ok := value.([]Animation); ok {
 			buffer := allocStringBuilder()
 			defer freeStringBuilder(buffer)
@@ -820,11 +818,12 @@ func (style *viewStyle) animationCSS(session Session) string {
 	return ""
 }
 
-func (style *viewStyle) transitionCSS(session Session) string {
+func transitionCSS(properties Properties, session Session) string {
+	if transitions := getTransitionProperty(properties); len(transitions) > 0 {
 		buffer := allocStringBuilder()
 		defer freeStringBuilder(buffer)
 
-	convert := map[string]string{
+		convert := map[PropertyName]string{
 			CellHeight:        "grid-template-rows",
 			CellWidth:         "grid-template-columns",
 			Row:               "grid-row",
@@ -837,7 +836,7 @@ func (style *viewStyle) transitionCSS(session Session) string {
 			TextLineThickness: "text-decoration-thickness",
 		}
 
-	for tag, animation := range style.transitions {
+		for tag, animation := range transitions {
 			if buffer.Len() > 0 {
 				buffer.WriteString(", ")
 			}
@@ -845,53 +844,128 @@ func (style *viewStyle) transitionCSS(session Session) string {
 			if cssTag, ok := convert[tag]; ok {
 				buffer.WriteString(cssTag)
 			} else {
-			buffer.WriteString(tag)
+				buffer.WriteString(string(tag))
 			}
 			animation.transitionCSS(buffer, session)
 		}
 		return buffer.String()
 	}
-
+	return ""
-func (view *viewData) updateTransitionCSS() {
-	view.session.updateCSSProperty(view.htmlID(), "transition", view.transitionCSS(view.session))
 }
 
-func (style *viewStyle) Transition(tag string) Animation {
+/*
-	if style.transitions != nil {
+func (view *viewData) updateTransitionCSS() {
-		if anim, ok := style.transitions[tag]; ok {
+	view.session.updateCSSProperty(view.htmlID(), "transition", transitionCSS(view, view.session))
+}
+*/
+
+func (style *viewStyle) Transition(tag PropertyName) Animation {
+	if transitions := getTransitionProperty(style); transitions != nil {
+		if anim, ok := transitions[tag]; ok {
 			return anim
 		}
 	}
 	return nil
 }
 
-func (style *viewStyle) Transitions() map[string]Animation {
+func (style *viewStyle) Transitions() map[PropertyName]Animation {
-	result := map[string]Animation{}
+	result := map[PropertyName]Animation{}
-	for tag, animation := range style.transitions {
+	for tag, animation := range getTransitionProperty(style) {
 		result[tag] = animation
 	}
 	return result
 }
 
-func (style *viewStyle) SetTransition(tag string, animation Animation) {
+func (style *viewStyle) SetTransition(tag PropertyName, animation Animation) {
-	if animation == nil {
+	setTransition(style, style.normalize(tag), animation)
-		delete(style.transitions, tag)
+}
-	} else {
+
-		style.transitions[tag] = animation
+func (view *viewData) SetTransition(tag PropertyName, animation Animation) {
+	setTransition(view, view.normalize(tag), animation)
+	if view.created {
+		view.session.updateCSSProperty(view.htmlID(), "transition", transitionCSS(view, view.session))
 	}
 }
 
-func (view *viewData) SetTransition(tag string, animation Animation) {
+func setTransition(properties Properties, tag PropertyName, animation Animation) {
-	view.viewStyle.SetTransition(tag, animation)
+	transitions := getTransitionProperty(properties)
-	if view.created {
+
-		view.session.updateCSSProperty(view.htmlID(), "transition", view.transitionCSS(view.session))
+	if animation == nil {
+		if transitions != nil {
+			delete(transitions, tag)
+			if len(transitions) == 0 {
+				properties.setRaw(Transition, nil)
 			}
 		}
+	} else if transitions != nil {
+		transitions[tag] = animation
+	} else {
+		properties.setRaw(Transition, map[PropertyName]Animation{tag: animation})
+	}
+}
+
+func getTransitionProperty(properties Properties) map[PropertyName]Animation {
+	if value := properties.getRaw(Transition); value != nil {
+		if transitions, ok := value.(map[PropertyName]Animation); ok {
+			return transitions
+		}
+	}
+	return nil
+}
+
+func setAnimationProperty(properties Properties, tag PropertyName, value any) bool {
+
+	set := func(animations []Animation) {
+		properties.setRaw(tag, animations)
+		for _, animation := range animations {
+			animation.used()
+		}
+	}
+
+	switch value := value.(type) {
+	case Animation:
+		set([]Animation{value})
+		return true
+
+	case []Animation:
+		set(value)
+		return true
+
+	case DataObject:
+		if animation := parseAnimation(value); animation.hasAnimatedProperty() {
+			set([]Animation{animation})
+			return true
+		}
+
+	case DataNode:
+		animations := []Animation{}
+		result := true
+		for i := 0; i < value.ArraySize(); i++ {
+			if obj := value.ArrayElement(i).Object(); obj != nil {
+				if anim := parseAnimation(obj); anim.hasAnimatedProperty() {
+					animations = append(animations, anim)
+				} else {
+					result = false
+				}
+			} else {
+				notCompatibleType(tag, value.ArrayElement(i))
+				result = false
+			}
+		}
+		if result && len(animations) > 0 {
+			set(animations)
+		}
+		return result
+	}
+
+	notCompatibleType(tag, value)
+	return false
+}
 
 // SetAnimated sets the property with name "tag" of the "rootView" subview with "viewID" id by value. Result:
 // true - success,
 // false - error (incompatible type or invalid format of a string value, see AppLog).
-func SetAnimated(rootView View, viewID, tag string, value any, animation Animation) bool {
+func SetAnimated(rootView View, viewID string, tag PropertyName, value any, animation Animation) bool {
 	if view := ViewByID(rootView, viewID); view != nil {
 		return view.SetAnimated(tag, value, animation)
 	}
@@ -906,7 +980,7 @@ func IsAnimationPaused(view View, subviewID ...string) bool {
 
 // GetTransitions returns the subview transitions. The result is always non-nil.
 // If the second argument (subviewID) is not specified or it is "" then transitions of the first argument (view) is returned
-func GetTransitions(view View, subviewID ...string) map[string]Animation {
+func GetTransitions(view View, subviewID ...string) map[PropertyName]Animation {
 	if len(subviewID) > 0 && subviewID[0] != "" {
 		view = ViewByID(view, subviewID[0])
 	}
@@ -915,12 +989,12 @@ func GetTransitions(view View, subviewID ...string) map[string]Animation {
 		return view.Transitions()
 	}
 
-	return map[string]Animation{}
+	return map[PropertyName]Animation{}
 }
 
 // GetTransition returns the subview property transition. If there is no transition for the given property then nil is returned.
 // If the second argument (subviewID) is not specified or it is "" then transitions of the first argument (view) is returned
-func GetTransition(view View, subviewID, tag string) Animation {
+func GetTransition(view View, subviewID string, tag PropertyName) Animation {
 	if subviewID != "" {
 		view = ViewByID(view, subviewID)
 	}
@@ -934,7 +1008,7 @@ func GetTransition(view View, subviewID, tag string) Animation {
 
 // AddTransition adds the transition for the subview property.
 // If the second argument (subviewID) is not specified or it is "" then the transition is added to the first argument (view)
-func AddTransition(view View, subviewID, tag string, animation Animation) bool {
+func AddTransition(view View, subviewID string, tag PropertyName, animation Animation) bool {
 	if tag != "" {
 		if subviewID != "" {
 			view = ViewByID(view, subviewID)

animationEvents.go

@@ -1,7 +1,5 @@
 package rui
 
-import "strings"
-
 // Constants which describe values for view's animation events properties
 const (
 	// TransitionRunEvent is the constant for "transition-run-event" property tag.
@@ -20,7 +18,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(propertyName string)`,
 	// `func()`.
-	TransitionRunEvent = "transition-run-event"
+	TransitionRunEvent PropertyName = "transition-run-event"
 
 	// TransitionStartEvent is the constant for "transition-start-event" property tag.
 	//
@@ -38,7 +36,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(propertyName string)`,
 	// `func()`.
-	TransitionStartEvent = "transition-start-event"
+	TransitionStartEvent PropertyName = "transition-start-event"
 
 	// TransitionEndEvent is the constant for "transition-end-event" property tag.
 	//
@@ -56,7 +54,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(propertyName string)`,
 	// `func()`.
-	TransitionEndEvent = "transition-end-event"
+	TransitionEndEvent PropertyName = "transition-end-event"
 
 	// TransitionCancelEvent is the constant for "transition-cancel-event" property tag.
 	//
@@ -76,7 +74,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(propertyName string)`,
 	// `func()`.
-	TransitionCancelEvent = "transition-cancel-event"
+	TransitionCancelEvent PropertyName = "transition-cancel-event"
 
 	// AnimationStartEvent is the constant for "animation-start-event" property tag.
 	//
@@ -95,7 +93,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(animationId string)`,
 	// `func()`.
-	AnimationStartEvent = "animation-start-event"
+	AnimationStartEvent PropertyName = "animation-start-event"
 
 	// AnimationEndEvent is the constant for "animation-end-event" property tag.
 	//
@@ -114,7 +112,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(animationId string)`,
 	// `func()`.
-	AnimationEndEvent = "animation-end-event"
+	AnimationEndEvent PropertyName = "animation-end-event"
 
 	// AnimationCancelEvent is the constant for "animation-cancel-event" property tag.
 	//
@@ -135,7 +133,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(animationId string)`,
 	// `func()`.
-	AnimationCancelEvent = "animation-cancel-event"
+	AnimationCancelEvent PropertyName = "animation-cancel-event"
 
 	// AnimationIterationEvent is the constant for "animation-iteration-event" property tag.
 	//
@@ -154,48 +152,36 @@ const (
 	// `func(view rui.View)`,
 	// `func(animationId string)`,
 	// `func()`.
-	AnimationIterationEvent = "animation-iteration-event"
+	AnimationIterationEvent PropertyName = "animation-iteration-event"
 )
 
-var transitionEvents = map[string]struct{ jsEvent, jsFunc string }{
+/*
-	TransitionRunEvent:    {jsEvent: "ontransitionrun", jsFunc: "transitionRunEvent"},
+func setTransitionListener(properties Properties, tag PropertyName, value any) bool {
-	TransitionStartEvent:  {jsEvent: "ontransitionstart", jsFunc: "transitionStartEvent"},
+	if listeners, ok := valueToEventListeners[View, string](value); ok {
-	TransitionEndEvent:    {jsEvent: "ontransitionend", jsFunc: "transitionEndEvent"},
+		if len(listeners) == 0 {
-	TransitionCancelEvent: {jsEvent: "ontransitioncancel", jsFunc: "transitionCancelEvent"},
+			properties.setRaw(tag, nil)
+		} else {
+			properties.setRaw(tag, listeners)
+		}
+		return true
 	}
-
-func (view *viewData) setTransitionListener(tag string, value any) bool {
-	listeners, ok := valueToEventListeners[View, string](value)
-	if !ok {
 	notCompatibleType(tag, value)
 	return false
 }
 
-	if listeners == nil {
+func (view *viewData) removeTransitionListener(tag PropertyName) {
-		view.removeTransitionListener(tag)
-	} else if js, ok := transitionEvents[tag]; ok {
-		view.properties[tag] = listeners
-		if view.created {
-			view.session.updateProperty(view.htmlID(), js.jsEvent, js.jsFunc+"(this, event)")
-		}
-	} else {
-		return false
-	}
-	return true
-}
-
-func (view *viewData) removeTransitionListener(tag string) {
 	delete(view.properties, tag)
 	if view.created {
-		if js, ok := transitionEvents[tag]; ok {
+		if js, ok := eventJsFunc[tag]; ok {
 			view.session.removeProperty(view.htmlID(), js.jsEvent)
 		}
 	}
 }
 
 func transitionEventsHtml(view View, buffer *strings.Builder) {
-	for tag, js := range transitionEvents {
+	for _, tag := range []PropertyName{TransitionRunEvent, TransitionStartEvent, TransitionEndEvent, TransitionCancelEvent} {
 		if value := view.getRaw(tag); value != nil {
+			if js, ok := eventJsFunc[tag]; ok {
 				if listeners, ok := value.([]func(View, string)); ok && len(listeners) > 0 {
 					buffer.WriteString(js.jsEvent)
 					buffer.WriteString(`="`)
@@ -205,67 +191,55 @@ func transitionEventsHtml(view View, buffer *strings.Builder) {
 			}
 		}
 	}
+}
+*/
 
-func (view *viewData) handleTransitionEvents(tag string, data DataObject) {
+func (view *viewData) handleTransitionEvents(tag PropertyName, data DataObject) {
-	if property, ok := data.PropertyValue("property"); ok {
+	if propertyName, ok := data.PropertyValue("property"); ok {
+		property := PropertyName(propertyName)
 		if tag == TransitionEndEvent || tag == TransitionCancelEvent {
 			if animation, ok := view.singleTransition[property]; ok {
 				delete(view.singleTransition, property)
-				if animation != nil {
+				setTransition(view, tag, animation)
-					view.transitions[property] = animation
+				session := view.session
-				} else {
+				session.updateCSSProperty(view.htmlID(), "transition", transitionCSS(view, session))
-					delete(view.transitions, property)
-				}
-				view.updateTransitionCSS()
 			}
 		}
 
-		for _, listener := range getEventListeners[View, string](view, nil, tag) {
+		for _, listener := range getEventListeners[View, PropertyName](view, nil, tag) {
 			listener(view, property)
 		}
 	}
 }
 
-var animationEvents = map[string]struct{ jsEvent, jsFunc string }{
+/*
-	AnimationStartEvent:     {jsEvent: "onanimationstart", jsFunc: "animationStartEvent"},
+	func setAnimationListener(properties Properties, tag PropertyName, value any) bool {
-	AnimationEndEvent:       {jsEvent: "onanimationend", jsFunc: "animationEndEvent"},
+		if listeners, ok := valueToEventListeners[View, string](value); ok {
-	AnimationIterationEvent: {jsEvent: "onanimationiteration", jsFunc: "animationIterationEvent"},
+			if len(listeners) == 0 {
-	AnimationCancelEvent:    {jsEvent: "onanimationcancel", jsFunc: "animationCancelEvent"},
+				properties.setRaw(tag, nil)
+			} else {
+				properties.setRaw(tag, listeners)
+			}
+			return true
 		}
-
-func (view *viewData) setAnimationListener(tag string, value any) bool {
-	listeners, ok := valueToEventListeners[View, string](value)
-	if !ok {
 		notCompatibleType(tag, value)
 		return false
 	}
 
-	if listeners == nil {
+func (view *viewData) removeAnimationListener(tag PropertyName) {
-		view.removeAnimationListener(tag)
-	} else if js, ok := animationEvents[tag]; ok {
-		view.properties[tag] = listeners
-		if view.created {
-			view.session.updateProperty(view.htmlID(), js.jsEvent, js.jsFunc+"(this, event)")
-		}
-	} else {
-		return false
-	}
-	return true
-}
-
-func (view *viewData) removeAnimationListener(tag string) {
 	delete(view.properties, tag)
 	if view.created {
-		if js, ok := animationEvents[tag]; ok {
+		if js, ok := eventJsFunc[tag]; ok {
 			view.session.removeProperty(view.htmlID(), js.jsEvent)
 		}
 	}
 }
 
 func animationEventsHtml(view View, buffer *strings.Builder) {
-	for tag, js := range animationEvents {
+	for _, tag := range []PropertyName{AnimationStartEvent, AnimationEndEvent, AnimationIterationEvent, AnimationCancelEvent} {
 		if value := view.getRaw(tag); value != nil {
-			if listeners, ok := value.([]func(View)); ok && len(listeners) > 0 {
+			if js, ok := eventJsFunc[tag]; ok {
+				if listeners, ok := value.([]func(View, string)); ok && len(listeners) > 0 {
 					buffer.WriteString(js.jsEvent)
 					buffer.WriteString(`="`)
 					buffer.WriteString(js.jsFunc)
@@ -274,8 +248,10 @@ func animationEventsHtml(view View, buffer *strings.Builder) {
 			}
 		}
 	}
+}
+*/
 
-func (view *viewData) handleAnimationEvents(tag string, data DataObject) {
+func (view *viewData) handleAnimationEvents(tag PropertyName, data DataObject) {
 	if listeners := getEventListeners[View, string](view, nil, tag); len(listeners) > 0 {
 		id := ""
 		if name, ok := data.PropertyValue("name"); ok {

animationRun.go

@@ -1,6 +1,6 @@
 package rui
 
-func (animation *animationData) Start(view View, listener func(view View, animation Animation, event string)) bool {
+func (animation *animationData) Start(view View, listener func(view View, animation Animation, event PropertyName)) bool {
 	if view == nil {
 		ErrorLog("nil View in animation.Start() function")
 		return false
@@ -19,12 +19,12 @@ func (animation *animationData) Start(view View, listener func(view View, animat
 		}
 	}
 
-	animation.oldListeners = map[string][]func(View, string){}
+	animation.oldListeners = map[PropertyName][]func(View, PropertyName){}
 
-	setListeners := func(event string, listener func(View, string)) {
+	setListeners := func(event PropertyName, listener func(View, PropertyName)) {
-		var listeners []func(View, string) = nil
+		var listeners []func(View, PropertyName) = nil
 		if value := view.Get(event); value != nil {
-			if oldListeners, ok := value.([]func(View, string)); ok && len(oldListeners) > 0 {
+			if oldListeners, ok := value.([]func(View, PropertyName)); ok && len(oldListeners) > 0 {
 				listeners = oldListeners
 			}
 		}
@@ -48,7 +48,7 @@ func (animation *animationData) Start(view View, listener func(view View, animat
 
 func (animation *animationData) finish() {
 	if animation.view != nil {
-		for _, event := range []string{AnimationStartEvent, AnimationEndEvent, AnimationCancelEvent, AnimationIterationEvent} {
+		for _, event := range []PropertyName{AnimationStartEvent, AnimationEndEvent, AnimationCancelEvent, AnimationIterationEvent} {
 			if listeners, ok := animation.oldListeners[event]; ok {
 				animation.view.Set(event, listeners)
 			} else {
@@ -63,7 +63,7 @@ func (animation *animationData) finish() {
 			animation.view.Set(AnimationTag, "")
 		}
 
-		animation.oldListeners = map[string][]func(View, string){}
+		animation.oldListeners = map[PropertyName][]func(View, PropertyName){}
 
 		animation.view = nil
 		animation.listener = nil
@@ -86,13 +86,13 @@ func (animation *animationData) Resume() {
 	}
 }
 
-func (animation *animationData) onAnimationStart(view View, _ string) {
+func (animation *animationData) onAnimationStart(view View, _ PropertyName) {
 	if animation.view != nil && animation.listener != nil {
 		animation.listener(animation.view, animation, AnimationStartEvent)
 	}
 }
 
-func (animation *animationData) onAnimationEnd(view View, _ string) {
+func (animation *animationData) onAnimationEnd(view View, _ PropertyName) {
 	if animation.view != nil {
 		animationView := animation.view
 		listener := animation.listener
@@ -112,13 +112,13 @@ func (animation *animationData) onAnimationEnd(view View, _ string) {
 	}
 }
 
-func (animation *animationData) onAnimationIteration(view View, _ string) {
+func (animation *animationData) onAnimationIteration(view View, _ PropertyName) {
 	if animation.view != nil && animation.listener != nil {
 		animation.listener(animation.view, animation, AnimationIterationEvent)
 	}
 }
 
-func (animation *animationData) onAnimationCancel(view View, _ string) {
+func (animation *animationData) onAnimationCancel(view View, _ PropertyName) {
 	if animation.view != nil {
 		animationView := animation.view
 		listener := animation.listener

app_scripts.js

@@ -215,6 +215,14 @@ function appendToInnerHTML(elementId, content) {
 	}
 }
 
+function appendToInputValue(elementId, content) {
+	const element = document.getElementById(elementId);
+	if (element) {
+		element.value += content;
+		scanElementsSize();
+	}
+}
+
 function setDisabled(elementId, disabled) {
 	const element = document.getElementById(elementId);
 	if (element) {

audioPlayer.go

@@ -13,13 +13,12 @@ type audioPlayerData struct {
 func NewAudioPlayer(session Session, params Params) AudioPlayer {
 	view := new(audioPlayerData)
 	view.init(session)
-	view.tag = "AudioPlayer"
 	setInitParams(view, params)
 	return view
 }
 
 func newAudioPlayer(session Session) View {
-	return NewAudioPlayer(session, nil)
+	return new(audioPlayerData) // NewAudioPlayer(session, nil)
 }
 
 func (player *audioPlayerData) init(session Session) {
@@ -27,10 +26,6 @@ func (player *audioPlayerData) init(session Session) {
 	player.tag = "AudioPlayer"
 }
 
-func (player *audioPlayerData) String() string {
-	return getViewString(player, nil)
-}
-
 func (player *audioPlayerData) htmlTag() string {
 	return "audio"
 }

background.go

@@ -78,7 +78,7 @@ type BackgroundElement interface {
 }
 
 type backgroundElement struct {
-	propertyList
+	dataProperty
 }
 
 type backgroundImage struct {
@@ -91,24 +91,16 @@ func createBackground(obj DataObject) BackgroundElement {
 
 	switch obj.Tag() {
 	case "image":
-		image := new(backgroundImage)
+		result = NewBackgroundImage(nil)
-		image.properties = map[string]any{}
-		result = image
 
 	case "linear-gradient":
-		gradient := new(backgroundLinearGradient)
+		result = NewBackgroundLinearGradient(nil)
-		gradient.properties = map[string]any{}
-		result = gradient
 
 	case "radial-gradient":
-		gradient := new(backgroundRadialGradient)
+		result = NewBackgroundRadialGradient(nil)
-		gradient.properties = map[string]any{}
-		result = gradient
 
 	case "conic-gradient":
-		gradient := new(backgroundConicGradient)
+		result = NewBackgroundConicGradient(nil)
-		gradient.properties = map[string]any{}
-		result = gradient
 
 	default:
 		return nil
@@ -118,7 +110,7 @@ func createBackground(obj DataObject) BackgroundElement {
 	for i := 0; i < count; i++ {
 		if node := obj.Property(i); node.Type() == TextNode {
 			if value := node.Text(); value != "" {
-				result.Set(node.Tag(), value)
+				result.Set(PropertyName(node.Tag()), value)
 			}
 		}
 	}
@@ -129,13 +121,21 @@ func createBackground(obj DataObject) BackgroundElement {
 // NewBackgroundImage creates the new background image
 func NewBackgroundImage(params Params) BackgroundElement {
 	result := new(backgroundImage)
-	result.properties = map[string]any{}
+	result.init()
 	for tag, value := range params {
 		result.Set(tag, value)
 	}
 	return result
 }
 
+func (image *backgroundImage) init() {
+	image.backgroundElement.init()
+	image.normalize = normalizeBackgroundImageTag
+	image.supportedProperties = []PropertyName{
+		Attachment, Width, Height, Repeat, ImageHorizontalAlign, ImageVerticalAlign, backgroundFit, Source,
+	}
+}
+
 func (image *backgroundImage) Tag() string {
 	return "image"
 }
@@ -148,8 +148,8 @@ func (image *backgroundImage) Clone() BackgroundElement {
 	return result
 }
 
-func (image *backgroundImage) normalizeTag(tag string) string {
+func normalizeBackgroundImageTag(tag PropertyName) PropertyName {
-	tag = strings.ToLower(tag)
+	tag = defaultNormalize(tag)
 	switch tag {
 	case "source":
 		tag = Source
@@ -167,21 +167,6 @@ func (image *backgroundImage) normalizeTag(tag string) string {
 	return tag
 }
 
-func (image *backgroundImage) Set(tag string, value any) bool {
-	tag = image.normalizeTag(tag)
-	switch tag {
-	case Attachment, Width, Height, Repeat, ImageHorizontalAlign, ImageVerticalAlign,
-		backgroundFit, Source:
-		return image.backgroundElement.Set(tag, value)
-	}
-
-	return false
-}
-
-func (image *backgroundImage) Get(tag string) any {
-	return image.backgroundElement.Get(image.normalizeTag(tag))
-}
-
 func (image *backgroundImage) cssStyle(session Session) string {
 	if src, ok := imageProperty(image, Source, session); ok && src != "" {
 		buffer := allocStringBuilder()
@@ -252,7 +237,7 @@ func (image *backgroundImage) cssStyle(session Session) string {
 }
 
 func (image *backgroundImage) writeString(buffer *strings.Builder, indent string) {
-	image.writeToBuffer(buffer, indent, image.Tag(), []string{
+	image.writeToBuffer(buffer, indent, image.Tag(), []PropertyName{
 		Source,
 		Width,
 		Height,
@@ -267,3 +252,76 @@ func (image *backgroundImage) writeString(buffer *strings.Builder, indent string
 func (image *backgroundImage) String() string {
 	return runStringWriter(image)
 }
+
+func setBackgroundProperty(properties Properties, value any) []PropertyName {
+	background := []BackgroundElement{}
+
+	error := func() []PropertyName {
+		notCompatibleType(Background, value)
+		return nil
+	}
+
+	switch value := value.(type) {
+	case BackgroundElement:
+		background = []BackgroundElement{value}
+
+	case []BackgroundElement:
+		background = value
+
+	case []DataValue:
+		for _, el := range value {
+			if el.IsObject() {
+				if element := createBackground(el.Object()); element != nil {
+					background = append(background, element)
+				} else {
+					return error()
+				}
+			} else if obj := ParseDataText(el.Value()); obj != nil {
+				if element := createBackground(obj); element != nil {
+					background = append(background, element)
+				} else {
+					return error()
+				}
+			} else {
+				return error()
+			}
+		}
+
+	case DataObject:
+		if element := createBackground(value); element != nil {
+			background = []BackgroundElement{element}
+		} else {
+			return error()
+		}
+
+	case []DataObject:
+		for _, obj := range value {
+			if element := createBackground(obj); element != nil {
+				background = append(background, element)
+			} else {
+				return error()
+			}
+		}
+
+	case string:
+		if obj := ParseDataText(value); obj != nil {
+			if element := createBackground(obj); element != nil {
+				background = []BackgroundElement{element}
+			} else {
+				return error()
+			}
+		} else {
+			return error()
+		}
+	}
+
+	if len(background) > 0 {
+		properties.setRaw(Background, background)
+	} else if properties.getRaw(Background) != nil {
+		properties.setRaw(Background, nil)
+	} else {
+		return []PropertyName{}
+	}
+
+	return []PropertyName{Background}
+}

backgroundConicGradient.go

@@ -21,7 +21,7 @@ type BackgroundGradientAngle struct {
 // NewBackgroundConicGradient creates the new background conic gradient
 func NewBackgroundConicGradient(params Params) BackgroundElement {
 	result := new(backgroundConicGradient)
-	result.properties = map[string]any{}
+	result.init()
 	for tag, value := range params {
 		result.Set(tag, value)
 	}
@@ -48,7 +48,6 @@ func (point *BackgroundGradientAngle) String() string {
 
 		case AngleUnit:
 			result += " " + value.String()
-
 		}
 	}
 
@@ -115,6 +114,15 @@ func (point *BackgroundGradientAngle) cssString(session Session, buffer *strings
 	}
 }
 
+func (gradient *backgroundConicGradient) init() {
+	gradient.backgroundElement.init()
+	gradient.normalize = normalizeConicGradientTag
+	gradient.set = backgroundConicGradientSet
+	gradient.supportedProperties = []PropertyName{
+		CenterX, CenterY, Repeating, From, Gradient,
+	}
+}
+
 func (gradient *backgroundConicGradient) Tag() string {
 	return "conic-gradient"
 }
@@ -127,8 +135,8 @@ func (image *backgroundConicGradient) Clone() BackgroundElement {
 	return result
 }
 
-func (gradient *backgroundConicGradient) normalizeTag(tag string) string {
+func normalizeConicGradientTag(tag PropertyName) PropertyName {
-	tag = strings.ToLower(tag)
+	tag = defaultNormalize(tag)
 	switch tag {
 	case "x-center":
 		tag = CenterX
@@ -140,18 +148,50 @@ func (gradient *backgroundConicGradient) normalizeTag(tag string) string {
 	return tag
 }
 
-func (gradient *backgroundConicGradient) Set(tag string, value any) bool {
+func backgroundConicGradientSet(properties Properties, tag PropertyName, value any) []PropertyName {
-	tag = gradient.normalizeTag(tag)
 	switch tag {
-	case CenterX, CenterY, Repeating, From:
-		return gradient.propertyList.Set(tag, value)
-
 	case Gradient:
-		return gradient.setGradient(value)
+		switch value := value.(type) {
+		case string:
+			if value == "" {
+				return propertiesRemove(properties, tag)
 			}
 
-	ErrorLogF(`"%s" property is not supported by BackgroundConicGradient`, tag)
+			if strings.Contains(value, ",") || strings.Contains(value, " ") {
-	return false
+				if vector := parseGradientText(value); vector != nil {
+					properties.setRaw(Gradient, vector)
+					return []PropertyName{tag}
+				}
+			} else if isConstantName(value) {
+				properties.setRaw(Gradient, value)
+				return []PropertyName{tag}
+			}
+
+			ErrorLogF(`Invalid conic gradient: "%s"`, value)
+
+		case []BackgroundGradientAngle:
+			count := len(value)
+			if count < 2 {
+				ErrorLog("The gradient must contain at least 2 points")
+				return nil
+			}
+
+			for i, point := range value {
+				if point.Color == nil {
+					ErrorLogF("Invalid %d element of the conic gradient: Color is nil", i)
+					return nil
+				}
+			}
+			properties.setRaw(Gradient, value)
+			return []PropertyName{tag}
+
+		default:
+			notCompatibleType(tag, value)
+		}
+		return nil
+	}
+
+	return propertiesSet(properties, tag, value)
 }
 
 func (gradient *backgroundConicGradient) stringToAngle(text string) (any, bool) {
@@ -216,57 +256,6 @@ func (gradient *backgroundConicGradient) parseGradientText(value string) []Backg
 	}
 	return vector
 }
-
-func (gradient *backgroundConicGradient) setGradient(value any) bool {
-	if value == nil {
-		delete(gradient.properties, Gradient)
-		return true
-	}
-
-	switch value := value.(type) {
-	case string:
-		if value == "" {
-			delete(gradient.properties, Gradient)
-			return true
-		}
-
-		if strings.Contains(value, ",") || strings.Contains(value, " ") {
-			if vector := gradient.parseGradientText(value); vector != nil {
-				gradient.properties[Gradient] = vector
-				return true
-			}
-			return false
-		} else if value[0] == '@' {
-			gradient.properties[Gradient] = value
-			return true
-		}
-
-		ErrorLogF(`Invalid conic gradient: "%s"`, value)
-		return false
-
-	case []BackgroundGradientAngle:
-		count := len(value)
-		if count < 2 {
-			ErrorLog("The gradient must contain at least 2 points")
-			return false
-		}
-
-		for i, point := range value {
-			if point.Color == nil {
-				ErrorLogF("Invalid %d element of the conic gradient: Color is nil", i)
-				return false
-			}
-		}
-		gradient.properties[Gradient] = value
-		return true
-	}
-	return false
-}
-
-func (gradient *backgroundConicGradient) Get(tag string) any {
-	return gradient.backgroundElement.Get(gradient.normalizeTag(tag))
-}
-
 func (gradient *backgroundConicGradient) cssStyle(session Session) string {
 
 	points := []BackgroundGradientAngle{}
@@ -339,7 +328,7 @@ func (gradient *backgroundConicGradient) cssStyle(session Session) string {
 }
 
 func (gradient *backgroundConicGradient) writeString(buffer *strings.Builder, indent string) {
-	gradient.writeToBuffer(buffer, indent, gradient.Tag(), []string{
+	gradient.writeToBuffer(buffer, indent, gradient.Tag(), []PropertyName{
 		Gradient,
 		CenterX,
 		CenterY,

backgroundGradient.go

@@ -72,7 +72,7 @@ type backgroundRadialGradient struct {
 // NewBackgroundLinearGradient creates the new background linear gradient
 func NewBackgroundLinearGradient(params Params) BackgroundElement {
 	result := new(backgroundLinearGradient)
-	result.properties = map[string]any{}
+	result.init()
 	for tag, value := range params {
 		result.Set(tag, value)
 	}
@@ -82,14 +82,14 @@ func NewBackgroundLinearGradient(params Params) BackgroundElement {
 // NewBackgroundRadialGradient creates the new background radial gradient
 func NewBackgroundRadialGradient(params Params) BackgroundElement {
 	result := new(backgroundRadialGradient)
-	result.properties = map[string]any{}
+	result.init()
 	for tag, value := range params {
 		result.Set(tag, value)
 	}
 	return result
 }
 
-func (gradient *backgroundGradient) parseGradientText(value string) []BackgroundGradientPoint {
+func parseGradientText(value string) []BackgroundGradientPoint {
 	elements := strings.Split(value, ",")
 	count := len(elements)
 	if count < 2 {
@@ -107,31 +107,31 @@ func (gradient *backgroundGradient) parseGradientText(value string) []Background
 	return points
 }
 
-func (gradient *backgroundGradient) Set(tag string, value any) bool {
+func backgroundGradientSet(properties Properties, tag PropertyName, value any) []PropertyName {
 
-	switch tag = strings.ToLower(tag); tag {
+	switch tag {
 	case Repeating:
-		return gradient.setBoolProperty(tag, value)
+		return setBoolProperty(properties, tag, value)
 
 	case Gradient:
 		switch value := value.(type) {
 		case string:
 			if value != "" {
 				if strings.Contains(value, " ") || strings.Contains(value, ",") {
-					if points := gradient.parseGradientText(value); len(points) >= 2 {
+					if points := parseGradientText(value); len(points) >= 2 {
-						gradient.properties[Gradient] = points
+						properties.setRaw(Gradient, points)
-						return true
+						return []PropertyName{tag}
 					}
 				} else if value[0] == '@' {
-					gradient.properties[Gradient] = value
+					properties.setRaw(Gradient, value)
-					return true
+					return []PropertyName{tag}
 				}
 			}
 
 		case []BackgroundGradientPoint:
 			if len(value) >= 2 {
-				gradient.properties[Gradient] = value
+				properties.setRaw(Gradient, value)
-				return true
+				return []PropertyName{tag}
 			}
 
 		case []Color:
@@ -141,8 +141,8 @@ func (gradient *backgroundGradient) Set(tag string, value any) bool {
 				for i, color := range value {
 					points[i].Color = color
 				}
-				gradient.properties[Gradient] = points
+				properties.setRaw(Gradient, points)
-				return true
+				return []PropertyName{tag}
 			}
 
 		case []GradientPoint:
@@ -153,17 +153,17 @@ func (gradient *backgroundGradient) Set(tag string, value any) bool {
 					points[i].Color = point.Color
 					points[i].Pos = Percent(point.Offset * 100)
 				}
-				gradient.properties[Gradient] = points
+				properties.setRaw(Gradient, points)
-				return true
+				return []PropertyName{tag}
 			}
 		}
 
 		ErrorLogF("Invalid gradient %v", value)
-		return false
+		return nil
 	}
 
 	ErrorLogF("Property %s is not supported by a background gradient", tag)
-	return false
+	return nil
 }
 
 func (point *BackgroundGradientPoint) setValue(text string) bool {
@@ -266,7 +266,7 @@ func (gradient *backgroundGradient) writeGradient(session Session, buffer *strin
 	case string:
 		if value != "" && value[0] == '@' {
 			if text, ok := session.Constant(value[1:]); ok {
-				points = gradient.parseGradientText(text)
+				points = parseGradientText(text)
 			}
 		}
 
@@ -312,6 +312,13 @@ func (gradient *backgroundGradient) writeGradient(session Session, buffer *strin
 	return false
 }
 
+func (gradient *backgroundLinearGradient) init() {
+	gradient.backgroundElement.init()
+	gradient.set = backgroundLinearGradientSet
+	gradient.supportedProperties = append(gradient.supportedProperties, Direction)
+
+}
+
 func (gradient *backgroundLinearGradient) Tag() string {
 	return "linear-gradient"
 }
@@ -324,26 +331,26 @@ func (image *backgroundLinearGradient) Clone() BackgroundElement {
 	return result
 }
 
-func (gradient *backgroundLinearGradient) Set(tag string, value any) bool {
+func backgroundLinearGradientSet(properties Properties, tag PropertyName, value any) []PropertyName {
-	if strings.ToLower(tag) == Direction {
+	if tag == Direction {
 		switch value := value.(type) {
 		case AngleUnit:
-			gradient.properties[Direction] = value
+			properties.setRaw(Direction, value)
-			return true
+			return []PropertyName{tag}
 
 		case string:
-			if gradient.setSimpleProperty(tag, value) {
+			if setSimpleProperty(properties, tag, value) {
-				return true
+				return []PropertyName{tag}
 			}
 			if angle, ok := StringToAngleUnit(value); ok {
-				gradient.properties[Direction] = angle
+				properties.setRaw(Direction, angle)
-				return true
+				return []PropertyName{tag}
 			}
 		}
-		return gradient.setEnumProperty(tag, value, enumProperties[Direction].values)
+		return setEnumProperty(properties, tag, value, enumProperties[Direction].values)
 	}
 
-	return gradient.backgroundGradient.Set(tag, value)
+	return backgroundGradientSet(properties, tag, value)
 }
 
 func (gradient *backgroundLinearGradient) cssStyle(session Session) string {
@@ -400,7 +407,7 @@ func (gradient *backgroundLinearGradient) cssStyle(session Session) string {
 }
 
 func (gradient *backgroundLinearGradient) writeString(buffer *strings.Builder, indent string) {
-	gradient.writeToBuffer(buffer, indent, gradient.Tag(), []string{
+	gradient.writeToBuffer(buffer, indent, gradient.Tag(), []PropertyName{
 		Gradient,
 		Repeating,
 		Direction,
@@ -411,6 +418,15 @@ func (gradient *backgroundLinearGradient) String() string {
 	return runStringWriter(gradient)
 }
 
+func (gradient *backgroundRadialGradient) init() {
+	gradient.backgroundElement.init()
+	gradient.normalize = normalizeRadialGradientTag
+	gradient.set = backgroundRadialGradientSet
+	gradient.supportedProperties = append(gradient.supportedProperties, []PropertyName{
+		RadialGradientRadius, RadialGradientShape, CenterX, CenterY,
+	}...)
+}
+
 func (gradient *backgroundRadialGradient) Tag() string {
 	return "radial-gradient"
 }
@@ -423,8 +439,8 @@ func (image *backgroundRadialGradient) Clone() BackgroundElement {
 	return result
 }
 
-func (gradient *backgroundRadialGradient) normalizeTag(tag string) string {
+func normalizeRadialGradientTag(tag PropertyName) PropertyName {
-	tag = strings.ToLower(tag)
+	tag = defaultNormalize(tag)
 	switch tag {
 	case Radius:
 		tag = RadialGradientRadius
@@ -442,83 +458,75 @@ func (gradient *backgroundRadialGradient) normalizeTag(tag string) string {
 	return tag
 }
 
-func (gradient *backgroundRadialGradient) Set(tag string, value any) bool {
+func backgroundRadialGradientSet(properties Properties, tag PropertyName, value any) []PropertyName {
-	tag = gradient.normalizeTag(tag)
 	switch tag {
 	case RadialGradientRadius:
 		switch value := value.(type) {
 		case []SizeUnit:
 			switch len(value) {
 			case 0:
-				delete(gradient.properties, RadialGradientRadius)
+				properties.setRaw(RadialGradientRadius, nil)
-				return true
 
 			case 1:
 				if value[0].Type == Auto {
-					delete(gradient.properties, RadialGradientRadius)
+					properties.setRaw(RadialGradientRadius, nil)
 				} else {
-					gradient.properties[RadialGradientRadius] = value[0]
+					properties.setRaw(RadialGradientRadius, value[0])
 				}
-				return true
 
 			default:
-				gradient.properties[RadialGradientRadius] = value
+				properties.setRaw(RadialGradientRadius, value)
-				return true
 			}
+			return []PropertyName{tag}
 
 		case []any:
 			switch len(value) {
 			case 0:
-				delete(gradient.properties, RadialGradientRadius)
+				properties.setRaw(RadialGradientRadius, nil)
-				return true
+				return []PropertyName{tag}
 
 			case 1:
-				return gradient.Set(RadialGradientRadius, value[0])
+				return backgroundRadialGradientSet(properties, RadialGradientRadius, value[0])
 
 			default:
-				gradient.properties[RadialGradientRadius] = value
+				properties.setRaw(RadialGradientRadius, value)
-				return true
+				return []PropertyName{tag}
 			}
 
 		case string:
-			if gradient.setSimpleProperty(RadialGradientRadius, value) {
+			if setSimpleProperty(properties, RadialGradientRadius, value) {
-				return true
+				return []PropertyName{tag}
 			}
 			if size, err := stringToSizeUnit(value); err == nil {
 				if size.Type == Auto {
-					delete(gradient.properties, RadialGradientRadius)
+					properties.setRaw(RadialGradientRadius, nil)
 				} else {
-					gradient.properties[RadialGradientRadius] = size
+					properties.setRaw(RadialGradientRadius, size)
 				}
-				return true
+				return []PropertyName{tag}
 			}
-			return gradient.setEnumProperty(RadialGradientRadius, value, enumProperties[RadialGradientRadius].values)
+			return setEnumProperty(properties, RadialGradientRadius, value, enumProperties[RadialGradientRadius].values)
 
 		case SizeUnit:
 			if value.Type == Auto {
-				delete(gradient.properties, RadialGradientRadius)
+				properties.setRaw(RadialGradientRadius, nil)
 			} else {
-				gradient.properties[RadialGradientRadius] = value
+				properties.setRaw(RadialGradientRadius, value)
 			}
-			return true
+			return []PropertyName{tag}
 
 		case int:
-			n := value
+			return setEnumProperty(properties, RadialGradientRadius, value, enumProperties[RadialGradientRadius].values)
-			if n >= 0 && n < len(enumProperties[RadialGradientRadius].values) {
-				return gradient.propertyList.Set(RadialGradientRadius, value)
-			}
 		}
+
 		ErrorLogF(`Invalid value of "%s" property: %v`, tag, value)
+		return nil
 
 	case RadialGradientShape, CenterX, CenterY:
-		return gradient.propertyList.Set(tag, value)
+		return propertiesSet(properties, tag, value)
 	}
 
-	return gradient.backgroundGradient.Set(tag, value)
+	return backgroundGradientSet(properties, tag, value)
-}
-
-func (gradient *backgroundRadialGradient) Get(tag string) any {
-	return gradient.backgroundGradient.Get(gradient.normalizeTag(tag))
 }
 
 func (gradient *backgroundRadialGradient) cssStyle(session Session) string {
@@ -652,7 +660,7 @@ func (gradient *backgroundRadialGradient) cssStyle(session Session) string {
 	return buffer.String()
 }
 func (gradient *backgroundRadialGradient) writeString(buffer *strings.Builder, indent string) {
-	gradient.writeToBuffer(buffer, indent, gradient.Tag(), []string{
+	gradient.writeToBuffer(buffer, indent, gradient.Tag(), []PropertyName{
 		Gradient,
 		CenterX,
 		CenterY,

border.go

@@ -38,7 +38,7 @@ const (
 	// `2`(`DashedLine`) or "dashed" - Dashed line as a border.
 	// `3`(`DottedLine`) or "dotted" - Dotted line as a border.
 	// `4`(`DoubleLine`) or "double" - Double line as a border.
-	LeftStyle = "left-style"
+	LeftStyle PropertyName = "left-style"
 
 	// RightStyle is the constant for "right-style" property tag.
 	//
@@ -53,7 +53,7 @@ const (
 	// `2`(`DashedLine`) or "dashed" - Dashed line as a border.
 	// `3`(`DottedLine`) or "dotted" - Dotted line as a border.
 	// `4`(`DoubleLine`) or "double" - Double line as a border.
-	RightStyle = "right-style"
+	RightStyle PropertyName = "right-style"
 
 	// TopStyle is the constant for "top-style" property tag.
 	//
@@ -68,7 +68,7 @@ const (
 	// `2`(`DashedLine`) or "dashed" - Dashed line as a border.
 	// `3`(`DottedLine`) or "dotted" - Dotted line as a border.
 	// `4`(`DoubleLine`) or "double" - Double line as a border.
-	TopStyle = "top-style"
+	TopStyle PropertyName = "top-style"
 
 	// BottomStyle is the constant for "bottom-style" property tag.
 	//
@@ -83,7 +83,7 @@ const (
 	// `2`(`DashedLine`) or "dashed" - Dashed line as a border.
 	// `3`(`DottedLine`) or "dotted" - Dotted line as a border.
 	// `4`(`DoubleLine`) or "double" - Double line as a border.
-	BottomStyle = "bottom-style"
+	BottomStyle PropertyName = "bottom-style"
 
 	// LeftWidth is the constant for "left-width" property tag.
 	//
@@ -94,7 +94,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	LeftWidth = "left-width"
+	LeftWidth PropertyName = "left-width"
 
 	// RightWidth is the constant for "right-width" property tag.
 	//
@@ -105,7 +105,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RightWidth = "right-width"
+	RightWidth PropertyName = "right-width"
 
 	// TopWidth is the constant for "top-width" property tag.
 	//
@@ -116,7 +116,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	TopWidth = "top-width"
+	TopWidth PropertyName = "top-width"
 
 	// BottomWidth is the constant for "bottom-width" property tag.
 	//
@@ -127,7 +127,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	BottomWidth = "bottom-width"
+	BottomWidth PropertyName = "bottom-width"
 
 	// LeftColor is the constant for "left-color" property tag.
 	//
@@ -138,7 +138,7 @@ const (
 	//
 	// Internal type is `Color`, other types converted to it during assignment.
 	// See `Color` description for more details.
-	LeftColor = "left-color"
+	LeftColor PropertyName = "left-color"
 
 	// RightColor is the constant for "right-color" property tag.
 	//
@@ -149,7 +149,7 @@ const (
 	//
 	// Internal type is `Color`, other types converted to it during assignment.
 	// See `Color` description for more details.
-	RightColor = "right-color"
+	RightColor PropertyName = "right-color"
 
 	// TopColor is the constant for "top-color" property tag.
 	//
@@ -160,7 +160,7 @@ const (
 	//
 	// Internal type is `Color`, other types converted to it during assignment.
 	// See `Color` description for more details.
-	TopColor = "top-color"
+	TopColor PropertyName = "top-color"
 
 	// BottomColor is the constant for "bottom-color" property tag.
 	//
@@ -171,7 +171,7 @@ const (
 	//
 	// Internal type is `Color`, other types converted to it during assignment.
 	// See `Color` description for more details.
-	BottomColor = "bottom-color"
+	BottomColor PropertyName = "bottom-color"
 )
 
 // BorderProperty is the interface of a view border data
@@ -183,7 +183,7 @@ type BorderProperty interface {
 	// ViewBorders returns top, right, bottom and left borders information all together
 	ViewBorders(session Session) ViewBorders
 
-	delete(tag string)
+	deleteTag(tag PropertyName) bool
 	cssStyle(builder cssBuilder, session Session)
 	cssWidth(builder cssBuilder, session Session)
 	cssColor(builder cssBuilder, session Session)
@@ -193,12 +193,12 @@ type BorderProperty interface {
 }
 
 type borderProperty struct {
-	propertyList
+	dataProperty
 }
 
 func newBorderProperty(value any) BorderProperty {
 	border := new(borderProperty)
-	border.properties = map[string]any{}
+	border.init()
 
 	if value != nil {
 		switch value := value.(type) {
@@ -270,9 +270,10 @@ func newBorderProperty(value any) BorderProperty {
 // "width" (Width). Determines the line thickness (SizeUnit).
 func NewBorder(params Params) BorderProperty {
 	border := new(borderProperty)
-	border.properties = map[string]any{}
+	border.init()
+
 	if params != nil {
-		for _, tag := range []string{Style, Width, ColorTag, Left, Right, Top, Bottom,
+		for _, tag := range []PropertyName{Style, Width, ColorTag, Left, Right, Top, Bottom,
 			LeftStyle, RightStyle, TopStyle, BottomStyle,
 			LeftWidth, RightWidth, TopWidth, BottomWidth,
 			LeftColor, RightColor, TopColor, BottomColor} {
@@ -284,8 +285,37 @@ func NewBorder(params Params) BorderProperty {
 	return border
 }
 
-func (border *borderProperty) normalizeTag(tag string) string {
+func (border *borderProperty) init() {
-	tag = strings.ToLower(tag)
+	border.dataProperty.init()
+	border.normalize = normalizeBorderTag
+	border.get = borderGet
+	border.set = borderSet
+	border.remove = borderRemove
+	border.supportedProperties = []PropertyName{
+		Left,
+		Right,
+		Top,
+		Bottom,
+		Style,
+		LeftStyle,
+		RightStyle,
+		TopStyle,
+		BottomStyle,
+		Width,
+		LeftWidth,
+		RightWidth,
+		TopWidth,
+		BottomWidth,
+		ColorTag,
+		LeftColor,
+		RightColor,
+		TopColor,
+		BottomColor,
+	}
+}
+
+func normalizeBorderTag(tag PropertyName) PropertyName {
+	tag = defaultNormalize(tag)
 	switch tag {
 	case BorderLeft, CellBorderLeft:
 		return Left
@@ -352,23 +382,23 @@ func (border *borderProperty) writeString(buffer *strings.Builder, indent string
 	buffer.WriteString("_{ ")
 	comma := false
 
-	write := func(tag string, value any) {
+	write := func(tag PropertyName, value any) {
 		if comma {
 			buffer.WriteString(", ")
 		}
-		buffer.WriteString(tag)
+		buffer.WriteString(string(tag))
 		buffer.WriteString(" = ")
 		writePropertyValue(buffer, BorderStyle, value, indent)
 		comma = true
 	}
 
-	for _, tag := range []string{Style, Width, ColorTag} {
+	for _, tag := range []PropertyName{Style, Width, ColorTag} {
 		if value, ok := border.properties[tag]; ok {
 			write(tag, value)
 		}
 	}
 
-	for _, side := range []string{Top, Right, Bottom, Left} {
+	for _, side := range []PropertyName{Top, Right, Bottom, Left} {
 		style, okStyle := border.properties[side+"-"+Style]
 		width, okWidth := border.properties[side+"-"+Width]
 		color, okColor := border.properties[side+"-"+ColorTag]
@@ -378,7 +408,7 @@ func (border *borderProperty) writeString(buffer *strings.Builder, indent string
 				comma = false
 			}
 
-			buffer.WriteString(side)
+			buffer.WriteString(string(side))
 			buffer.WriteString(" = _{ ")
 			if okStyle {
 				write(Style, style)
@@ -401,164 +431,96 @@ func (border *borderProperty) String() string {
 	return runStringWriter(border)
 }
 
-func (border *borderProperty) setSingleBorderObject(prefix string, obj DataObject) bool {
-	result := true
-	if text, ok := obj.PropertyValue(Style); ok {
-		if !border.setEnumProperty(prefix+"-style", text, enumProperties[BorderStyle].values) {
-			result = false
-		}
-	}
-	if text, ok := obj.PropertyValue(ColorTag); ok {
-		if !border.setColorProperty(prefix+"-color", text) {
-			result = false
-		}
-	}
-	if text, ok := obj.PropertyValue("width"); ok {
-		if !border.setSizeProperty(prefix+"-width", text) {
-			result = false
-		}
-	}
-	return result
-}
-
 func (border *borderProperty) setBorderObject(obj DataObject) bool {
 	result := true
+	for i := 0; i < obj.PropertyCount(); i++ {
+		if node := obj.Property(i); node != nil {
+			tag := PropertyName(node.Tag())
+			switch node.Type() {
+			case TextNode:
+				if borderSet(border, tag, node.Text()) == nil {
+					result = false
+				}
 
-	for _, side := range []string{Top, Right, Bottom, Left} {
+			case ObjectNode:
-		if node := obj.PropertyByTag(side); node != nil {
+				if borderSet(border, tag, node.Object()) == nil {
-			if node.Type() == ObjectNode {
+					result = false
-				if !border.setSingleBorderObject(side, node.Object()) {
+				}
+
+			default:
 				result = false
 			}
 		} else {
-				notCompatibleType(side, node)
 			result = false
 		}
 	}
-	}
-
-	if text, ok := obj.PropertyValue(Style); ok {
-		values := split4Values(text)
-		styles := enumProperties[BorderStyle].values
-		switch len(values) {
-		case 1:
-			if !border.setEnumProperty(Style, values[0], styles) {
-				result = false
-			}
-
-		case 4:
-			for n, tag := range [4]string{TopStyle, RightStyle, BottomStyle, LeftStyle} {
-				if !border.setEnumProperty(tag, values[n], styles) {
-					result = false
-				}
-			}
-
-		default:
-			notCompatibleType(Style, text)
-			result = false
-		}
-	}
-
-	if text, ok := obj.PropertyValue(ColorTag); ok {
-		values := split4Values(text)
-		switch len(values) {
-		case 1:
-			if !border.setColorProperty(ColorTag, values[0]) {
-				return false
-			}
-
-		case 4:
-			for n, tag := range [4]string{TopColor, RightColor, BottomColor, LeftColor} {
-				if !border.setColorProperty(tag, values[n]) {
-					return false
-				}
-			}
-
-		default:
-			notCompatibleType(ColorTag, text)
-			result = false
-		}
-	}
-
-	if text, ok := obj.PropertyValue(Width); ok {
-		values := split4Values(text)
-		switch len(values) {
-		case 1:
-			if !border.setSizeProperty(Width, values[0]) {
-				result = false
-			}
-
-		case 4:
-			for n, tag := range [4]string{TopWidth, RightWidth, BottomWidth, LeftWidth} {
-				if !border.setSizeProperty(tag, values[n]) {
-					result = false
-				}
-			}
-
-		default:
-			notCompatibleType(Width, text)
-			result = false
-		}
-	}
-
 	return result
 }
 
-func (border *borderProperty) Remove(tag string) {
+func borderRemove(properties Properties, tag PropertyName) []PropertyName {
-	tag = border.normalizeTag(tag)
+	result := []PropertyName{}
+	removeTag := func(t PropertyName) {
+		if properties.getRaw(t) != nil {
+			properties.setRaw(t, nil)
+			result = append(result, t)
+		}
+	}
 
 	switch tag {
 	case Style:
-		for _, t := range []string{tag, TopStyle, RightStyle, BottomStyle, LeftStyle} {
+		for _, t := range []PropertyName{tag, TopStyle, RightStyle, BottomStyle, LeftStyle} {
-			delete(border.properties, t)
+			removeTag(t)
 		}
 
 	case Width:
-		for _, t := range []string{tag, TopWidth, RightWidth, BottomWidth, LeftWidth} {
+		for _, t := range []PropertyName{tag, TopWidth, RightWidth, BottomWidth, LeftWidth} {
-			delete(border.properties, t)
+			removeTag(t)
 		}
 
 	case ColorTag:
-		for _, t := range []string{tag, TopColor, RightColor, BottomColor, LeftColor} {
+		for _, t := range []PropertyName{tag, TopColor, RightColor, BottomColor, LeftColor} {
-			delete(border.properties, t)
+			removeTag(t)
 		}
 
 	case Left, Right, Top, Bottom:
-		border.Remove(tag + "-style")
+		removeTag(tag + "-style")
-		border.Remove(tag + "-width")
+		removeTag(tag + "-width")
-		border.Remove(tag + "-color")
+		removeTag(tag + "-color")
 
 	case LeftStyle, RightStyle, TopStyle, BottomStyle:
-		delete(border.properties, tag)
+		removeTag(tag)
-		if style, ok := border.properties[Style]; ok && style != nil {
+		if style := properties.getRaw(Style); style != nil {
-			for _, t := range []string{TopStyle, RightStyle, BottomStyle, LeftStyle} {
+			for _, t := range []PropertyName{TopStyle, RightStyle, BottomStyle, LeftStyle} {
 				if t != tag {
-					if _, ok := border.properties[t]; !ok {
+					if properties.getRaw(t) == nil {
-						border.properties[t] = style
+						properties.setRaw(t, style)
+						result = append(result, t)
 					}
 				}
 			}
 		}
 
 	case LeftWidth, RightWidth, TopWidth, BottomWidth:
-		delete(border.properties, tag)
+		removeTag(tag)
-		if width, ok := border.properties[Width]; ok && width != nil {
+		if width := properties.getRaw(Width); width != nil {
-			for _, t := range []string{TopWidth, RightWidth, BottomWidth, LeftWidth} {
+			for _, t := range []PropertyName{TopWidth, RightWidth, BottomWidth, LeftWidth} {
 				if t != tag {
-					if _, ok := border.properties[t]; !ok {
+					if properties.getRaw(t) == nil {
-						border.properties[t] = width
+						properties.setRaw(t, width)
+						result = append(result, t)
 					}
 				}
 			}
 		}
 
 	case LeftColor, RightColor, TopColor, BottomColor:
-		delete(border.properties, tag)
+		removeTag(tag)
-		if color, ok := border.properties[ColorTag]; ok && color != nil {
+		if color := properties.getRaw(ColorTag); color != nil {
-			for _, t := range []string{TopColor, RightColor, BottomColor, LeftColor} {
+			for _, t := range []PropertyName{TopColor, RightColor, BottomColor, LeftColor} {
 				if t != tag {
-					if _, ok := border.properties[t]; !ok {
+					if properties.getRaw(t) == nil {
-						border.properties[t] = color
+						properties.setRaw(t, color)
+						result = append(result, t)
 					}
 				}
 			}
@@ -567,80 +529,118 @@ func (border *borderProperty) Remove(tag string) {
 	default:
 		ErrorLogF(`"%s" property is not compatible with the BorderProperty`, tag)
 	}
+
+	return result
 }
 
-func (border *borderProperty) Set(tag string, value any) bool {
+func borderSet(properties Properties, tag PropertyName, value any) []PropertyName {
-	if value == nil {
-		border.Remove(tag)
-		return true
-	}
 
-	tag = border.normalizeTag(tag)
+	setSingleBorderObject := func(prefix PropertyName, obj DataObject) []PropertyName {
+		result := []PropertyName{}
+		if text, ok := obj.PropertyValue(string(Style)); ok {
+			props := setEnumProperty(properties, prefix+"-style", text, enumProperties[BorderStyle].values)
+			if props == nil {
+				return nil
+			}
+			result = append(result, props...)
+		}
+		if text, ok := obj.PropertyValue(string(ColorTag)); ok {
+			props := setColorProperty(properties, prefix+"-color", text)
+			if props == nil && len(result) == 0 {
+				return nil
+			}
+			result = append(result, props...)
+		}
+		if text, ok := obj.PropertyValue("width"); ok {
+			props := setSizeProperty(properties, prefix+"-width", text)
+			if props == nil && len(result) == 0 {
+				return nil
+			}
+			result = append(result, props...)
+		}
+		if len(result) > 0 {
+			result = append(result, prefix)
+		}
+		return result
+	}
 
 	switch tag {
 	case Style:
-		if border.setEnumProperty(Style, value, enumProperties[BorderStyle].values) {
+		if result := setEnumProperty(properties, Style, value, enumProperties[BorderStyle].values); result != nil {
-			for _, side := range []string{TopStyle, RightStyle, BottomStyle, LeftStyle} {
+			for _, side := range []PropertyName{TopStyle, RightStyle, BottomStyle, LeftStyle} {
-				delete(border.properties, side)
+				if value := properties.getRaw(side); value != nil {
+					properties.setRaw(side, nil)
+					result = append(result, side)
 				}
-			return true
+			}
+			return result
 		}
 
 	case Width:
-		if border.setSizeProperty(Width, value) {
+		if result := setSizeProperty(properties, Width, value); result != nil {
-			for _, side := range []string{TopWidth, RightWidth, BottomWidth, LeftWidth} {
+			for _, side := range []PropertyName{TopWidth, RightWidth, BottomWidth, LeftWidth} {
-				delete(border.properties, side)
+				if value := properties.getRaw(side); value != nil {
+					properties.setRaw(side, nil)
+					result = append(result, side)
 				}
-			return true
+			}
+			return result
 		}
 
 	case ColorTag:
-		if border.setColorProperty(ColorTag, value) {
+		if result := setColorProperty(properties, ColorTag, value); result != nil {
-			for _, side := range []string{TopColor, RightColor, BottomColor, LeftColor} {
+			for _, side := range []PropertyName{TopColor, RightColor, BottomColor, LeftColor} {
-				delete(border.properties, side)
+				if value := properties.getRaw(side); value != nil {
+					properties.setRaw(side, nil)
+					result = append(result, side)
 				}
-			return true
+			}
+			return result
 		}
 
 	case LeftStyle, RightStyle, TopStyle, BottomStyle:
-		return border.setEnumProperty(tag, value, enumProperties[BorderStyle].values)
+		return setEnumProperty(properties, tag, value, enumProperties[BorderStyle].values)
 
 	case LeftWidth, RightWidth, TopWidth, BottomWidth:
-		return border.setSizeProperty(tag, value)
+		return setSizeProperty(properties, tag, value)
 
 	case LeftColor, RightColor, TopColor, BottomColor:
-		return border.setColorProperty(tag, value)
+		return setColorProperty(properties, tag, value)
 
 	case Left, Right, Top, Bottom:
 		switch value := value.(type) {
 		case string:
 			if obj := ParseDataText(value); obj != nil {
-				return border.setSingleBorderObject(tag, obj)
+				return setSingleBorderObject(tag, obj)
 			}
 
 		case DataObject:
-			return border.setSingleBorderObject(tag, value)
+			return setSingleBorderObject(tag, value)
 
 		case BorderProperty:
+			result := []PropertyName{}
 			styleTag := tag + "-" + Style
 			if style := value.Get(styleTag); value != nil {
-				border.properties[styleTag] = style
+				properties.setRaw(styleTag, style)
+				result = append(result, styleTag)
 			}
 			colorTag := tag + "-" + ColorTag
 			if color := value.Get(colorTag); value != nil {
-				border.properties[colorTag] = color
+				properties.setRaw(colorTag, color)
+				result = append(result, colorTag)
 			}
 			widthTag := tag + "-" + Width
 			if width := value.Get(widthTag); value != nil {
-				border.properties[widthTag] = width
+				properties.setRaw(widthTag, width)
+				result = append(result, widthTag)
 			}
-			return true
+			return result
 
 		case ViewBorder:
-			border.properties[tag+"-"+Style] = value.Style
+			properties.setRaw(tag+"-"+Style, value.Style)
-			border.properties[tag+"-"+Width] = value.Width
+			properties.setRaw(tag+"-"+Width, value.Width)
-			border.properties[tag+"-"+ColorTag] = value.Color
+			properties.setRaw(tag+"-"+ColorTag, value.Color)
-			return true
+			return []PropertyName{tag + "-" + Style, tag + "-" + Width, tag + "-" + ColorTag}
 		}
 		fallthrough
 
@@ -648,105 +648,119 @@ func (border *borderProperty) Set(tag string, value any) bool {
 		ErrorLogF(`"%s" property is not compatible with the BorderProperty`, tag)
 	}
 
-	return false
+	return nil
 }
 
-func (border *borderProperty) Get(tag string) any {
+func borderGet(properties Properties, tag PropertyName) any {
-	tag = border.normalizeTag(tag)
+	if result := properties.getRaw(tag); result != nil {
-
-	if result, ok := border.properties[tag]; ok {
 		return result
 	}
 
 	switch tag {
 	case Left, Right, Top, Bottom:
 		result := newBorderProperty(nil)
-		if style, ok := border.properties[tag+"-"+Style]; ok {
+		if style := properties.getRaw(tag + "-" + Style); style != nil {
 			result.Set(Style, style)
-		} else if style, ok := border.properties[Style]; ok {
+		} else if style := properties.getRaw(Style); style != nil {
 			result.Set(Style, style)
 		}
-		if width, ok := border.properties[tag+"-"+Width]; ok {
+		if width := properties.getRaw(tag + "-" + Width); width != nil {
 			result.Set(Width, width)
-		} else if width, ok := border.properties[Width]; ok {
+		} else if width := properties.getRaw(Width); width != nil {
 			result.Set(Width, width)
 		}
-		if color, ok := border.properties[tag+"-"+ColorTag]; ok {
+		if color := properties.getRaw(tag + "-" + ColorTag); color != nil {
 			result.Set(ColorTag, color)
-		} else if color, ok := border.properties[ColorTag]; ok {
+		} else if color := properties.getRaw(ColorTag); color != nil {
 			result.Set(ColorTag, color)
 		}
 		return result
 
 	case LeftStyle, RightStyle, TopStyle, BottomStyle:
-		if style, ok := border.properties[tag]; ok {
+		if style := properties.getRaw(tag); style != nil {
 			return style
 		}
-		return border.properties[Style]
+		return properties.getRaw(Style)
 
 	case LeftWidth, RightWidth, TopWidth, BottomWidth:
-		if width, ok := border.properties[tag]; ok {
+		if width := properties.getRaw(tag); width != nil {
 			return width
 		}
-		return border.properties[Width]
+		return properties.getRaw(Width)
 
 	case LeftColor, RightColor, TopColor, BottomColor:
-		if color, ok := border.properties[tag]; ok {
+		if color := properties.getRaw(tag); color != nil {
 			return color
 		}
-		return border.properties[ColorTag]
+		return properties.getRaw(ColorTag)
 	}
 
 	return nil
 }
 
-func (border *borderProperty) delete(tag string) {
+func (border *borderProperty) deleteTag(tag PropertyName) bool {
-	tag = border.normalizeTag(tag)
+
-	remove := []string{}
+	result := false
+	removeTags := func(tags []PropertyName) {
+		for _, tag := range tags {
+			if border.getRaw(tag) != nil {
+				border.setRaw(tag, nil)
+				result = true
+			}
+		}
+	}
 
 	switch tag {
 	case Style:
-		remove = []string{Style, LeftStyle, RightStyle, TopStyle, BottomStyle}
+		removeTags([]PropertyName{Style, LeftStyle, RightStyle, TopStyle, BottomStyle})
 
 	case Width:
-		remove = []string{Width, LeftWidth, RightWidth, TopWidth, BottomWidth}
+		removeTags([]PropertyName{Width, LeftWidth, RightWidth, TopWidth, BottomWidth})
 
 	case ColorTag:
-		remove = []string{ColorTag, LeftColor, RightColor, TopColor, BottomColor}
+		removeTags([]PropertyName{ColorTag, LeftColor, RightColor, TopColor, BottomColor})
 
 	case Left, Right, Top, Bottom:
 		if border.Get(Style) != nil {
 			border.properties[tag+"-"+Style] = 0
-			remove = []string{tag + "-" + ColorTag, tag + "-" + Width}
+			result = true
+			removeTags([]PropertyName{tag + "-" + ColorTag, tag + "-" + Width})
 		} else {
-			remove = []string{tag + "-" + Style, tag + "-" + ColorTag, tag + "-" + Width}
+			removeTags([]PropertyName{tag + "-" + Style, tag + "-" + ColorTag, tag + "-" + Width})
 		}
 
 	case LeftStyle, RightStyle, TopStyle, BottomStyle:
+		if border.getRaw(tag) != nil {
 			if border.Get(Style) != nil {
 				border.properties[tag] = 0
+				result = true
 			} else {
-			remove = []string{tag}
+				removeTags([]PropertyName{tag})
+			}
 		}
 
 	case LeftWidth, RightWidth, TopWidth, BottomWidth:
+		if border.getRaw(tag) != nil {
 			if border.Get(Width) != nil {
 				border.properties[tag] = AutoSize()
+				result = true
 			} else {
-			remove = []string{tag}
+				removeTags([]PropertyName{tag})
+			}
 		}
 
 	case LeftColor, RightColor, TopColor, BottomColor:
+		if border.getRaw(tag) != nil {
 			if border.Get(ColorTag) != nil {
 				border.properties[tag] = 0
+				result = true
 			} else {
-			remove = []string{tag}
+				removeTags([]PropertyName{tag})
+			}
 		}
 	}
 
-	for _, tag := range remove {
+	return result
-		delete(border.properties, tag)
-	}
 }
 
 func (border *borderProperty) ViewBorders(session Session) ViewBorders {
@@ -755,7 +769,7 @@ func (border *borderProperty) ViewBorders(session Session) ViewBorders {
 	defWidth, _ := sizeProperty(border, Width, session)
 	defColor, _ := colorProperty(border, ColorTag, session)
 
-	getBorder := func(prefix string) ViewBorder {
+	getBorder := func(prefix PropertyName) ViewBorder {
 		var result ViewBorder
 		var ok bool
 		if result.Style, ok = valueToEnum(border.getRaw(prefix+Style), BorderStyle, session, NoneLine); !ok {
@@ -784,9 +798,9 @@ func (border *borderProperty) cssStyle(builder cssBuilder, session Session) {
 	if borders.Top.Style == borders.Right.Style &&
 		borders.Top.Style == borders.Left.Style &&
 		borders.Top.Style == borders.Bottom.Style {
-		builder.add(BorderStyle, values[borders.Top.Style])
+		builder.add(string(BorderStyle), values[borders.Top.Style])
 	} else {
-		builder.addValues(BorderStyle, " ", values[borders.Top.Style],
+		builder.addValues(string(BorderStyle), " ", values[borders.Top.Style],
 			values[borders.Right.Style], values[borders.Bottom.Style], values[borders.Left.Style])
 	}
 }
@@ -870,11 +884,25 @@ func (border *ViewBorders) AllTheSame() bool {
 		border.Top.Width.Equal(border.Bottom.Width)
 }
 
-func getBorder(style Properties, tag string) BorderProperty {
+func getBorderProperty(properties Properties, tag PropertyName) BorderProperty {
-	if value := style.Get(tag); value != nil {
+	if value := properties.getRaw(tag); value != nil {
 		if border, ok := value.(BorderProperty); ok {
 			return border
 		}
 	}
 	return nil
 }
+
+func setBorderPropertyElement(properties Properties, mainTag, tag PropertyName, value any) []PropertyName {
+	border := getBorderProperty(properties, mainTag)
+	if border == nil {
+		border = NewBorder(nil)
+		if border.Set(tag, value) {
+			properties.setRaw(mainTag, border)
+			return []PropertyName{mainTag, tag}
+		}
+	} else if border.Set(tag, value) {
+		return []PropertyName{mainTag, tag}
+	}
+	return nil
+}

bounds.go

@@ -16,26 +16,33 @@ type BoundsProperty interface {
 }
 
 type boundsPropertyData struct {
-	propertyList
+	dataProperty
 }
 
 // NewBoundsProperty creates the new BoundsProperty object.
 // The following SizeUnit properties can be used: "left" (Left), "right" (Right), "top" (Top), and "bottom" (Bottom).
 func NewBoundsProperty(params Params) BoundsProperty {
 	bounds := new(boundsPropertyData)
-	bounds.properties = map[string]any{}
+	bounds.init()
+
 	if params != nil {
-		for _, tag := range []string{Top, Right, Bottom, Left} {
+		for _, tag := range bounds.supportedProperties {
-			if value, ok := params[tag]; ok {
+			if value, ok := params[tag]; ok && value != nil {
-				bounds.Set(tag, value)
+				bounds.set(bounds, tag, value)
 			}
 		}
 	}
 	return bounds
 }
 
-func (bounds *boundsPropertyData) normalizeTag(tag string) string {
+func (bounds *boundsPropertyData) init() {
-	tag = strings.ToLower(tag)
+	bounds.dataProperty.init()
+	bounds.normalize = normalizeBoundsTag
+	bounds.supportedProperties = []PropertyName{Top, Right, Bottom, Left}
+}
+
+func normalizeBoundsTag(tag PropertyName) PropertyName {
+	tag = defaultNormalize(tag)
 	switch tag {
 	case MarginTop, PaddingTop, CellPaddingTop,
 		"top-margin", "top-padding", "top-cell-padding":
@@ -64,12 +71,12 @@ func (bounds *boundsPropertyData) String() string {
 func (bounds *boundsPropertyData) writeString(buffer *strings.Builder, indent string) {
 	buffer.WriteString("_{ ")
 	comma := false
-	for _, tag := range []string{Top, Right, Bottom, Left} {
+	for _, tag := range []PropertyName{Top, Right, Bottom, Left} {
 		if value, ok := bounds.properties[tag]; ok {
 			if comma {
 				buffer.WriteString(", ")
 			}
-			buffer.WriteString(tag)
+			buffer.WriteString(string(tag))
 			buffer.WriteString(" = ")
 			writePropertyValue(buffer, tag, value, indent)
 			comma = true
@@ -78,38 +85,6 @@ func (bounds *boundsPropertyData) writeString(buffer *strings.Builder, indent st
 	buffer.WriteString(" }")
 }
 
-func (bounds *boundsPropertyData) Remove(tag string) {
-	bounds.propertyList.Remove(bounds.normalizeTag(tag))
-}
-
-func (bounds *boundsPropertyData) Set(tag string, value any) bool {
-	if value == nil {
-		bounds.Remove(tag)
-		return true
-	}
-
-	tag = bounds.normalizeTag(tag)
-
-	switch tag {
-	case Top, Right, Bottom, Left:
-		return bounds.setSizeProperty(tag, value)
-
-	default:
-		ErrorLogF(`"%s" property is not compatible with the BoundsProperty`, tag)
-	}
-
-	return false
-}
-
-func (bounds *boundsPropertyData) Get(tag string) any {
-	tag = bounds.normalizeTag(tag)
-	if value, ok := bounds.properties[tag]; ok {
-		return value
-	}
-
-	return nil
-}
-
 func (bounds *boundsPropertyData) Bounds(session Session) Bounds {
 	top, _ := sizeProperty(bounds, Top, session)
 	right, _ := sizeProperty(bounds, Right, session)
@@ -141,7 +116,7 @@ func (bounds *Bounds) SetAll(value SizeUnit) {
 	bounds.Left = value
 }
 
-func (bounds *Bounds) setFromProperties(tag, topTag, rightTag, bottomTag, leftTag string, properties Properties, session Session) {
+func (bounds *Bounds) setFromProperties(tag, topTag, rightTag, bottomTag, leftTag PropertyName, properties Properties, session Session) {
 	bounds.Top = AutoSize()
 	if size, ok := sizeProperty(properties, tag, session); ok {
 		bounds.Top = size
@@ -216,11 +191,11 @@ func (bounds *Bounds) String() string {
 		bounds.Bottom.String() + "," + bounds.Left.String()
 }
 
-func (bounds *Bounds) cssValue(tag string, builder cssBuilder, session Session) {
+func (bounds *Bounds) cssValue(tag PropertyName, builder cssBuilder, session Session) {
 	if bounds.allFieldsEqual() {
-		builder.add(tag, bounds.Top.cssString("0", session))
+		builder.add(string(tag), bounds.Top.cssString("0", session))
 	} else {
-		builder.addValues(tag, " ",
+		builder.addValues(string(tag), " ",
 			bounds.Top.cssString("0", session),
 			bounds.Right.cssString("0", session),
 			bounds.Bottom.cssString("0", session),
@@ -234,8 +209,8 @@ func (bounds *Bounds) cssString(session Session) string {
 	return builder.finish()
 }
 
-func (properties *propertyList) setBounds(tag string, value any) bool {
+func setBoundsProperty(properties Properties, tag PropertyName, value any) []PropertyName {
-	if !properties.setSimpleProperty(tag, value) {
+	if !setSimpleProperty(properties, tag, value) {
 		switch value := value.(type) {
 		case string:
 			if strings.Contains(value, ",") {
@@ -247,88 +222,119 @@ func (properties *propertyList) setBounds(tag string, value any) bool {
 
 				case 4:
 					bounds := NewBoundsProperty(nil)
-					for i, tag := range []string{Top, Right, Bottom, Left} {
+					for i, tag := range []PropertyName{Top, Right, Bottom, Left} {
 						if !bounds.Set(tag, values[i]) {
-							notCompatibleType(tag, value)
+							return nil
-							return false
 						}
 					}
-					properties.properties[tag] = bounds
+					properties.setRaw(tag, bounds)
-					return true
+					return []PropertyName{tag}
 
 				default:
 					notCompatibleType(tag, value)
-					return false
+					return nil
 				}
 			}
-			return properties.setSizeProperty(tag, value)
+			return setSizeProperty(properties, tag, value)
 
 		case SizeUnit:
-			properties.properties[tag] = value
+			properties.setRaw(tag, value)
 
 		case float32:
-			properties.properties[tag] = Px(float64(value))
+			properties.setRaw(tag, Px(float64(value)))
 
 		case float64:
-			properties.properties[tag] = Px(value)
+			properties.setRaw(tag, Px(value))
 
 		case Bounds:
 			bounds := NewBoundsProperty(nil)
 			if value.Top.Type != Auto {
-				bounds.Set(Top, value.Top)
+				bounds.setRaw(Top, value.Top)
 			}
 			if value.Right.Type != Auto {
-				bounds.Set(Right, value.Right)
+				bounds.setRaw(Right, value.Right)
 			}
 			if value.Bottom.Type != Auto {
-				bounds.Set(Bottom, value.Bottom)
+				bounds.setRaw(Bottom, value.Bottom)
 			}
 			if value.Left.Type != Auto {
-				bounds.Set(Left, value.Left)
+				bounds.setRaw(Left, value.Left)
 			}
-			properties.properties[tag] = bounds
+			properties.setRaw(tag, bounds)
 
 		case BoundsProperty:
-			properties.properties[tag] = value
+			properties.setRaw(tag, value)
 
 		case DataObject:
 			bounds := NewBoundsProperty(nil)
-			for _, tag := range []string{Top, Right, Bottom, Left} {
+			for _, tag := range []PropertyName{Top, Right, Bottom, Left} {
-				if text, ok := value.PropertyValue(tag); ok {
+				if text, ok := value.PropertyValue(string(tag)); ok {
 					if !bounds.Set(tag, text) {
 						notCompatibleType(tag, value)
-						return false
+						return nil
 					}
 				}
 			}
-			properties.properties[tag] = bounds
+			properties.setRaw(tag, bounds)
 
 		default:
 			if n, ok := isInt(value); ok {
-				properties.properties[tag] = Px(float64(n))
+				properties.setRaw(tag, Px(float64(n)))
 			} else {
 				notCompatibleType(tag, value)
-				return false
+				return nil
 			}
 		}
 	}
 
-	return true
+	return []PropertyName{tag}
 }
 
-func (properties *propertyList) boundsProperty(tag string) BoundsProperty {
+func removeBoundsPropertySide(properties Properties, mainTag, sideTag PropertyName) []PropertyName {
-	if value, ok := properties.properties[tag]; ok {
+	if bounds := getBoundsProperty(properties, mainTag); bounds != nil {
+		if bounds.getRaw(sideTag) != nil {
+			bounds.Remove(sideTag)
+			if bounds.empty() {
+				bounds = nil
+			}
+			properties.setRaw(mainTag, bounds)
+			return []PropertyName{mainTag, sideTag}
+		}
+	}
+	return []PropertyName{}
+}
+
+func setBoundsPropertySide(properties Properties, mainTag, sideTag PropertyName, value any) []PropertyName {
+	if value == nil {
+		return removeBoundsPropertySide(properties, mainTag, sideTag)
+	}
+
+	bounds := getBoundsProperty(properties, mainTag)
+	if bounds == nil {
+		bounds = NewBoundsProperty(nil)
+	}
+	if bounds.Set(sideTag, value) {
+		properties.setRaw(mainTag, bounds)
+		return []PropertyName{mainTag, sideTag}
+	}
+
+	notCompatibleType(sideTag, value)
+	return nil
+}
+
+func getBoundsProperty(properties Properties, tag PropertyName) BoundsProperty {
+	if value := properties.getRaw(tag); value != nil {
 		switch value := value.(type) {
 		case string:
 			bounds := NewBoundsProperty(nil)
-			for _, t := range []string{Top, Right, Bottom, Left} {
+			for _, t := range []PropertyName{Top, Right, Bottom, Left} {
 				bounds.Set(t, value)
 			}
 			return bounds
 
 		case SizeUnit:
 			bounds := NewBoundsProperty(nil)
-			for _, t := range []string{Top, Right, Bottom, Left} {
+			for _, t := range []PropertyName{Top, Right, Bottom, Left} {
 				bounds.Set(t, value)
 			}
 			return bounds
@@ -345,29 +351,10 @@ func (properties *propertyList) boundsProperty(tag string) BoundsProperty {
 		}
 	}
 
-	return NewBoundsProperty(nil)
+	return nil
 }
 
-func (properties *propertyList) removeBoundsSide(mainTag, sideTag string) {
+func getBounds(properties Properties, tag PropertyName, session Session) (Bounds, bool) {
-	bounds := properties.boundsProperty(mainTag)
-	if bounds.Get(sideTag) != nil {
-		bounds.Remove(sideTag)
-		properties.properties[mainTag] = bounds
-	}
-}
-
-func (properties *propertyList) setBoundsSide(mainTag, sideTag string, value any) bool {
-	bounds := properties.boundsProperty(mainTag)
-	if bounds.Set(sideTag, value) {
-		properties.properties[mainTag] = bounds
-		return true
-	}
-
-	notCompatibleType(sideTag, value)
-	return false
-}
-
-func boundsProperty(properties Properties, tag string, session Session) (Bounds, bool) {
 	if value := properties.Get(tag); value != nil {
 		switch value := value.(type) {
 		case string:

button.go

@@ -18,6 +18,7 @@ func NewButton(session Session, params Params) Button {
 
 func newButton(session Session) View {
 	return NewButton(session, nil)
+	//return new(buttonData)
 }
 
 func (button *buttonData) CreateSuperView(session Session) View {

canvasView.go

@@ -1,14 +1,12 @@
 package rui
 
-import "strings"
-
 // DrawFunction is the constant for "draw-function" property tag.
 //
 // Used by `CanvasView`.
 // Property sets the draw function of `CanvasView`.
 //
 // Supported types: `func(Canvas)`.
-const DrawFunction = "draw-function"
+const DrawFunction PropertyName = "draw-function"
 
 // CanvasView interface of a custom draw view
 type CanvasView interface {
@@ -20,7 +18,6 @@ type CanvasView interface {
 
 type canvasViewData struct {
 	viewData
-	drawer func(Canvas)
 }
 
 // NewCanvasView creates the new custom draw view
@@ -32,21 +29,21 @@ func NewCanvasView(session Session, params Params) CanvasView {
 }
 
 func newCanvasView(session Session) View {
-	return NewCanvasView(session, nil)
+	return new(canvasViewData)
 }
 
 // Init initialize fields of ViewsContainer by default values
 func (canvasView *canvasViewData) init(session Session) {
 	canvasView.viewData.init(session)
 	canvasView.tag = "CanvasView"
+	canvasView.normalize = normalizeCanvasViewTag
+	canvasView.set = canvasViewSet
+	canvasView.remove = canvasViewRemove
+
 }
 
-func (canvasView *canvasViewData) String() string {
+func normalizeCanvasViewTag(tag PropertyName) PropertyName {
-	return getViewString(canvasView, nil)
+	tag = defaultNormalize(tag)
-}
-
-func (canvasView *canvasViewData) normalizeTag(tag string) string {
-	tag = strings.ToLower(tag)
 	switch tag {
 	case "draw-func":
 		tag = DrawFunction
@@ -54,51 +51,36 @@ func (canvasView *canvasViewData) normalizeTag(tag string) string {
 	return tag
 }
 
-func (canvasView *canvasViewData) Remove(tag string) {
+func canvasViewRemove(view View, tag PropertyName) []PropertyName {
-	canvasView.remove(canvasView.normalizeTag(tag))
-}
-
-func (canvasView *canvasViewData) remove(tag string) {
 	if tag == DrawFunction {
-		canvasView.drawer = nil
+		if view.getRaw(DrawFunction) != nil {
+			view.setRaw(DrawFunction, nil)
+			if canvasView, ok := view.(CanvasView); ok {
 				canvasView.Redraw()
-		canvasView.propertyChangedEvent(tag)
-	} else {
-		canvasView.viewData.remove(tag)
 			}
+			return []PropertyName{DrawFunction}
+		}
+		return []PropertyName{}
 	}
 
-func (canvasView *canvasViewData) Set(tag string, value any) bool {
+	return viewRemove(view, tag)
-	return canvasView.set(canvasView.normalizeTag(tag), value)
 }
 
-func (canvasView *canvasViewData) set(tag string, value any) bool {
+func canvasViewSet(view View, tag PropertyName, value any) []PropertyName {
 	if tag == DrawFunction {
-		if value == nil {
+		if fn, ok := value.(func(Canvas)); ok {
-			canvasView.drawer = nil
+			view.setRaw(DrawFunction, fn)
-		} else if fn, ok := value.(func(Canvas)); ok {
-			canvasView.drawer = fn
 		} else {
 			notCompatibleType(tag, value)
-			return false
+			return nil
 		}
+		if canvasView, ok := view.(CanvasView); ok {
 			canvasView.Redraw()
-		canvasView.propertyChangedEvent(tag)
+		}
-		return true
+		return []PropertyName{DrawFunction}
 	}
 
-	return canvasView.viewData.set(tag, value)
+	return viewSet(view, tag, value)
-}
-
-func (canvasView *canvasViewData) Get(tag string) any {
-	return canvasView.get(canvasView.normalizeTag(tag))
-}
-
-func (canvasView *canvasViewData) get(tag string) any {
-	if tag == DrawFunction {
-		return canvasView.drawer
-	}
-	return canvasView.viewData.get(tag)
 }
 
 func (canvasView *canvasViewData) htmlTag() string {
@@ -106,15 +88,15 @@ func (canvasView *canvasViewData) htmlTag() string {
 }
 
 func (canvasView *canvasViewData) Redraw() {
-	if canvasView.drawer != nil {
 	canvas := newCanvas(canvasView)
 	canvas.ClearRect(0, 0, canvasView.frame.Width, canvasView.frame.Height)
-		if canvasView.drawer != nil {
+	if value := canvasView.getRaw(DrawFunction); value != nil {
-			canvasView.drawer(canvas)
+		if drawer, ok := value.(func(Canvas)); ok {
+			drawer(canvas)
+		}
 	}
 	canvas.finishDraw()
 }
-}
 
 func (canvasView *canvasViewData) onResize(self View, x, y, width, height float64) {
 	canvasView.viewData.onResize(self, x, y, width, height)

checkbox.go

@@ -20,7 +20,7 @@ import (
 // `func(checkbox rui.Checkbox)`,
 // `func(checked bool)`,
 // `func()`.
-const CheckboxChangedEvent = "checkbox-event"
+const CheckboxChangedEvent PropertyName = "checkbox-event"
 
 // Checkbox represent a Checkbox view
 type Checkbox interface {
@@ -29,171 +29,132 @@ type Checkbox interface {
 
 type checkboxData struct {
 	viewsContainerData
-	checkedListeners []func(Checkbox, bool)
 }
 
 // NewCheckbox create new Checkbox object and return it
 func NewCheckbox(session Session, params Params) Checkbox {
 	view := new(checkboxData)
 	view.init(session)
-	setInitParams(view, Params{
-		ClickEvent:   checkboxClickListener,
-		KeyDownEvent: checkboxKeyListener,
-	})
 	setInitParams(view, params)
 	return view
 }
 
 func newCheckbox(session Session) View {
-	return NewCheckbox(session, nil)
+	return new(checkboxData)
 }
 
 func (button *checkboxData) init(session Session) {
 	button.viewsContainerData.init(session)
 	button.tag = "Checkbox"
 	button.systemClass = "ruiGridLayout ruiCheckbox"
-	button.checkedListeners = []func(Checkbox, bool){}
+	button.set = button.setFunc
-}
+	button.remove = button.removeFunc
+	button.changed = checkboxPropertyChanged
 
-func (button *checkboxData) String() string {
+	button.setRaw(ClickEvent, checkboxClickListener)
-	return getViewString(button, nil)
+	button.setRaw(KeyDownEvent, checkboxKeyListener)
 }
 
 func (button *checkboxData) Focusable() bool {
 	return true
 }
 
-func (button *checkboxData) Get(tag string) any {
+func checkboxPropertyChanged(view View, tag PropertyName) {
-	switch strings.ToLower(tag) {
-	case CheckboxChangedEvent:
-		return button.checkedListeners
-	}
-
-	return button.viewsContainerData.Get(tag)
-}
-
-func (button *checkboxData) Set(tag string, value any) bool {
-	return button.set(tag, value)
-}
-
-func (button *checkboxData) set(tag string, value any) bool {
 	switch tag {
-	case CheckboxChangedEvent:
-		if !button.setChangedListener(value) {
-			notCompatibleType(tag, value)
-			return false
-		}
 
 	case Checked:
-		oldChecked := button.checked()
+		session := view.Session()
-		if !button.setBoolProperty(Checked, value) {
+		checked := IsCheckboxChecked(view)
-			return false
+		if listeners := GetCheckboxChangedListeners(view); len(listeners) > 0 {
-		}
+			if checkbox, ok := view.(Checkbox); ok {
-		if button.created {
+				for _, listener := range listeners {
-			checked := button.checked()
+					listener(checkbox, checked)
-			if checked != oldChecked {
-				button.changedCheckboxState(checked)
 				}
 			}
+		}
+
+		buffer := allocStringBuilder()
+		defer freeStringBuilder(buffer)
+
+		checkboxHtml(view, buffer, checked)
+		session.updateInnerHTML(view.htmlID()+"checkbox", buffer.String())
 
 	case CheckboxHorizontalAlign, CheckboxVerticalAlign:
-		if !button.setEnumProperty(tag, value, enumProperties[tag].values) {
+		htmlID := view.htmlID()
-			return false
+		session := view.Session()
-		}
+		updateCSSStyle(htmlID, session)
-		if button.created {
+		updateInnerHTML(htmlID, session)
-			htmlID := button.htmlID()
-			updateCSSStyle(htmlID, button.session)
-			updateInnerHTML(htmlID, button.session)
-		}
 
 	case VerticalAlign:
-		if !button.setEnumProperty(tag, value, enumProperties[tag].values) {
+		view.Session().updateCSSProperty(view.htmlID()+"content", "align-items", checkboxVerticalAlignCSS(view))
-			return false
-		}
-		if button.created {
-			button.session.updateCSSProperty(button.htmlID()+"content", "align-items", button.cssVerticalAlign())
-		}
 
 	case HorizontalAlign:
-		if !button.setEnumProperty(tag, value, enumProperties[tag].values) {
+		view.Session().updateCSSProperty(view.htmlID()+"content", "justify-items", checkboxHorizontalAlignCSS(view))
-			return false
-		}
-		if button.created {
-			button.session.updateCSSProperty(button.htmlID()+"content", "justify-items", button.cssHorizontalAlign())
-		}
-
-	case CellVerticalAlign, CellHorizontalAlign, CellWidth, CellHeight:
-		return false
 
 	case AccentColor:
-		if !button.setColorProperty(AccentColor, value) {
+		updateInnerHTML(view.htmlID(), view.Session())
-			return false
-		}
-		if button.created {
-			updateInnerHTML(button.htmlID(), button.session)
-		}
 
 	default:
-		return button.viewsContainerData.set(tag, value)
+		viewsContainerPropertyChanged(view, tag)
+	}
 }
 
-	button.propertyChangedEvent(tag)
+func (button *checkboxData) setFunc(view View, tag PropertyName, value any) []PropertyName {
-	return true
-}
-
-func (button *checkboxData) Remove(tag string) {
-	button.remove(strings.ToLower(tag))
-}
-
-func (button *checkboxData) remove(tag string) {
 	switch tag {
 	case ClickEvent:
-		if !button.viewsContainerData.set(ClickEvent, checkboxClickListener) {
+		if button.viewsContainerData.setFunc(view, ClickEvent, value) != nil {
-			delete(button.properties, tag)
+			if value := view.getRaw(ClickEvent); value != nil {
+				if listeners, ok := value.([]func(View, MouseEvent)); ok {
+					listeners = append(listeners, checkboxClickListener)
+					view.setRaw(ClickEvent, listeners)
+					return []PropertyName{ClickEvent}
 				}
+			}
+
+			return button.viewsContainerData.setFunc(view, ClickEvent, checkboxClickListener)
+		}
+		return nil
 
 	case KeyDownEvent:
-		if !button.viewsContainerData.set(KeyDownEvent, checkboxKeyListener) {
+		if button.viewsContainerData.setFunc(view, KeyDownEvent, value) != nil {
-			delete(button.properties, tag)
+			if value := view.getRaw(KeyDownEvent); value != nil {
+				if listeners, ok := value.([]func(View, KeyEvent)); ok {
+					listeners = append(listeners, checkboxKeyListener)
+					view.setRaw(KeyDownEvent, listeners)
+					return []PropertyName{KeyDownEvent}
 				}
+			}
+
+			return button.viewsContainerData.setFunc(view, KeyDownEvent, checkboxKeyListener)
+		}
+		return nil
 
 	case CheckboxChangedEvent:
-		if len(button.checkedListeners) > 0 {
+		return setViewEventListener[Checkbox, bool](view, tag, value)
-			button.checkedListeners = []func(Checkbox, bool){}
-		}
 
 	case Checked:
-		oldChecked := button.checked()
+		return setBoolProperty(view, Checked, value)
-		delete(button.properties, tag)
+
-		if button.created && oldChecked {
+	case CellVerticalAlign, CellHorizontalAlign, CellWidth, CellHeight:
-			button.changedCheckboxState(false)
+		ErrorLogF(`"%s" property is not compatible with the BoundsProperty`, string(tag))
+		return nil
 	}
 
-	case CheckboxHorizontalAlign, CheckboxVerticalAlign:
+	return button.viewsContainerData.setFunc(view, tag, value)
-		delete(button.properties, tag)
-		if button.created {
-			htmlID := button.htmlID()
-			updateCSSStyle(htmlID, button.session)
-			updateInnerHTML(htmlID, button.session)
 }
 
-	case VerticalAlign:
+func (button *checkboxData) removeFunc(view View, tag PropertyName) []PropertyName {
-		delete(button.properties, tag)
+	switch tag {
-		if button.created {
+	case ClickEvent:
-			button.session.updateCSSProperty(button.htmlID()+"content", "align-items", button.cssVerticalAlign())
+		button.setRaw(ClickEvent, checkboxClickListener)
+		return []PropertyName{ClickEvent}
+
+	case KeyDownEvent:
+		button.setRaw(KeyDownEvent, checkboxKeyListener)
+		return []PropertyName{ClickEvent}
 	}
 
-	case HorizontalAlign:
+	return button.viewsContainerData.removeFunc(view, tag)
-		delete(button.properties, tag)
-		if button.created {
-			button.session.updateCSSProperty(button.htmlID()+"content", "justify-items", button.cssHorizontalAlign())
-		}
-
-	default:
-		button.viewsContainerData.remove(tag)
-		return
-	}
-	button.propertyChangedEvent(tag)
 }
 
 func (button *checkboxData) checked() bool {
@@ -201,8 +162,9 @@ func (button *checkboxData) checked() bool {
 	return checked
 }
 
+/*
 func (button *checkboxData) changedCheckboxState(state bool) {
-	for _, listener := range button.checkedListeners {
+	for _, listener := range GetCheckboxChangedListeners(button) {
 		listener(button, state)
 	}
 
@@ -212,8 +174,9 @@ func (button *checkboxData) changedCheckboxState(state bool) {
 	button.htmlCheckbox(buffer, state)
 	button.Session().updateInnerHTML(button.htmlID()+"checkbox", buffer.String())
 }
+*/
 
-func checkboxClickListener(view View) {
+func checkboxClickListener(view View, _ MouseEvent) {
 	view.Set(Checked, !IsCheckboxChecked(view))
 	BlurView(view)
 }
@@ -225,17 +188,6 @@ func checkboxKeyListener(view View, event KeyEvent) {
 	}
 }
 
-func (button *checkboxData) setChangedListener(value any) bool {
-	listeners, ok := valueToEventListeners[Checkbox, bool](value)
-	if !ok {
-		return false
-	} else if listeners == nil {
-		listeners = []func(Checkbox, bool){}
-	}
-	button.checkedListeners = listeners
-	return true
-}
-
 func (button *checkboxData) cssStyle(self View, builder cssBuilder) {
 	session := button.Session()
 	vAlign := GetCheckboxVerticalAlign(button)
@@ -265,7 +217,8 @@ func (button *checkboxData) cssStyle(self View, builder cssBuilder) {
 	button.viewsContainerData.cssStyle(self, builder)
 }
 
-func (button *checkboxData) htmlCheckbox(buffer *strings.Builder, checked bool) (int, int) {
+func checkboxHtml(button View, buffer *strings.Builder, checked bool) (int, int) {
+	//func (button *checkboxData) htmlCheckbox(buffer *strings.Builder, checked bool) (int, int) {
 	vAlign := GetCheckboxVerticalAlign(button)
 	hAlign := GetCheckboxHorizontalAlign(button)
 
@@ -317,7 +270,7 @@ func (button *checkboxData) htmlCheckbox(buffer *strings.Builder, checked bool)
 
 func (button *checkboxData) htmlSubviews(self View, buffer *strings.Builder) {
 
-	vCheckboxAlign, hCheckboxAlign := button.htmlCheckbox(buffer, IsCheckboxChecked(button))
+	vCheckboxAlign, hCheckboxAlign := checkboxHtml(button, buffer, IsCheckboxChecked(button))
 
 	buffer.WriteString(`<div id="`)
 	buffer.WriteString(button.htmlID())
@@ -335,11 +288,11 @@ func (button *checkboxData) htmlSubviews(self View, buffer *strings.Builder) {
 	}
 
 	buffer.WriteString(" align-items: ")
-	buffer.WriteString(button.cssVerticalAlign())
+	buffer.WriteString(checkboxVerticalAlignCSS(button))
 	buffer.WriteRune(';')
 
 	buffer.WriteString(" justify-items: ")
-	buffer.WriteString(button.cssHorizontalAlign())
+	buffer.WriteString(checkboxHorizontalAlignCSS(button))
 	buffer.WriteRune(';')
 
 	buffer.WriteString(`">`)
@@ -347,8 +300,8 @@ func (button *checkboxData) htmlSubviews(self View, buffer *strings.Builder) {
 	buffer.WriteString(`</div>`)
 }
 
-func (button *checkboxData) cssHorizontalAlign() string {
+func checkboxHorizontalAlignCSS(view View) string {
-	align := GetHorizontalAlign(button)
+	align := GetHorizontalAlign(view)
 	values := enumProperties[CellHorizontalAlign].cssValues
 	if align >= 0 && align < len(values) {
 		return values[align]
@@ -356,8 +309,8 @@ func (button *checkboxData) cssHorizontalAlign() string {
 	return values[0]
 }
 
-func (button *checkboxData) cssVerticalAlign() string {
+func checkboxVerticalAlignCSS(view View) string {
-	align := GetVerticalAlign(button)
+	align := GetVerticalAlign(view)
 	values := enumProperties[CellVerticalAlign].cssValues
 	if align >= 0 && align < len(values) {
 		return values[align]

colorPicker.go

@@ -25,7 +25,7 @@ const (
 	// `func(newColor rui.Color)`,
 	// `func(picker rui.ColorPicker)`,
 	// `func()`.
-	ColorChangedEvent = "color-changed"
+	ColorChangedEvent PropertyName = "color-changed"
 
 	// ColorPickerValue is the constant for "color-picker-value" property tag.
 	//
@@ -36,7 +36,7 @@ const (
 	//
 	// Internal type is `Color`, other types converted to it during assignment.
 	// See `Color` description for more details.
-	ColorPickerValue = "color-picker-value"
+	ColorPickerValue PropertyName = "color-picker-value"
 )
 
 // ColorPicker represent a ColorPicker view
@@ -46,8 +46,6 @@ type ColorPicker interface {
 
 type colorPickerData struct {
 	viewData
-	dataList
-	colorChangedListeners []func(ColorPicker, Color, Color)
 }
 
 // NewColorPicker create new ColorPicker object and return it
@@ -59,125 +57,69 @@ func NewColorPicker(session Session, params Params) ColorPicker {
 }
 
 func newColorPicker(session Session) View {
-	return NewColorPicker(session, nil)
+	return new(colorPickerData)
 }
 
 func (picker *colorPickerData) init(session Session) {
 	picker.viewData.init(session)
 	picker.tag = "ColorPicker"
 	picker.hasHtmlDisabled = true
-	picker.colorChangedListeners = []func(ColorPicker, Color, Color){}
 	picker.properties[Padding] = Px(0)
-	picker.dataListInit()
+	picker.normalize = normalizeColorPickerTag
+	picker.set = colorPickerSet
+	picker.changed = colorPickerPropertyChanged
 }
 
-func (picker *colorPickerData) String() string {
+func normalizeColorPickerTag(tag PropertyName) PropertyName {
-	return getViewString(picker, nil)
+	tag = defaultNormalize(tag)
-}
-
-func (picker *colorPickerData) normalizeTag(tag string) string {
-	tag = strings.ToLower(tag)
 	switch tag {
 	case Value, ColorTag:
 		return ColorPickerValue
 	}
 
-	return picker.normalizeDataListTag(tag)
+	return normalizeDataListTag(tag)
 }
 
-func (picker *colorPickerData) Remove(tag string) {
+func colorPickerSet(view View, tag PropertyName, value any) []PropertyName {
-	picker.remove(picker.normalizeTag(tag))
-}
-
-func (picker *colorPickerData) remove(tag string) {
 	switch tag {
 	case ColorChangedEvent:
-		if len(picker.colorChangedListeners) > 0 {
+		return setEventWithOldListener[ColorPicker, Color](view, tag, value)
-			picker.colorChangedListeners = []func(ColorPicker, Color, Color){}
-			picker.propertyChangedEvent(tag)
-		}
 
 	case ColorPickerValue:
-		oldColor := GetColorPickerValue(picker)
+		oldColor := GetColorPickerValue(view)
-		delete(picker.properties, ColorPickerValue)
+		result := setColorProperty(view, ColorPickerValue, value)
-		picker.colorChanged(oldColor)
+		if result != nil {
+			view.setRaw("old-color", oldColor)
+		}
+		return result
 
 	case DataList:
-		if len(picker.dataList.dataList) > 0 {
+		return setDataList(view, value, "")
-			picker.setDataList(picker, []string{}, true)
 	}
 
-	default:
+	return viewSet(view, tag, value)
-		picker.viewData.remove(tag)
-	}
-}
-
-func (picker *colorPickerData) Set(tag string, value any) bool {
-	return picker.set(picker.normalizeTag(tag), value)
-}
-
-func (picker *colorPickerData) set(tag string, value any) bool {
-	if value == nil {
-		picker.remove(tag)
-		return true
 }
 
+func colorPickerPropertyChanged(view View, tag PropertyName) {
 	switch tag {
-	case ColorChangedEvent:
-		listeners, ok := valueToEventWithOldListeners[ColorPicker, Color](value)
-		if !ok {
-			notCompatibleType(tag, value)
-			return false
-		} else if listeners == nil {
-			listeners = []func(ColorPicker, Color, Color){}
-		}
-		picker.colorChangedListeners = listeners
-		picker.propertyChangedEvent(tag)
-		return true
-
 	case ColorPickerValue:
-		oldColor := GetColorPickerValue(picker)
+		color := GetColorPickerValue(view)
-		if picker.setColorProperty(ColorPickerValue, value) {
+		view.Session().callFunc("setInputValue", view.htmlID(), color.rgbString())
-			picker.colorChanged(oldColor)
-			return true
-		}
 
-	case DataList:
+		if listeners := GetColorChangedListeners(view); len(listeners) > 0 {
-		return picker.setDataList(picker, value, picker.created)
+			oldColor := Color(0)
-
+			if value := view.getRaw("old-color"); value != nil {
-	default:
+				oldColor = value.(Color)
-		return picker.viewData.set(tag, value)
 			}
-	return false
+			for _, listener := range listeners {
-}
+				listener(view, color, oldColor)
-
-func (picker *colorPickerData) colorChanged(oldColor Color) {
-	if newColor := GetColorPickerValue(picker); oldColor != newColor {
-		if picker.created {
-			picker.session.callFunc("setInputValue", picker.htmlID(), newColor.rgbString())
-		}
-		for _, listener := range picker.colorChangedListeners {
-			listener(picker, newColor, oldColor)
-		}
-		picker.propertyChangedEvent(ColorTag)
 			}
 		}
 
-func (picker *colorPickerData) Get(tag string) any {
-	return picker.get(picker.normalizeTag(tag))
-}
-
-func (picker *colorPickerData) get(tag string) any {
-	switch tag {
-	case ColorChangedEvent:
-		return picker.colorChangedListeners
-
-	case DataList:
-		return picker.dataList.dataList
-
 	default:
-		return picker.viewData.get(tag)
+		viewPropertyChanged(view, tag)
 	}
+
 }
 
 func (picker *colorPickerData) htmlTag() string {
@@ -185,7 +127,10 @@ func (picker *colorPickerData) htmlTag() string {
 }
 
 func (picker *colorPickerData) htmlSubviews(self View, buffer *strings.Builder) {
-	picker.dataListHtmlSubviews(self, buffer)
+	dataListHtmlSubviews(self, buffer, func(text string, session Session) string {
+		text, _ = session.resolveConstants(text)
+		return text
+	})
 }
 
 func (picker *colorPickerData) htmlProperties(self View, buffer *strings.Builder) {
@@ -200,20 +145,23 @@ func (picker *colorPickerData) htmlProperties(self View, buffer *strings.Builder
 		buffer.WriteString(` onclick="stopEventPropagation(this, event)"`)
 	}
 
-	picker.dataListHtmlProperties(picker, buffer)
+	dataListHtmlProperties(picker, buffer)
 }
 
-func (picker *colorPickerData) handleCommand(self View, command string, data DataObject) bool {
+func (picker *colorPickerData) handleCommand(self View, command PropertyName, data DataObject) bool {
 	switch command {
 	case "textChanged":
 		if text, ok := data.PropertyValue("text"); ok {
-			oldColor := GetColorPickerValue(picker)
 			if color, ok := StringToColor(text); ok {
+				oldColor := GetColorPickerValue(picker)
 				picker.properties[ColorPickerValue] = color
 				if color != oldColor {
-					for _, listener := range picker.colorChangedListeners {
+					for _, listener := range GetColorChangedListeners(picker) {
 						listener(picker, color, oldColor)
 					}
+					if listener, ok := picker.changeListener[ColorPickerValue]; ok {
+						listener(picker, ColorPickerValue)
+					}
 				}
 			}
 		}
@@ -233,7 +181,7 @@ func GetColorPickerValue(view View, subviewID ...string) Color {
 		if value, ok := colorProperty(view, ColorPickerValue, view.Session()); ok {
 			return value
 		}
-		for _, tag := range []string{ColorPickerValue, Value, ColorTag} {
+		for _, tag := range []PropertyName{ColorPickerValue, Value, ColorTag} {
 			if value := valueFromStyle(view, tag); value != nil {
 				if result, ok := valueToColor(value, view.Session()); ok {
 					return result

columnLayout.go

@@ -2,7 +2,6 @@ package rui
 
 import (
 	"strconv"
-	"strings"
 )
 
 // Constants for [ColumnLayout] specific properties and events
@@ -18,7 +17,7 @@ const (
 	// Values:
 	// `0` or "0" - Use "column-width" to control how many columns will be created.
 	// >= `0` or >= "0" - Тhe number of columns into which the content is divided.
-	ColumnCount = "column-count"
+	ColumnCount PropertyName = "column-count"
 
 	// ColumnWidth is the constant for "column-width" property tag.
 	//
@@ -29,7 +28,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	ColumnWidth = "column-width"
+	ColumnWidth PropertyName = "column-width"
 
 	// ColumnGap is the constant for "column-gap" property tag.
 	//
@@ -40,7 +39,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	ColumnGap = "column-gap"
+	ColumnGap PropertyName = "column-gap"
 
 	// ColumnSeparator is the constant for "column-separator" property tag.
 	//
@@ -51,7 +50,7 @@ const (
 	//
 	// Internal type is `ColumnSeparatorProperty`, other types converted to it during assignment.
 	// See `ColumnSeparatorProperty` and `ViewBorder` description for more details.
-	ColumnSeparator = "column-separator"
+	ColumnSeparator PropertyName = "column-separator"
 
 	// ColumnSeparatorStyle is the constant for "column-separator-style" property tag.
 	//
@@ -66,7 +65,7 @@ const (
 	// `2`(`DashedLine`) or "dashed" - Dashed line as a separator.
 	// `3`(`DottedLine`) or "dotted" - Dotted line as a separator.
 	// `4`(`DoubleLine`) or "double" - Double line as a separator.
-	ColumnSeparatorStyle = "column-separator-style"
+	ColumnSeparatorStyle PropertyName = "column-separator-style"
 
 	// ColumnSeparatorWidth is the constant for "column-separator-width" property tag.
 	//
@@ -77,7 +76,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	ColumnSeparatorWidth = "column-separator-width"
+	ColumnSeparatorWidth PropertyName = "column-separator-width"
 
 	// ColumnSeparatorColor is the constant for "column-separator-color" property tag.
 	//
@@ -88,7 +87,7 @@ const (
 	//
 	// Internal type is `Color`, other types converted to it during assignment.
 	// See `Color` description for more details.
-	ColumnSeparatorColor = "column-separator-color"
+	ColumnSeparatorColor PropertyName = "column-separator-color"
 
 	// ColumnFill is the constant for "column-fill" property tag.
 	//
@@ -100,7 +99,7 @@ const (
 	// Values:
 	// `0`(`ColumnFillBalance`) or "balance" - Content is equally divided between columns.
 	// `1`(`ColumnFillAuto`) or "auto" - Columns are filled sequentially. Content takes up only the room it needs, possibly resulting in some columns remaining empty.
-	ColumnFill = "column-fill"
+	ColumnFill PropertyName = "column-fill"
 
 	// ColumnSpanAll is the constant for "column-span-all" property tag.
 	//
@@ -113,7 +112,7 @@ const (
 	// Values:
 	// `true` or `1` or "true", "yes", "on", "1" - View will span across all columns.
 	// `false` or `0` or "false", "no", "off", "0" - View will be a part of a column.
-	ColumnSpanAll = "column-span-all"
+	ColumnSpanAll PropertyName = "column-span-all"
 )
 
 // ColumnLayout represent a ColumnLayout view
@@ -134,22 +133,20 @@ func NewColumnLayout(session Session, params Params) ColumnLayout {
 }
 
 func newColumnLayout(session Session) View {
-	return NewColumnLayout(session, nil)
+	return new(columnLayoutData)
 }
 
 // Init initialize fields of ColumnLayout by default values
-func (ColumnLayout *columnLayoutData) init(session Session) {
+func (columnLayout *columnLayoutData) init(session Session) {
-	ColumnLayout.viewsContainerData.init(session)
+	columnLayout.viewsContainerData.init(session)
-	ColumnLayout.tag = "ColumnLayout"
+	columnLayout.tag = "ColumnLayout"
-	//ColumnLayout.systemClass = "ruiColumnLayout"
+	columnLayout.normalize = normalizeColumnLayoutTag
+	columnLayout.changed = columnLayoutPropertyChanged
+	//columnLayout.systemClass = "ruiColumnLayout"
 }
 
-func (columnLayout *columnLayoutData) String() string {
+func normalizeColumnLayoutTag(tag PropertyName) PropertyName {
-	return getViewString(columnLayout, nil)
+	tag = defaultNormalize(tag)
-}
-
-func (columnLayout *columnLayoutData) normalizeTag(tag string) string {
-	tag = strings.ToLower(tag)
 	switch tag {
 	case Gap:
 		return ColumnGap
@@ -157,63 +154,29 @@ func (columnLayout *columnLayoutData) normalizeTag(tag string) string {
 	return tag
 }
 
-func (columnLayout *columnLayoutData) Get(tag string) any {
+func columnLayoutPropertyChanged(view View, tag PropertyName) {
-	return columnLayout.get(columnLayout.normalizeTag(tag))
-}
-
-func (columnLayout *columnLayoutData) Remove(tag string) {
-	columnLayout.remove(columnLayout.normalizeTag(tag))
-}
-
-func (columnLayout *columnLayoutData) remove(tag string) {
-	columnLayout.viewsContainerData.remove(tag)
-	if columnLayout.created {
-		switch tag {
-		case ColumnCount, ColumnWidth, ColumnGap:
-			columnLayout.session.updateCSSProperty(columnLayout.htmlID(), tag, "")
-
-		case ColumnSeparator:
-			columnLayout.session.updateCSSProperty(columnLayout.htmlID(), "column-rule", "")
-		}
-	}
-}
-
-func (columnLayout *columnLayoutData) Set(tag string, value any) bool {
-	return columnLayout.set(columnLayout.normalizeTag(tag), value)
-}
-
-func (columnLayout *columnLayoutData) set(tag string, value any) bool {
-	if value == nil {
-		columnLayout.remove(tag)
-		return true
-	}
-
-	if !columnLayout.viewsContainerData.set(tag, value) {
-		return false
-	}
-
-	if columnLayout.created {
 	switch tag {
 	case ColumnSeparator:
 		css := ""
-			session := columnLayout.Session()
+		session := view.Session()
-			if val, ok := columnLayout.properties[ColumnSeparator]; ok {
+		if value := view.getRaw(ColumnSeparator); value != nil {
-				separator := val.(ColumnSeparatorProperty)
+			separator := value.(ColumnSeparatorProperty)
-				css = separator.cssValue(columnLayout.Session())
+			css = separator.cssValue(view.Session())
 		}
-			session.updateCSSProperty(columnLayout.htmlID(), "column-rule", css)
+		session.updateCSSProperty(view.htmlID(), "column-rule", css)
 
 	case ColumnCount:
-			session := columnLayout.Session()
+		session := view.Session()
-			if count, ok := intProperty(columnLayout, tag, session, 0); ok && count > 0 {
+		if count, ok := intProperty(view, tag, session, 0); ok && count > 0 {
-				session.updateCSSProperty(columnLayout.htmlID(), tag, strconv.Itoa(count))
+			session.updateCSSProperty(view.htmlID(), string(ColumnCount), strconv.Itoa(count))
 		} else {
-				session.updateCSSProperty(columnLayout.htmlID(), tag, "auto")
+			session.updateCSSProperty(view.htmlID(), string(ColumnCount), "auto")
 		}
+
+	default:
+		viewsContainerPropertyChanged(view, tag)
 	}
 }
-	return true
-}
 
 // GetColumnCount returns int value which specifies number of columns into which the content of
 // ColumnLayout is break. If the return value is 0 then the number of columns is calculated

columnSeparator.go

@@ -18,14 +18,14 @@ type ColumnSeparatorProperty interface {
 }
 
 type columnSeparatorProperty struct {
-	propertyList
+	dataProperty
 }
 
 func newColumnSeparatorProperty(value any) ColumnSeparatorProperty {
 
 	if value == nil {
 		separator := new(columnSeparatorProperty)
-		separator.properties = map[string]any{}
+		separator.init()
 		return separator
 	}
 
@@ -35,17 +35,18 @@ func newColumnSeparatorProperty(value any) ColumnSeparatorProperty {
 
 	case DataObject:
 		separator := new(columnSeparatorProperty)
-		separator.properties = map[string]any{}
+		separator.init()
-		for _, tag := range []string{Style, Width, ColorTag} {
+		for _, tag := range []PropertyName{Style, Width, ColorTag} {
-			if val, ok := value.PropertyValue(tag); ok && val != "" {
+			if val, ok := value.PropertyValue(string(tag)); ok && val != "" {
-				separator.set(tag, value)
+				propertiesSet(separator, tag, value)
 			}
 		}
 		return separator
 
 	case ViewBorder:
 		separator := new(columnSeparatorProperty)
-		separator.properties = map[string]any{
+		separator.init()
+		separator.properties = map[PropertyName]any{
 			Style:    value.Style,
 			Width:    value.Width,
 			ColorTag: value.Color,
@@ -67,9 +68,9 @@ func newColumnSeparatorProperty(value any) ColumnSeparatorProperty {
 // "width" (Width). Determines the line thickness (SizeUnit).
 func NewColumnSeparator(params Params) ColumnSeparatorProperty {
 	separator := new(columnSeparatorProperty)
-	separator.properties = map[string]any{}
+	separator.init()
 	if params != nil {
-		for _, tag := range []string{Style, Width, ColorTag} {
+		for _, tag := range []PropertyName{Style, Width, ColorTag} {
 			if value, ok := params[tag]; ok && value != nil {
 				separator.Set(tag, value)
 			}
@@ -78,8 +79,14 @@ func NewColumnSeparator(params Params) ColumnSeparatorProperty {
 	return separator
 }
 
-func (separator *columnSeparatorProperty) normalizeTag(tag string) string {
+func (separator *columnSeparatorProperty) init() {
-	tag = strings.ToLower(tag)
+	separator.dataProperty.init()
+	separator.normalize = normalizeVolumnSeparatorTag
+	separator.supportedProperties = []PropertyName{Style, Width, ColorTag}
+}
+
+func normalizeVolumnSeparatorTag(tag PropertyName) PropertyName {
+	tag = defaultNormalize(tag)
 	switch tag {
 	case ColumnSeparatorStyle, "separator-style":
 		return Style
@@ -97,12 +104,12 @@ func (separator *columnSeparatorProperty) normalizeTag(tag string) string {
 func (separator *columnSeparatorProperty) writeString(buffer *strings.Builder, indent string) {
 	buffer.WriteString("_{ ")
 	comma := false
-	for _, tag := range []string{Style, Width, ColorTag} {
+	for _, tag := range []PropertyName{Style, Width, ColorTag} {
 		if value, ok := separator.properties[tag]; ok {
 			if comma {
 				buffer.WriteString(", ")
 			}
-			buffer.WriteString(tag)
+			buffer.WriteString(string(tag))
 			buffer.WriteString(" = ")
 			writePropertyValue(buffer, BorderStyle, value, indent)
 			comma = true
@@ -116,47 +123,12 @@ func (separator *columnSeparatorProperty) String() string {
 	return runStringWriter(separator)
 }
 
-func (separator *columnSeparatorProperty) Remove(tag string) {
+func getColumnSeparatorProperty(properties Properties) ColumnSeparatorProperty {
-
+	if val := properties.getRaw(ColumnSeparator); val != nil {
-	switch tag = separator.normalizeTag(tag); tag {
+		if separator, ok := val.(ColumnSeparatorProperty); ok {
-	case Style, Width, ColorTag:
+			return separator
-		delete(separator.properties, tag)
-
-	default:
-		ErrorLogF(`"%s" property is not compatible with the ColumnSeparatorProperty`, tag)
 		}
 	}
-
-func (separator *columnSeparatorProperty) Set(tag string, value any) bool {
-	tag = separator.normalizeTag(tag)
-
-	if value == nil {
-		separator.remove(tag)
-		return true
-	}
-
-	switch tag {
-	case Style:
-		return separator.setEnumProperty(Style, value, enumProperties[BorderStyle].values)
-
-	case Width:
-		return separator.setSizeProperty(Width, value)
-
-	case ColorTag:
-		return separator.setColorProperty(ColorTag, value)
-	}
-
-	ErrorLogF(`"%s" property is not compatible with the ColumnSeparatorProperty`, tag)
-	return false
-}
-
-func (separator *columnSeparatorProperty) Get(tag string) any {
-	tag = separator.normalizeTag(tag)
-
-	if result, ok := separator.properties[tag]; ok {
-		return result
-	}
-
 	return nil
 }
 

customView.go

@@ -36,6 +36,9 @@ func InitCustomView(customView CustomView, tag string, session Session, params P
 	return true
 }
 
+func (customView *CustomViewData) init(session Session) {
+}
+
 // SuperView returns a super view
 func (customView *CustomViewData) SuperView() View {
 	return customView.superView
@@ -57,29 +60,36 @@ func (customView *CustomViewData) setTag(tag string) {
 
 // Get returns a value of the property with name defined by the argument.
 // The type of return value depends on the property. If the property is not set then nil is returned.
-func (customView *CustomViewData) Get(tag string) any {
+func (customView *CustomViewData) Get(tag PropertyName) any {
 	return customView.superView.Get(tag)
 }
 
-func (customView *CustomViewData) getRaw(tag string) any {
+func (customView *CustomViewData) getRaw(tag PropertyName) any {
 	return customView.superView.getRaw(tag)
 }
 
-func (customView *CustomViewData) setRaw(tag string, value any) {
+func (customView *CustomViewData) setRaw(tag PropertyName, value any) {
 	customView.superView.setRaw(tag, value)
 }
 
+func (customView *CustomViewData) setContent(value any) bool {
+	if container, ok := customView.superView.(ViewsContainer); ok {
+		return container.setContent(value)
+	}
+	return false
+}
+
 // Set sets the value (second argument) of the property with name defined by the first argument.
 // Return "true" if the value has been set, in the opposite case "false" are returned and
 // a description of the error is written to the log
-func (customView *CustomViewData) Set(tag string, value any) bool {
+func (customView *CustomViewData) Set(tag PropertyName, value any) bool {
 	return customView.superView.Set(tag, value)
 }
 
 // SetAnimated sets the value (second argument) of the property with name defined by the first argument.
 // Return "true" if the value has been set, in the opposite case "false" are returned and
 // a description of the error is written to the log
-func (customView *CustomViewData) SetAnimated(tag string, value any, animation Animation) bool {
+func (customView *CustomViewData) SetAnimated(tag PropertyName, value any, animation Animation) bool {
 	return customView.superView.SetAnimated(tag, value, animation)
 }
 
@@ -88,20 +98,24 @@ func (customView *CustomViewData) SetParams(params Params) bool {
 }
 
 // SetChangeListener set the function to track the change of the View property
-func (customView *CustomViewData) SetChangeListener(tag string, listener func(View, string)) {
+func (customView *CustomViewData) SetChangeListener(tag PropertyName, listener func(View, PropertyName)) {
 	customView.superView.SetChangeListener(tag, listener)
 }
 
 // Remove removes the property with name defined by the argument
-func (customView *CustomViewData) Remove(tag string) {
+func (customView *CustomViewData) Remove(tag PropertyName) {
 	customView.superView.Remove(tag)
 }
 
 // AllTags returns an array of the set properties
-func (customView *CustomViewData) AllTags() []string {
+func (customView *CustomViewData) AllTags() []PropertyName {
 	return customView.superView.AllTags()
 }
 
+func (customView *CustomViewData) empty() bool {
+	return customView.superView.empty()
+}
+
 // Clear removes all properties
 func (customView *CustomViewData) Clear() {
 	customView.superView.Clear()
@@ -182,7 +196,7 @@ func (customView *CustomViewData) onItemResize(self View, index string, x, y, wi
 	customView.superView.onItemResize(customView.superView, index, x, y, width, height)
 }
 
-func (customView *CustomViewData) handleCommand(self View, command string, data DataObject) bool {
+func (customView *CustomViewData) handleCommand(self View, command PropertyName, data DataObject) bool {
 	return customView.superView.handleCommand(customView.superView, command, data)
 }
 
@@ -210,6 +224,10 @@ func (customView *CustomViewData) htmlProperties(self View, buffer *strings.Buil
 	customView.superView.htmlProperties(customView.superView, buffer)
 }
 
+func (customView *CustomViewData) htmlDisabledProperty() bool {
+	return customView.superView.htmlDisabledProperty()
+}
+
 func (customView *CustomViewData) cssStyle(self View, builder cssBuilder) {
 	customView.superView.cssStyle(customView.superView, builder)
 }
@@ -274,9 +292,9 @@ func (customView *CustomViewData) ViewIndex(view View) int {
 	return -1
 }
 
-func (customView *CustomViewData) exscludeTags() []string {
+func (customView *CustomViewData) exscludeTags() []PropertyName {
 	if customView.superView != nil {
-		exsclude := []string{}
+		exsclude := []PropertyName{}
 		for tag, value := range customView.defaultParams {
 			if value == customView.superView.getRaw(tag) {
 				exsclude = append(exsclude, tag)
@@ -290,7 +308,10 @@ func (customView *CustomViewData) exscludeTags() []string {
 // String convert internal representation of a [CustomViewData] into a string.
 func (customView *CustomViewData) String() string {
 	if customView.superView != nil {
-		return getViewString(customView, customView.exscludeTags())
+		buffer := allocStringBuilder()
+		defer freeStringBuilder(buffer)
+		writeViewStyle(customView.tag, customView, buffer, "", customView.exscludeTags())
+		return buffer.String()
 	}
 	return customView.tag + " { }"
 }
@@ -302,7 +323,7 @@ func (customView *CustomViewData) setScroll(x, y, width, height float64) {
 }
 
 // Transition returns the transition animation of the property(tag). Returns nil is there is no transition animation.
-func (customView *CustomViewData) Transition(tag string) Animation {
+func (customView *CustomViewData) Transition(tag PropertyName) Animation {
 	if customView.superView != nil {
 		return customView.superView.Transition(tag)
 	}
@@ -310,17 +331,17 @@ func (customView *CustomViewData) Transition(tag string) Animation {
 }
 
 // Transitions returns a map of transition animations. The result is always non-nil.
-func (customView *CustomViewData) Transitions() map[string]Animation {
+func (customView *CustomViewData) Transitions() map[PropertyName]Animation {
 	if customView.superView != nil {
 		return customView.superView.Transitions()
 	}
-	return map[string]Animation{}
+	return map[PropertyName]Animation{}
 }
 
 // SetTransition sets the transition animation for the property if "animation" argument is not nil, and
 // removes the transition animation of the property if "animation" argument  is nil.
 // The "tag" argument is the property name.
-func (customView *CustomViewData) SetTransition(tag string, animation Animation) {
+func (customView *CustomViewData) SetTransition(tag PropertyName, animation Animation) {
 	if customView.superView != nil {
 		customView.superView.SetTransition(tag, animation)
 	}

data.go

@@ -212,12 +212,12 @@ func (object *dataObject) ToParams() Params {
 		switch node.Type() {
 		case TextNode:
 			if text := node.Text(); text != "" {
-				params[node.Tag()] = text
+				params[PropertyName(node.Tag())] = text
 			}
 
 		case ObjectNode:
 			if obj := node.Object(); obj != nil {
-				params[node.Tag()] = node.Object()
+				params[PropertyName(node.Tag())] = node.Object()
 			}
 
 		case ArrayNode:
@@ -234,7 +234,7 @@ func (object *dataObject) ToParams() Params {
 				}
 			}
 			if len(array) > 0 {
-				params[node.Tag()] = array
+				params[PropertyName(node.Tag())] = array
 			}
 		}
 	}

dataList.go

@@ -1,6 +1,11 @@
 package rui
 
-import "strings"
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+)
 
 const (
 	// DataList is the constant for "data-list" property tag.
@@ -98,23 +103,14 @@ const (
 	// `[]Color` - An array of color values which will be converted to a string array.
 	// `[]SizeUnit` - an array of size unit values which will be converted to a string array.
 	// `[]any` - this array must contain only types which were listed in Types section.
-	DataList = "data-list"
+	DataList PropertyName = "data-list"
 )
 
-type dataList struct {
+func dataListID(view View) string {
-	dataList     []string
-	dataListHtml bool
-}
-
-func (list *dataList) dataListInit() {
-	list.dataList = []string{}
-}
-
-func (list *dataList) dataListID(view View) string {
 	return view.htmlID() + "-datalist"
 }
 
-func (list *dataList) normalizeDataListTag(tag string) string {
+func normalizeDataListTag(tag PropertyName) PropertyName {
 	switch tag {
 	case "datalist":
 		return DataList
@@ -123,6 +119,210 @@ func (list *dataList) normalizeDataListTag(tag string) string {
 	return tag
 }
 
+func setDataList(properties Properties, value any, dateTimeFormat string) []PropertyName {
+	if items, ok := anyToStringArray(value, timeFormat); ok {
+		properties.setRaw(DataList, items)
+		return []PropertyName{DataList}
+	}
+
+	notCompatibleType(DataList, value)
+	return nil
+}
+
+func anyToStringArray(value any, dateTimeFormat string) ([]string, bool) {
+
+	switch value := value.(type) {
+	case string:
+		return []string{value}, true
+
+	case []string:
+		return value, true
+
+	case []DataValue:
+		items := make([]string, 0, len(value))
+		for _, val := range value {
+			if !val.IsObject() {
+				items = append(items, val.Value())
+			}
+		}
+		return items, true
+
+	case []fmt.Stringer:
+		items := make([]string, len(value))
+		for i, str := range value {
+			items[i] = str.String()
+		}
+		return items, true
+
+	case []Color:
+		items := make([]string, len(value))
+		for i, str := range value {
+			items[i] = str.String()
+		}
+		return items, true
+
+	case []SizeUnit:
+		items := make([]string, len(value))
+		for i, str := range value {
+			items[i] = str.String()
+		}
+		return items, true
+
+	case []AngleUnit:
+		items := make([]string, len(value))
+		for i, str := range value {
+			items[i] = str.String()
+		}
+		return items, true
+
+	case []float32:
+		items := make([]string, len(value))
+		for i, val := range value {
+			items[i] = fmt.Sprintf("%g", float64(val))
+		}
+		return items, true
+
+	case []float64:
+		items := make([]string, len(value))
+		for i, val := range value {
+			items[i] = fmt.Sprintf("%g", val)
+		}
+		return items, true
+
+	case []int:
+		return intArrayToStringArray(value), true
+
+	case []uint:
+		return intArrayToStringArray(value), true
+
+	case []int8:
+		return intArrayToStringArray(value), true
+
+	case []uint8:
+		return intArrayToStringArray(value), true
+
+	case []int16:
+		return intArrayToStringArray(value), true
+
+	case []uint16:
+		return intArrayToStringArray(value), true
+
+	case []int32:
+		return intArrayToStringArray(value), true
+
+	case []uint32:
+		return intArrayToStringArray(value), true
+
+	case []int64:
+		return intArrayToStringArray(value), true
+
+	case []uint64:
+		return intArrayToStringArray(value), true
+
+	case []bool:
+		items := make([]string, len(value))
+		for i, val := range value {
+			if val {
+				items[i] = "true"
+			} else {
+				items[i] = "false"
+			}
+		}
+		return items, true
+
+	case []time.Time:
+		if dateTimeFormat == "" {
+			dateTimeFormat = dateFormat + " " + timeFormat
+		}
+
+		items := make([]string, len(value))
+		for i, val := range value {
+			items[i] = val.Format(dateTimeFormat)
+		}
+		return items, true
+
+	case []any:
+		items := make([]string, 0, len(value))
+		for _, v := range value {
+			switch val := v.(type) {
+			case string:
+				items = append(items, val)
+
+			case fmt.Stringer:
+				items = append(items, val.String())
+
+			case bool:
+				if val {
+					items = append(items, "true")
+				} else {
+					items = append(items, "false")
+				}
+
+			case float32:
+				items = append(items, fmt.Sprintf("%g", float64(val)))
+
+			case float64:
+				items = append(items, fmt.Sprintf("%g", val))
+
+			case rune:
+				items = append(items, string(val))
+
+			default:
+				if n, ok := isInt(v); ok {
+					items = append(items, strconv.Itoa(n))
+				} else {
+					return []string{}, false
+				}
+			}
+		}
+
+		return items, true
+	}
+
+	return []string{}, false
+}
+
+func getDataListProperty(properties Properties) []string {
+	if value := properties.getRaw(DataList); value != nil {
+		if items, ok := value.([]string); ok {
+			return items
+		}
+	}
+	return nil
+}
+
+func dataListHtmlSubviews(view View, buffer *strings.Builder, normalizeItem func(text string, session Session) string) {
+	if items := getDataListProperty(view); len(items) > 0 {
+		session := view.Session()
+		buffer.WriteString(`<datalist id="`)
+		buffer.WriteString(dataListID(view))
+		buffer.WriteString(`">`)
+		for _, text := range items {
+			text = normalizeItem(text, session)
+
+			if strings.ContainsRune(text, '"') {
+				text = strings.ReplaceAll(text, `"`, `&#34;`)
+			}
+			if strings.ContainsRune(text, '\n') {
+				text = strings.ReplaceAll(text, "\n", `\n`)
+			}
+			buffer.WriteString(`<option value="`)
+			buffer.WriteString(text)
+			buffer.WriteString(`"></option>`)
+		}
+		buffer.WriteString(`</datalist>`)
+	}
+}
+
+func dataListHtmlProperties(view View, buffer *strings.Builder) {
+	if len(getDataListProperty(view)) > 0 {
+		buffer.WriteString(` list="`)
+		buffer.WriteString(dataListID(view))
+		buffer.WriteString(`"`)
+	}
+}
+
+/*
 func (list *dataList) setDataList(view View, value any, created bool) bool {
 	items, ok := anyToStringArray(value)
 	if !ok {
@@ -133,7 +333,7 @@ func (list *dataList) setDataList(view View, value any, created bool) bool {
 	list.dataList = items
 	if created {
 		session := view.Session()
-		dataListID := list.dataListID(view)
+		dataListID := dataListID(view)
 		buffer := allocStringBuilder()
 		defer freeStringBuilder(buffer)
 
@@ -162,7 +362,7 @@ func (list *dataList) dataListHtmlSubviews(view View, buffer *strings.Builder) {
 
 func (list *dataList) dataListHtmlCode(view View, buffer *strings.Builder) {
 	buffer.WriteString(`<datalist id="`)
-	buffer.WriteString(list.dataListID(view))
+	buffer.WriteString(dataListID(view))
 	buffer.WriteString(`">`)
 	list.dataListItemsHtml(buffer)
 	buffer.WriteString(`</datalist>`)
@@ -185,10 +385,11 @@ func (list *dataList) dataListItemsHtml(buffer *strings.Builder) {
 func (list *dataList) dataListHtmlProperties(view View, buffer *strings.Builder) {
 	if len(list.dataList) > 0 {
 		buffer.WriteString(` list="`)
-		buffer.WriteString(list.dataListID(view))
+		buffer.WriteString(dataListID(view))
 		buffer.WriteString(`"`)
 	}
 }
+*/
 
 // GetDataList returns the data list of an editor.
 // If the second argument (subviewID) is not specified or it is "" then a value from the first argument (view) is returned.
@@ -198,11 +399,7 @@ func GetDataList(view View, subviewID ...string) []string {
 	}
 
 	if view != nil {
-		if value := view.Get(DataList); value != nil {
+		return getDataListProperty(view)
-			if list, ok := value.([]string); ok {
-				return list
-			}
-		}
 	}
 
 	return []string{}

datePicker.go

@@ -27,7 +27,7 @@ const (
 	// `func(newDate time.Time)`,
 	// `func(picker rui.DatePicker)`,
 	// `func()`.
-	DateChangedEvent = "date-changed"
+	DateChangedEvent PropertyName = "date-changed"
 
 	// DatePickerMin is the constant for "date-picker-min" property tag.
 	//
@@ -50,7 +50,7 @@ const (
 	// "MM/DD/YYYY" - "01/02/2024".
 	// "MM/DD/YY" - "01/02/24".
 	// "MMDDYY" - "010224".
-	DatePickerMin = "date-picker-min"
+	DatePickerMin PropertyName = "date-picker-min"
 
 	// DatePickerMax is the constant for "date-picker-max" property tag.
 	//
@@ -73,7 +73,7 @@ const (
 	// "MM/DD/YYYY" - "01/02/2024".
 	// "MM/DD/YY" - "01/02/24".
 	// "MMDDYY" - "010224".
-	DatePickerMax = "date-picker-max"
+	DatePickerMax PropertyName = "date-picker-max"
 
 	// DatePickerStep is the constant for "date-picker-step" property tag.
 	//
@@ -84,7 +84,7 @@ const (
 	//
 	// Values:
 	// >= `0` or >= "0" - Step value in days used to increment or decrement date.
-	DatePickerStep = "date-picker-step"
+	DatePickerStep PropertyName = "date-picker-step"
 
 	// DatePickerValue is the constant for "date-picker-value" property tag.
 	//
@@ -107,7 +107,7 @@ const (
 	// "MM/DD/YYYY" - "01/02/2024".
 	// "MM/DD/YY" - "01/02/24".
 	// "MMDDYY" - "010224".
-	DatePickerValue = "date-picker-value"
+	DatePickerValue PropertyName = "date-picker-value"
 
 	dateFormat = "2006-01-02"
 )
@@ -119,8 +119,6 @@ type DatePicker interface {
 
 type datePickerData struct {
 	viewData
-	dataList
-	dateChangedListeners []func(DatePicker, time.Time, time.Time)
 }
 
 // NewDatePicker create new DatePicker object and return it
@@ -132,114 +130,36 @@ func NewDatePicker(session Session, params Params) DatePicker {
 }
 
 func newDatePicker(session Session) View {
-	return NewDatePicker(session, nil)
+	return new(datePickerData) // NewDatePicker(session, nil)
 }
 
 func (picker *datePickerData) init(session Session) {
 	picker.viewData.init(session)
 	picker.tag = "DatePicker"
 	picker.hasHtmlDisabled = true
-	picker.dateChangedListeners = []func(DatePicker, time.Time, time.Time){}
+	picker.normalize = normalizeDatePickerTag
-	picker.dataListInit()
+	picker.set = datePickerSet
-}
+	picker.changed = datePickerPropertyChanged
-
-func (picker *datePickerData) String() string {
-	return getViewString(picker, nil)
 }
 
 func (picker *datePickerData) Focusable() bool {
 	return true
 }
 
-func (picker *datePickerData) normalizeTag(tag string) string {
+func normalizeDatePickerTag(tag PropertyName) PropertyName {
-	tag = strings.ToLower(tag)
+	tag = defaultNormalize(tag)
 	switch tag {
 	case Type, Min, Max, Step, Value:
 		return "date-picker-" + tag
 	}
 
-	return tag
+	return normalizeDataListTag(tag)
 }
 
-func (picker *datePickerData) Remove(tag string) {
+func stringToDate(value string) (time.Time, bool) {
-	picker.remove(picker.normalizeTag(tag))
-}
-
-func (picker *datePickerData) remove(tag string) {
-	switch tag {
-	case DateChangedEvent:
-		if len(picker.dateChangedListeners) > 0 {
-			picker.dateChangedListeners = []func(DatePicker, time.Time, time.Time){}
-			picker.propertyChangedEvent(tag)
-		}
-		return
-
-	case DatePickerMin:
-		delete(picker.properties, DatePickerMin)
-		if picker.created {
-			picker.session.removeProperty(picker.htmlID(), Min)
-		}
-
-	case DatePickerMax:
-		delete(picker.properties, DatePickerMax)
-		if picker.created {
-			picker.session.removeProperty(picker.htmlID(), Max)
-		}
-
-	case DatePickerStep:
-		delete(picker.properties, DatePickerStep)
-		if picker.created {
-			picker.session.removeProperty(picker.htmlID(), Step)
-		}
-
-	case DatePickerValue:
-		if _, ok := picker.properties[DatePickerValue]; ok {
-			oldDate := GetDatePickerValue(picker)
-			delete(picker.properties, DatePickerValue)
-			date := GetDatePickerValue(picker)
-			if picker.created {
-				picker.session.callFunc("setInputValue", picker.htmlID(), date.Format(dateFormat))
-			}
-			for _, listener := range picker.dateChangedListeners {
-				listener(picker, date, oldDate)
-			}
-		} else {
-			return
-		}
-
-	case DataList:
-		if len(picker.dataList.dataList) > 0 {
-			picker.setDataList(picker, []string{}, true)
-		}
-
-	default:
-		picker.viewData.remove(tag)
-		return
-	}
-	picker.propertyChangedEvent(tag)
-}
-
-func (picker *datePickerData) Set(tag string, value any) bool {
-	return picker.set(picker.normalizeTag(tag), value)
-}
-
-func (picker *datePickerData) set(tag string, value any) bool {
-	if value == nil {
-		picker.remove(tag)
-		return true
-	}
-
-	setTimeValue := func(tag string) (time.Time, bool) {
-		switch value := value.(type) {
-		case time.Time:
-			picker.properties[tag] = value
-			return value, true
-
-		case string:
-			if text, ok := picker.Session().resolveConstants(value); ok {
 	format := "20060102"
-				if strings.ContainsRune(text, '-') {
+	if strings.ContainsRune(value, '-') {
-					if part := strings.Split(text, "-"); len(part) == 3 {
+		if part := strings.Split(value, "-"); len(part) == 3 {
 			if part[0] != "" && part[0][0] > '9' {
 				if len(part[2]) == 2 {
 					format = "Jan-02-06"
@@ -252,128 +172,122 @@ func (picker *datePickerData) set(tag string, value any) bool {
 				format = "2006-01-02"
 			}
 		}
-				} else if strings.ContainsRune(text, ' ') {
+	} else if strings.ContainsRune(value, ' ') {
-					if part := strings.Split(text, " "); len(part) == 3 {
+		if part := strings.Split(value, " "); len(part) == 3 {
 			if part[0] != "" && part[0][0] > '9' {
 				format = "January 02, 2006"
 			} else {
 				format = "02 January 2006"
 			}
 		}
-				} else if strings.ContainsRune(text, '/') {
+	} else if strings.ContainsRune(value, '/') {
-					if part := strings.Split(text, "/"); len(part) == 3 {
+		if part := strings.Split(value, "/"); len(part) == 3 {
 			if len(part[2]) == 2 {
 				format = "01/02/06"
 			} else {
 				format = "01/02/2006"
 			}
 		}
-				} else if len(text) == 6 {
+	} else if len(value) == 6 {
 		format = "010206"
 	}
 
-				if date, err := time.Parse(format, text); err == nil {
+	if date, err := time.Parse(format, value); err == nil {
-					picker.properties[tag] = value
 		return date, true
 	}
-			}
-		}
-
-		notCompatibleType(tag, value)
 	return time.Now(), false
 }
 
+func datePickerSet(view View, tag PropertyName, value any) []PropertyName {
+
+	setDateValue := func(tag PropertyName) []PropertyName {
+		switch value := value.(type) {
+		case time.Time:
+			view.setRaw(tag, value)
+			return []PropertyName{tag}
+
+		case string:
+			if isConstantName(value) {
+				view.setRaw(tag, value)
+				return []PropertyName{tag}
+			}
+
+			if date, ok := stringToDate(value); ok {
+				view.setRaw(tag, date)
+				return []PropertyName{tag}
+			}
+		}
+
+		notCompatibleType(tag, value)
+		return nil
+	}
+
 	switch tag {
+	case DatePickerMin, DatePickerMax:
+		return setDateValue(tag)
+
+	case DatePickerStep:
+		return setIntProperty(view, DatePickerStep, value)
+
+	case DatePickerValue:
+		view.setRaw("old-date", GetDatePickerValue(view))
+		return setDateValue(tag)
+
+	case DateChangedEvent:
+		return setEventWithOldListener[DatePicker, time.Time](view, tag, value)
+
+	case DataList:
+		return setDataList(view, value, dateFormat)
+	}
+
+	return viewSet(view, tag, value)
+}
+
+func datePickerPropertyChanged(view View, tag PropertyName) {
+
+	session := view.Session()
+
+	switch tag {
+
 	case DatePickerMin:
-		old, oldOK := getDateProperty(picker, DatePickerMin, Min)
+		if date, ok := GetDatePickerMin(view); ok {
-		if date, ok := setTimeValue(DatePickerMin); ok {
+			session.updateProperty(view.htmlID(), "min", date.Format(dateFormat))
-			if !oldOK || date != old {
+		} else {
-				if picker.created {
+			session.removeProperty(view.htmlID(), "min")
-					picker.session.updateProperty(picker.htmlID(), Min, date.Format(dateFormat))
-				}
-				picker.propertyChangedEvent(tag)
-			}
-			return true
 		}
 
 	case DatePickerMax:
-		old, oldOK := getDateProperty(picker, DatePickerMax, Max)
+		if date, ok := GetDatePickerMax(view); ok {
-		if date, ok := setTimeValue(DatePickerMax); ok {
+			session.updateProperty(view.htmlID(), "max", date.Format(dateFormat))
-			if !oldOK || date != old {
+		} else {
-				if picker.created {
+			session.removeProperty(view.htmlID(), "max")
-					picker.session.updateProperty(picker.htmlID(), Max, date.Format(dateFormat))
-				}
-				picker.propertyChangedEvent(tag)
-			}
-			return true
 		}
 
 	case DatePickerStep:
-		oldStep := GetDatePickerStep(picker)
+		if step := GetDatePickerStep(view); step > 0 {
-		if picker.setIntProperty(DatePickerStep, value) {
+			session.updateProperty(view.htmlID(), "step", strconv.Itoa(step))
-			if step := GetDatePickerStep(picker); oldStep != step {
-				if picker.created {
-					if step > 0 {
-						picker.session.updateProperty(picker.htmlID(), Step, strconv.Itoa(step))
 		} else {
-						picker.session.removeProperty(picker.htmlID(), Step)
+			session.removeProperty(view.htmlID(), "step")
-					}
-				}
-				picker.propertyChangedEvent(tag)
-			}
-			return true
 		}
 
 	case DatePickerValue:
-		oldDate := GetDatePickerValue(picker)
+		date := GetDatePickerValue(view)
-		if date, ok := setTimeValue(DatePickerValue); ok {
+		session.callFunc("setInputValue", view.htmlID(), date.Format(dateFormat))
-			if date != oldDate {
-				if picker.created {
-					picker.session.callFunc("setInputValue", picker.htmlID(), date.Format(dateFormat))
-				}
-				for _, listener := range picker.dateChangedListeners {
-					listener(picker, date, oldDate)
-				}
-				picker.propertyChangedEvent(tag)
-			}
-			return true
-		}
 
-	case DateChangedEvent:
+		if listeners := GetDateChangedListeners(view); len(listeners) > 0 {
-		listeners, ok := valueToEventWithOldListeners[DatePicker, time.Time](value)
+			oldDate := time.Now()
-		if !ok {
+			if value := view.getRaw("old-date"); value != nil {
-			notCompatibleType(tag, value)
+				if date, ok := value.(time.Time); ok {
-			return false
+					oldDate = date
-		} else if listeners == nil {
+				}
-			listeners = []func(DatePicker, time.Time, time.Time){}
+			}
+			for _, listener := range listeners {
+				listener(view, date, oldDate)
+			}
 		}
-		picker.dateChangedListeners = listeners
-		picker.propertyChangedEvent(tag)
-		return true
-
-	case DataList:
-		return picker.setDataList(picker, value, picker.created)
 
 	default:
-		return picker.viewData.set(tag, value)
+		viewPropertyChanged(view, tag)
-	}
-	return false
-}
-
-func (picker *datePickerData) Get(tag string) any {
-	return picker.get(picker.normalizeTag(tag))
-}
-
-func (picker *datePickerData) get(tag string) any {
-	switch tag {
-	case DateChangedEvent:
-		return picker.dateChangedListeners
-
-	case DataList:
-		return picker.dataList.dataList
-
-	default:
-		return picker.viewData.get(tag)
 	}
 }
 
@@ -382,7 +296,13 @@ func (picker *datePickerData) htmlTag() string {
 }
 
 func (picker *datePickerData) htmlSubviews(self View, buffer *strings.Builder) {
-	picker.dataListHtmlSubviews(self, buffer)
+	dataListHtmlSubviews(self, buffer, func(text string, session Session) string {
+		text, _ = session.resolveConstants(text)
+		if date, ok := stringToDate(text); ok {
+			return date.Format(dateFormat)
+		}
+		return text
+	})
 }
 
 func (picker *datePickerData) htmlProperties(self View, buffer *strings.Builder) {
@@ -417,10 +337,10 @@ func (picker *datePickerData) htmlProperties(self View, buffer *strings.Builder)
 		buffer.WriteString(` onclick="stopEventPropagation(this, event)"`)
 	}
 
-	picker.dataListHtmlProperties(picker, buffer)
+	dataListHtmlProperties(picker, buffer)
 }
 
-func (picker *datePickerData) handleCommand(self View, command string, data DataObject) bool {
+func (picker *datePickerData) handleCommand(self View, command PropertyName, data DataObject) bool {
 	switch command {
 	case "textChanged":
 		if text, ok := data.PropertyValue("text"); ok {
@@ -428,9 +348,12 @@ func (picker *datePickerData) handleCommand(self View, command string, data Data
 				oldValue := GetDatePickerValue(picker)
 				picker.properties[DatePickerValue] = value
 				if value != oldValue {
-					for _, listener := range picker.dateChangedListeners {
+					for _, listener := range GetDateChangedListeners(picker) {
 						listener(picker, value, oldValue)
 					}
+					if listener, ok := picker.changeListener[DatePickerValue]; ok {
+						listener(picker, DatePickerValue)
+					}
 				}
 			}
 		}
@@ -440,7 +363,7 @@ func (picker *datePickerData) handleCommand(self View, command string, data Data
 	return picker.viewData.handleCommand(self, command, data)
 }
 
-func getDateProperty(view View, mainTag, shortTag string) (time.Time, bool) {
+func getDateProperty(view View, mainTag, shortTag PropertyName) (time.Time, bool) {
 	valueToTime := func(value any) (time.Time, bool) {
 		if value != nil {
 			switch value := value.(type) {
@@ -449,7 +372,7 @@ func getDateProperty(view View, mainTag, shortTag string) (time.Time, bool) {
 
 			case string:
 				if text, ok := view.Session().resolveConstants(value); ok {
-					if result, err := time.Parse(dateFormat, text); err == nil {
+					if result, ok := stringToDate(text); ok {
 						return result, true
 					}
 				}
@@ -463,12 +386,14 @@ func getDateProperty(view View, mainTag, shortTag string) (time.Time, bool) {
 			return result, true
 		}
 
-		if value := valueFromStyle(view, shortTag); value != nil {
+		for _, tag := range []PropertyName{mainTag, shortTag} {
+			if value := valueFromStyle(view, tag); value != nil {
 				if result, ok := valueToTime(value); ok {
 					return result, true
 				}
 			}
 		}
+	}
 
 	return time.Now(), false
 }

detailsView.go

@@ -13,7 +13,7 @@ const (
 	//
 	// `string` - Summary as a text.
 	// `View` - Summary as a view, in this case it can be quite complex if needed.
-	Summary = "summary"
+	Summary PropertyName = "summary"
 
 	// Expanded is the constant for "expanded" property tag.
 	//
@@ -25,7 +25,7 @@ const (
 	// Values:
 	// `true` or `1` or "true", "yes", "on", "1" - Content is visible.
 	// `false` or `0` or "false", "no", "off", "0" - Content is collapsed(hidden).
-	Expanded = "expanded"
+	Expanded PropertyName = "expanded"
 )
 
 // DetailsView represent a DetailsView view, which is a collapsible container of views
@@ -46,19 +46,21 @@ func NewDetailsView(session Session, params Params) DetailsView {
 }
 
 func newDetailsView(session Session) View {
-	return NewDetailsView(session, nil)
+	return new(detailsViewData)
 }
 
 // Init initialize fields of DetailsView by default values
 func (detailsView *detailsViewData) init(session Session) {
 	detailsView.viewsContainerData.init(session)
 	detailsView.tag = "DetailsView"
+	detailsView.set = detailsView.setFunc
+	detailsView.changed = detailsViewPropertyChanged
 	//detailsView.systemClass = "ruiDetailsView"
 }
 
 func (detailsView *detailsViewData) Views() []View {
 	views := detailsView.viewsContainerData.Views()
-	if summary := detailsView.get(Summary); summary != nil {
+	if summary := detailsView.Get(Summary); summary != nil {
 		switch summary := summary.(type) {
 		case View:
 			return append([]View{summary}, views...)
@@ -67,94 +69,53 @@ func (detailsView *detailsViewData) Views() []View {
 	return views
 }
 
-func (detailsView *detailsViewData) Remove(tag string) {
+func (detailsView *detailsViewData) setFunc(self View, tag PropertyName, value any) []PropertyName {
-	detailsView.remove(strings.ToLower(tag))
-}
-
-func (detailsView *detailsViewData) remove(tag string) {
-	detailsView.viewsContainerData.remove(tag)
-	if detailsView.created {
-		switch tag {
-		case Summary:
-			updateInnerHTML(detailsView.htmlID(), detailsView.Session())
-
-		case Expanded:
-			detailsView.session.removeProperty(detailsView.htmlID(), "open")
-		}
-	}
-}
-
-func (detailsView *detailsViewData) Set(tag string, value any) bool {
-	return detailsView.set(strings.ToLower(tag), value)
-}
-
-func (detailsView *detailsViewData) set(tag string, value any) bool {
-	if value == nil {
-		detailsView.remove(tag)
-		return true
-	}
-
 	switch tag {
 	case Summary:
 		switch value := value.(type) {
 		case string:
-			detailsView.properties[Summary] = value
+			detailsView.setRaw(Summary, value)
 
 		case View:
-			detailsView.properties[Summary] = value
+			detailsView.setRaw(Summary, value)
 			value.setParentID(detailsView.htmlID())
 
 		case DataObject:
 			if view := CreateViewFromObject(detailsView.Session(), value); view != nil {
-				detailsView.properties[Summary] = view
+				detailsView.setRaw(Summary, view)
 				view.setParentID(detailsView.htmlID())
 			} else {
-				return false
+				return nil
 			}
 
 		default:
 			notCompatibleType(tag, value)
-			return false
+			return nil
 		}
-		if detailsView.created {
+		return []PropertyName{tag}
-			updateInnerHTML(detailsView.htmlID(), detailsView.Session())
 	}
 
+	return detailsView.viewsContainerData.setFunc(detailsView, tag, value)
+}
+
+func detailsViewPropertyChanged(view View, tag PropertyName) {
+	switch tag {
+	case Summary:
+		updateInnerHTML(view.htmlID(), view.Session())
+
 	case Expanded:
-		if !detailsView.setBoolProperty(tag, value) {
+		if IsDetailsExpanded(view) {
-			notCompatibleType(tag, value)
+			view.Session().updateProperty(view.htmlID(), "open", "")
-			return false
-		}
-		if detailsView.created {
-			if IsDetailsExpanded(detailsView) {
-				detailsView.session.updateProperty(detailsView.htmlID(), "open", "")
 		} else {
-				detailsView.session.removeProperty(detailsView.htmlID(), "open")
+			view.Session().removeProperty(view.htmlID(), "open")
-			}
 		}
 
 	case NotTranslate:
-		if !detailsView.viewData.set(tag, value) {
+		updateInnerHTML(view.htmlID(), view.Session())
-			return false
-		}
-		if detailsView.created {
-			updateInnerHTML(detailsView.htmlID(), detailsView.Session())
-		}
 
 	default:
-		return detailsView.viewsContainerData.Set(tag, value)
+		viewsContainerPropertyChanged(view, tag)
 	}
-
-	detailsView.propertyChangedEvent(tag)
-	return true
-}
-
-func (detailsView *detailsViewData) Get(tag string) any {
-	return detailsView.get(strings.ToLower(tag))
-}
-
-func (detailsView *detailsViewData) get(tag string) any {
-	return detailsView.viewsContainerData.get(tag)
 }
 
 func (detailsView *detailsViewData) htmlTag() string {
@@ -190,11 +151,13 @@ func (detailsView *detailsViewData) htmlSubviews(self View, buffer *strings.Buil
 	detailsView.viewsContainerData.htmlSubviews(self, buffer)
 }
 
-func (detailsView *detailsViewData) handleCommand(self View, command string, data DataObject) bool {
+func (detailsView *detailsViewData) handleCommand(self View, command PropertyName, data DataObject) bool {
 	if command == "details-open" {
 		if n, ok := dataIntProperty(data, "open"); ok {
 			detailsView.properties[Expanded] = (n != 0)
-			detailsView.propertyChangedEvent(Expanded)
+			if listener, ok := detailsView.changeListener[Current]; ok {
+				listener(detailsView, Current)
+			}
 		}
 		return true
 	}

dropDownList.go

@@ -1,7 +1,6 @@
 package rui
 
 import (
-	"fmt"
 	"strconv"
 	"strings"
 )
@@ -19,20 +18,15 @@ import (
 // index - Index of a newly selected item.
 //
 // Allowed listener formats:
-const DropDownEvent = "drop-down-event"
+const DropDownEvent PropertyName = "drop-down-event"
 
 // DropDownList represent a DropDownList view
 type DropDownList interface {
 	View
-	getItems() []string
 }
 
 type dropDownListData struct {
 	viewData
-	items            []string
-	disabledItems    []any
-	itemSeparators   []any
-	dropDownListener []func(DropDownList, int, int)
 }
 
 // NewDropDownList create new DropDownList object and return it
@@ -44,167 +38,86 @@ func NewDropDownList(session Session, params Params) DropDownList {
 }
 
 func newDropDownList(session Session) View {
-	return NewDropDownList(session, nil)
+	return new(dropDownListData)
 }
 
 func (list *dropDownListData) init(session Session) {
 	list.viewData.init(session)
 	list.tag = "DropDownList"
 	list.hasHtmlDisabled = true
-	list.items = []string{}
+	list.normalize = normalizeDropDownListTag
-	list.disabledItems = []any{}
+	list.set = dropDownListSet
-	list.itemSeparators = []any{}
+	list.changed = dropDownListPropertyChanged
-	list.dropDownListener = []func(DropDownList, int, int){}
-}
-
-func (list *dropDownListData) String() string {
-	return getViewString(list, nil)
 }
 
 func (list *dropDownListData) Focusable() bool {
 	return true
 }
 
-func (list *dropDownListData) Remove(tag string) {
+func normalizeDropDownListTag(tag PropertyName) PropertyName {
-	list.remove(strings.ToLower(tag))
+	tag = defaultNormalize(tag)
+	if tag == "separators" {
+		return ItemSeparators
+	}
+	return tag
 }
 
-func (list *dropDownListData) remove(tag string) {
+func dropDownListSet(view View, tag PropertyName, value any) []PropertyName {
 	switch tag {
 	case Items:
-		if len(list.items) > 0 {
+		if items, ok := anyToStringArray(value, ""); ok {
-			list.items = []string{}
+			return setArrayPropertyValue(view, tag, items)
-			if list.created {
-				updateInnerHTML(list.htmlID(), list.session)
-			}
-			list.propertyChangedEvent(tag)
 		}
+		notCompatibleType(Items, value)
+		return nil
 
-	case DisabledItems:
+	case DisabledItems, ItemSeparators:
-		if len(list.disabledItems) > 0 {
+		if items, ok := parseIndicesArray(value); ok {
-			list.disabledItems = []any{}
+			return setArrayPropertyValue(view, tag, items)
-			if list.created {
-				updateInnerHTML(list.htmlID(), list.session)
-			}
-			list.propertyChangedEvent(tag)
-		}
-
-	case ItemSeparators, "separators":
-		if len(list.itemSeparators) > 0 {
-			list.itemSeparators = []any{}
-			if list.created {
-				updateInnerHTML(list.htmlID(), list.session)
-			}
-			list.propertyChangedEvent(ItemSeparators)
 		}
+		notCompatibleType(tag, value)
+		return nil
 
 	case DropDownEvent:
-		if len(list.dropDownListener) > 0 {
+		return setEventWithOldListener[DropDownList, int](view, tag, value)
-			list.dropDownListener = []func(DropDownList, int, int){}
-			list.propertyChangedEvent(tag)
-		}
 
 	case Current:
-		oldCurrent := GetCurrent(list)
+		if view, ok := view.(View); ok {
-		delete(list.properties, Current)
+			view.setRaw("old-current", GetCurrent(view))
-		if oldCurrent != 0 {
+		}
-			if list.created {
+		return setIntProperty(view, Current, value)
-				list.session.callFunc("selectDropDownListItem", list.htmlID(), 0)
+	}
+
+	return viewSet(view, tag, value)
+}
+
+func dropDownListPropertyChanged(view View, tag PropertyName) {
+	switch tag {
+	case Items, DisabledItems, ItemSeparators:
+		updateInnerHTML(view.htmlID(), view.Session())
+
+	case Current:
+		current := GetCurrent(view)
+		view.Session().callFunc("selectDropDownListItem", view.htmlID(), current)
+
+		if list, ok := view.(DropDownList); ok {
+			oldCurrent := -1
+			if value := view.getRaw("old-current"); value != nil {
+				if n, ok := value.(int); ok {
+					oldCurrent = n
+				}
+			}
+
+			for _, listener := range GetDropDownListeners(view) {
+				listener(list, current, oldCurrent)
 			}
-			list.onSelectedItemChanged(0, oldCurrent)
 		}
 
 	default:
-		list.viewData.remove(tag)
+		viewPropertyChanged(view, tag)
 	}
 }
 
-func (list *dropDownListData) Set(tag string, value any) bool {
-	return list.set(strings.ToLower(tag), value)
-}
-
-func (list *dropDownListData) set(tag string, value any) bool {
-	if value == nil {
-		list.remove(tag)
-		return true
-	}
-
-	switch tag {
-	case Items:
-		return list.setItems(value)
-
-	case DisabledItems:
-		items, ok := list.parseIndicesArray(value)
-		if !ok {
-			notCompatibleType(tag, value)
-			return false
-		}
-		list.disabledItems = items
-		if list.created {
-			updateInnerHTML(list.htmlID(), list.session)
-		}
-		list.propertyChangedEvent(tag)
-		return true
-
-	case ItemSeparators, "separators":
-		items, ok := list.parseIndicesArray(value)
-		if !ok {
-			notCompatibleType(ItemSeparators, value)
-			return false
-		}
-		list.itemSeparators = items
-		if list.created {
-			updateInnerHTML(list.htmlID(), list.session)
-		}
-		list.propertyChangedEvent(ItemSeparators)
-		return true
-
-	case DropDownEvent:
-		listeners, ok := valueToEventWithOldListeners[DropDownList, int](value)
-		if !ok {
-			notCompatibleType(tag, value)
-			return false
-		} else if listeners == nil {
-			listeners = []func(DropDownList, int, int){}
-		}
-		list.dropDownListener = listeners
-		list.propertyChangedEvent(tag)
-		return true
-
-	case Current:
-		oldCurrent := GetCurrent(list)
-		if !list.setIntProperty(Current, value) {
-			return false
-		}
-
-		if current := GetCurrent(list); oldCurrent != current {
-			if list.created {
-				list.session.callFunc("selectDropDownListItem", list.htmlID(), current)
-			}
-			list.onSelectedItemChanged(current, oldCurrent)
-		}
-		return true
-	}
-
-	return list.viewData.set(tag, value)
-}
-
-func (list *dropDownListData) setItems(value any) bool {
-	items, ok := anyToStringArray(value)
-	if !ok {
-		notCompatibleType(Items, value)
-		return false
-	}
-
-	list.items = items
-	if list.created {
-		updateInnerHTML(list.htmlID(), list.session)
-	}
-
-	list.propertyChangedEvent(Items)
-	return true
-}
-
 func intArrayToStringArray[T int | uint | int8 | uint8 | int16 | uint16 | int32 | uint32 | int64 | uint64](array []T) []string {
 	items := make([]string, len(array))
 	for i, val := range array {
@@ -213,150 +126,11 @@ func intArrayToStringArray[T int | uint | int8 | uint8 | int16 | uint16 | int32
 	return items
 }
 
-func anyToStringArray(value any) ([]string, bool) {
+func parseIndicesArray(value any) ([]any, bool) {
-
 	switch value := value.(type) {
-	case string:
+	case int:
-		return []string{value}, true
+		return []any{value}, true
 
-	case []string:
-		return value, true
-
-	case []DataValue:
-		items := make([]string, 0, len(value))
-		for _, val := range value {
-			if !val.IsObject() {
-				items = append(items, val.Value())
-			}
-		}
-		return items, true
-
-	case []fmt.Stringer:
-		items := make([]string, len(value))
-		for i, str := range value {
-			items[i] = str.String()
-		}
-		return items, true
-
-	case []Color:
-		items := make([]string, len(value))
-		for i, str := range value {
-			items[i] = str.String()
-		}
-		return items, true
-
-	case []SizeUnit:
-		items := make([]string, len(value))
-		for i, str := range value {
-			items[i] = str.String()
-		}
-		return items, true
-
-	case []AngleUnit:
-		items := make([]string, len(value))
-		for i, str := range value {
-			items[i] = str.String()
-		}
-		return items, true
-
-	case []float32:
-		items := make([]string, len(value))
-		for i, val := range value {
-			items[i] = fmt.Sprintf("%g", float64(val))
-		}
-		return items, true
-
-	case []float64:
-		items := make([]string, len(value))
-		for i, val := range value {
-			items[i] = fmt.Sprintf("%g", val)
-		}
-		return items, true
-
-	case []int:
-		return intArrayToStringArray(value), true
-
-	case []uint:
-		return intArrayToStringArray(value), true
-
-	case []int8:
-		return intArrayToStringArray(value), true
-
-	case []uint8:
-		return intArrayToStringArray(value), true
-
-	case []int16:
-		return intArrayToStringArray(value), true
-
-	case []uint16:
-		return intArrayToStringArray(value), true
-
-	case []int32:
-		return intArrayToStringArray(value), true
-
-	case []uint32:
-		return intArrayToStringArray(value), true
-
-	case []int64:
-		return intArrayToStringArray(value), true
-
-	case []uint64:
-		return intArrayToStringArray(value), true
-
-	case []bool:
-		items := make([]string, len(value))
-		for i, val := range value {
-			if val {
-				items[i] = "true"
-			} else {
-				items[i] = "false"
-			}
-		}
-		return items, true
-
-	case []any:
-		items := make([]string, 0, len(value))
-		for _, v := range value {
-			switch val := v.(type) {
-			case string:
-				items = append(items, val)
-
-			case fmt.Stringer:
-				items = append(items, val.String())
-
-			case bool:
-				if val {
-					items = append(items, "true")
-				} else {
-					items = append(items, "false")
-				}
-
-			case float32:
-				items = append(items, fmt.Sprintf("%g", float64(val)))
-
-			case float64:
-				items = append(items, fmt.Sprintf("%g", val))
-
-			case rune:
-				items = append(items, string(val))
-
-			default:
-				if n, ok := isInt(v); ok {
-					items = append(items, strconv.Itoa(n))
-				} else {
-					return []string{}, false
-				}
-			}
-		}
-
-		return items, true
-	}
-
-	return []string{}, false
-}
-
-func (list *dropDownListData) parseIndicesArray(value any) ([]any, bool) {
-	switch value := value.(type) {
 	case []int:
 		items := make([]any, len(value))
 		for i, n := range value {
@@ -365,108 +139,72 @@ func (list *dropDownListData) parseIndicesArray(value any) ([]any, bool) {
 		return items, true
 
 	case []any:
-		items := make([]any, len(value))
+		items := make([]any, 0, len(value))
-		for i, val := range value {
+		for _, val := range value {
-			if val == nil {
+			if val != nil {
-				return nil, false
-			}
-
 				switch val := val.(type) {
 				case string:
 					if isConstantName(val) {
-					items[i] = val
+						items = append(items, val)
-				} else {
+					} else if n, err := strconv.Atoi(val); err == nil {
-					n, err := strconv.Atoi(val)
+						items = append(items, n)
-					if err != nil {
-						return nil, false
-					}
-					items[i] = n
-				}
-			default:
-				if n, ok := isInt(val); ok {
-					items[i] = n
 					} else {
 						return nil, false
 					}
-			}
 
+				default:
+					if n, ok := isInt(val); ok {
+						items = append(items, n)
+					} else {
+						return nil, false
+					}
+				}
+			}
+		}
+		return items, true
+
+	case []string:
+		items := make([]any, 0, len(value))
+		for _, str := range value {
+			if str = strings.Trim(str, " \t"); str != "" {
+				if isConstantName(str) {
+					items = append(items, str)
+				} else if n, err := strconv.Atoi(str); err == nil {
+					items = append(items, n)
+				} else {
+					return nil, false
+				}
+			}
 		}
 		return items, true
 
 	case string:
-		values := strings.Split(value, ",")
+		return parseIndicesArray(strings.Split(value, ","))
-		items := make([]any, len(values))
-		for i, str := range values {
-			str = strings.Trim(str, " ")
-			if str == "" {
-				return nil, false
-			}
-			if isConstantName(str) {
-				items[i] = str
-			} else {
-				n, err := strconv.Atoi(str)
-				if err != nil {
-					return nil, false
-				}
-				items[i] = n
-			}
-		}
-		return items, true
 
 	case []DataValue:
-		items := make([]any, 0, len(value))
+		items := make([]string, 0, len(value))
 		for _, val := range value {
 			if !val.IsObject() {
 				items = append(items, val.Value())
 			}
 		}
-		return list.parseIndicesArray(items)
+		return parseIndicesArray(items)
 	}
 
 	return nil, false
 }
 
-func (list *dropDownListData) Get(tag string) any {
-	return list.get(strings.ToLower(tag))
-}
-
-func (list *dropDownListData) get(tag string) any {
-	switch tag {
-	case Items:
-		return list.items
-
-	case DisabledItems:
-		return list.disabledItems
-
-	case ItemSeparators:
-		return list.itemSeparators
-
-	case Current:
-		result, _ := intProperty(list, Current, list.session, 0)
-		return result
-
-	case DropDownEvent:
-		return list.dropDownListener
-	}
-
-	return list.viewData.get(tag)
-}
-
-func (list *dropDownListData) getItems() []string {
-	return list.items
-}
-
 func (list *dropDownListData) htmlTag() string {
 	return "select"
 }
 
 func (list *dropDownListData) htmlSubviews(self View, buffer *strings.Builder) {
-	if list.items != nil {
+	if items := GetDropDownItems(list); len(items) > 0 {
 		current := GetCurrent(list)
 		notTranslate := GetNotTranslate(list)
 		disabledItems := GetDropDownDisabledItems(list)
 		separators := GetDropDownItemSeparators(list)
-		for i, item := range list.items {
+		for i, item := range items {
 			disabled := false
 			for _, index := range disabledItems {
 				if i == index {
@@ -503,22 +241,18 @@ func (list *dropDownListData) htmlProperties(self View, buffer *strings.Builder)
 	buffer.WriteString(` size="1" onchange="dropDownListEvent(this, event)"`)
 }
 
-func (list *dropDownListData) onSelectedItemChanged(number, old int) {
+func (list *dropDownListData) handleCommand(self View, command PropertyName, data DataObject) bool {
-	for _, listener := range list.dropDownListener {
-		listener(list, number, old)
-	}
-	list.propertyChangedEvent(Current)
-}
-
-func (list *dropDownListData) handleCommand(self View, command string, data DataObject) bool {
 	switch command {
 	case "itemSelected":
 		if text, ok := data.PropertyValue("number"); ok {
 			if number, err := strconv.Atoi(text); err == nil {
-				if GetCurrent(list) != number && number >= 0 && number < len(list.items) {
+				items := GetDropDownItems(list)
+				if GetCurrent(list) != number && number >= 0 && number < len(items) {
 					old := GetCurrent(list)
 					list.properties[Current] = number
-					list.onSelectedItemChanged(number, old)
+					for _, listener := range GetDropDownListeners(list) {
+						listener(list, number, old)
+					}
 				}
 			} else {
 				ErrorLog(err.Error())
@@ -544,14 +278,16 @@ func GetDropDownItems(view View, subviewID ...string) []string {
 		view = ViewByID(view, subviewID[0])
 	}
 	if view != nil {
-		if list, ok := view.(DropDownList); ok {
+		if value := view.Get(Items); value != nil {
-			return list.getItems()
+			if items, ok := value.([]string); ok {
+				return items
+			}
 		}
 	}
 	return []string{}
 }
 
-func getIndicesArray(view View, tag string) []int {
+func getIndicesArray(view View, tag PropertyName) []int {
 	if view != nil {
 		if value := view.Get(tag); value != nil {
 			if values, ok := value.([]any); ok {

editView.go

@@ -26,7 +26,7 @@ const (
 	// `func(newText string)`,
 	// `func(editView rui.EditView)`,
 	// `func()`.
-	EditTextChangedEvent = "edit-text-changed"
+	EditTextChangedEvent PropertyName = "edit-text-changed"
 
 	// EditViewType is the constant for "edit-view-type" property tag.
 	//
@@ -43,7 +43,7 @@ const (
 	// `4`(`URLText`) or "url" - Internet address input editor.
 	// `5`(`PhoneText`) or "phone" - Phone number editor.
 	// `6`(`MultiLineText`) or "multiline" - Multi-line text editor.
-	EditViewType = "edit-view-type"
+	EditViewType PropertyName = "edit-view-type"
 
 	// EditViewPattern is the constant for "edit-view-pattern" property tag.
 	//
@@ -51,7 +51,7 @@ const (
 	// Regular expression to limit editing of a text.
 	//
 	// Supported types: `string`.
-	EditViewPattern = "edit-view-pattern"
+	EditViewPattern PropertyName = "edit-view-pattern"
 
 	// Spellcheck is the constant for "spellcheck" property tag.
 	//
@@ -64,7 +64,7 @@ const (
 	// Values:
 	// `true` or `1` or "true", "yes", "on", "1" - Enable spell checker for text.
 	// `false` or `0` or "false", "no", "off", "0" - Disable spell checker for text.
-	Spellcheck = "spellcheck"
+	Spellcheck PropertyName = "spellcheck"
 )
 
 // Constants for the values of an [EditView] "edit-view-type" property
@@ -97,12 +97,11 @@ type EditView interface {
 
 	// AppendText appends text to the current text of an EditView view
 	AppendText(text string)
+	textChanged(newText, oldText string)
 }
 
 type editViewData struct {
 	viewData
-	dataList
-	textChangeListeners []func(EditView, string, string)
 }
 
 // NewEditView create new EditView object and return it
@@ -114,27 +113,24 @@ func NewEditView(session Session, params Params) EditView {
 }
 
 func newEditView(session Session) View {
-	return NewEditView(session, nil)
+	return new(editViewData) // NewEditView(session, nil)
 }
 
 func (edit *editViewData) init(session Session) {
 	edit.viewData.init(session)
 	edit.hasHtmlDisabled = true
-	edit.textChangeListeners = []func(EditView, string, string){}
 	edit.tag = "EditView"
-	edit.dataListInit()
+	edit.normalize = normalizeEditViewTag
-}
+	edit.set = editViewSet
-
+	edit.changed = editViewPropertyChanged
-func (edit *editViewData) String() string {
-	return getViewString(edit, nil)
 }
 
 func (edit *editViewData) Focusable() bool {
 	return true
 }
 
-func (edit *editViewData) normalizeTag(tag string) string {
+func normalizeEditViewTag(tag PropertyName) PropertyName {
-	tag = strings.ToLower(tag)
+	tag = defaultNormalize(tag)
 	switch tag {
 	case Type, "edit-type":
 		return EditViewType
@@ -149,279 +145,109 @@ func (edit *editViewData) normalizeTag(tag string) string {
 		return EditWrap
 	}
 
-	return edit.normalizeDataListTag(tag)
+	return normalizeDataListTag(tag)
 }
 
-func (edit *editViewData) Remove(tag string) {
+func editViewSet(view View, tag PropertyName, value any) []PropertyName {
-	edit.remove(edit.normalizeTag(tag))
-}
-
-func (edit *editViewData) remove(tag string) {
-	_, exists := edit.properties[tag]
 	switch tag {
-	case Hint:
-		if exists {
-			delete(edit.properties, Hint)
-			if edit.created {
-				edit.session.removeProperty(edit.htmlID(), "placeholder")
-			}
-			edit.propertyChangedEvent(tag)
-		}
-
-	case MaxLength:
-		if exists {
-			delete(edit.properties, MaxLength)
-			if edit.created {
-				edit.session.removeProperty(edit.htmlID(), "maxlength")
-			}
-			edit.propertyChangedEvent(tag)
-		}
-
-	case ReadOnly, Spellcheck:
-		if exists {
-			delete(edit.properties, tag)
-			if edit.created {
-				edit.session.updateProperty(edit.htmlID(), tag, false)
-			}
-			edit.propertyChangedEvent(tag)
-		}
-
-	case EditTextChangedEvent:
-		if len(edit.textChangeListeners) > 0 {
-			edit.textChangeListeners = []func(EditView, string, string){}
-			edit.propertyChangedEvent(tag)
-		}
-
 	case Text:
-		if exists {
+		if text, ok := value.(string); ok {
-			oldText := GetText(edit)
+			old := ""
-			delete(edit.properties, tag)
+			if val := view.getRaw(Text); val != nil {
-			if oldText != "" {
+				if txt, ok := val.(string); ok {
-				edit.textChanged("", oldText)
+					old = txt
-				if edit.created {
-					edit.session.callFunc("setInputValue", edit.htmlID(), "")
 				}
 			}
+			view.setRaw("old-text", old)
+			view.setRaw(tag, text)
+			return []PropertyName{tag}
 		}
 
-	case EditViewPattern:
+		notCompatibleType(tag, value)
-		if exists {
+		return nil
-			oldText := GetEditViewPattern(edit)
-			delete(edit.properties, tag)
-			if oldText != "" {
-				if edit.created {
-					edit.session.removeProperty(edit.htmlID(), Pattern)
-				}
-				edit.propertyChangedEvent(tag)
-			}
-		}
 
-	case EditViewType:
+	case Hint:
-		if exists {
+		if text, ok := value.(string); ok {
-			oldType := GetEditViewType(edit)
+			return setStringPropertyValue(view, tag, strings.Trim(text, " \t\n"))
-			delete(edit.properties, tag)
-			if oldType != 0 {
-				if edit.created {
-					updateInnerHTML(edit.parentHTMLID(), edit.session)
-				}
-				edit.propertyChangedEvent(tag)
-			}
-		}
-
-	case EditWrap:
-		if exists {
-			oldWrap := IsEditViewWrap(edit)
-			delete(edit.properties, tag)
-			if GetEditViewType(edit) == MultiLineText {
-				if wrap := IsEditViewWrap(edit); wrap != oldWrap {
-					if edit.created {
-						if wrap {
-							edit.session.updateProperty(edit.htmlID(), "wrap", "soft")
-						} else {
-							edit.session.updateProperty(edit.htmlID(), "wrap", "off")
-						}
-					}
-					edit.propertyChangedEvent(tag)
-				}
-			}
 		}
+		notCompatibleType(tag, value)
+		return nil
 
 	case DataList:
-		if len(edit.dataList.dataList) > 0 {
+		setDataList(view, value, "")
-			edit.setDataList(edit, []string{}, true)
+
+	case EditTextChangedEvent:
+		return setEventWithOldListener[EditView, string](view, tag, value)
 	}
 
-	default:
+	return viewSet(view, tag, value)
-		edit.viewData.remove(tag)
-	}
 }
 
-func (edit *editViewData) Set(tag string, value any) bool {
+func editViewPropertyChanged(view View, tag PropertyName) {
-	return edit.set(edit.normalizeTag(tag), value)
+	session := view.Session()
-}
-
-func (edit *editViewData) set(tag string, value any) bool {
-	if value == nil {
-		edit.remove(tag)
-		return true
-	}
 
 	switch tag {
 	case Text:
-		if text, ok := value.(string); ok {
+		text := GetText(view)
-			oldText := GetText(edit)
+		session.callFunc("setInputValue", view.htmlID(), text)
-			edit.properties[Text] = text
+
-			if text = GetText(edit); oldText != text {
+		if edit, ok := view.(EditView); ok {
-				edit.textChanged(text, oldText)
+			old := ""
-				if edit.created {
+			if val := view.getRaw("old-text"); val != nil {
-					edit.session.callFunc("setInputValue", edit.htmlID(), text)
+				if txt, ok := val.(string); ok {
+					old = txt
 				}
 			}
-			return true
+			edit.textChanged(text, old)
 		}
-		return false
 
 	case Hint:
-		if text, ok := value.(string); ok {
+		if text := GetHint(view); text != "" {
-			oldText := GetHint(edit)
+			session.updateProperty(view.htmlID(), "placeholder", text)
-			edit.properties[Hint] = text
-			if text = GetHint(edit); oldText != text {
-				if edit.created {
-					if text != "" {
-						edit.session.updateProperty(edit.htmlID(), "placeholder", text)
 		} else {
-						edit.session.removeProperty(edit.htmlID(), "placeholder")
+			session.removeProperty(view.htmlID(), "placeholder")
 		}
-				}
-				edit.propertyChangedEvent(tag)
-			}
-			return true
-		}
-		return false
 
 	case MaxLength:
-		oldMaxLength := GetMaxLength(edit)
+		if maxLength := GetMaxLength(view); maxLength > 0 {
-		if edit.setIntProperty(MaxLength, value) {
+			session.updateProperty(view.htmlID(), "maxlength", strconv.Itoa(maxLength))
-			if maxLength := GetMaxLength(edit); maxLength != oldMaxLength {
-				if edit.created {
-					if maxLength > 0 {
-						edit.session.updateProperty(edit.htmlID(), "maxlength", strconv.Itoa(maxLength))
 		} else {
-						edit.session.removeProperty(edit.htmlID(), "maxlength")
+			session.removeProperty(view.htmlID(), "maxlength")
 		}
-				}
-				edit.propertyChangedEvent(tag)
-			}
-			return true
-		}
-		return false
 
 	case ReadOnly:
-		if edit.setBoolProperty(ReadOnly, value) {
+		if IsReadOnly(view) {
-			if edit.created {
+			session.updateProperty(view.htmlID(), "readonly", "")
-				if IsReadOnly(edit) {
-					edit.session.updateProperty(edit.htmlID(), ReadOnly, "")
 		} else {
-					edit.session.removeProperty(edit.htmlID(), ReadOnly)
+			session.removeProperty(view.htmlID(), "readonly")
 		}
-			}
-			edit.propertyChangedEvent(tag)
-			return true
-		}
-		return false
 
 	case Spellcheck:
-		if edit.setBoolProperty(Spellcheck, value) {
+		session.updateProperty(view.htmlID(), "spellcheck", IsSpellcheck(view))
-			if edit.created {
-				edit.session.updateProperty(edit.htmlID(), Spellcheck, IsSpellcheck(edit))
-			}
-			edit.propertyChangedEvent(tag)
-			return true
-		}
-		return false
 
 	case EditViewPattern:
-		oldText := GetEditViewPattern(edit)
+		if text := GetEditViewPattern(view); text != "" {
-		if text, ok := value.(string); ok {
+			session.updateProperty(view.htmlID(), "pattern", text)
-			edit.properties[EditViewPattern] = text
-			if text = GetEditViewPattern(edit); oldText != text {
-				if edit.created {
-					if text != "" {
-						edit.session.updateProperty(edit.htmlID(), Pattern, text)
 		} else {
-						edit.session.removeProperty(edit.htmlID(), Pattern)
+			session.removeProperty(view.htmlID(), "pattern")
 		}
-				}
-				edit.propertyChangedEvent(tag)
-			}
-			return true
-		}
-		return false
 
 	case EditViewType:
-		oldType := GetEditViewType(edit)
+		updateInnerHTML(view.parentHTMLID(), session)
-		if edit.setEnumProperty(EditViewType, value, enumProperties[EditViewType].values) {
-			if GetEditViewType(edit) != oldType {
-				if edit.created {
-					updateInnerHTML(edit.parentHTMLID(), edit.session)
-				}
-				edit.propertyChangedEvent(tag)
-			}
-			return true
-		}
-		return false
 
 	case EditWrap:
-		oldWrap := IsEditViewWrap(edit)
+		if wrap := IsEditViewWrap(view); wrap {
-		if edit.setBoolProperty(EditWrap, value) {
+			session.updateProperty(view.htmlID(), "wrap", "soft")
-			if GetEditViewType(edit) == MultiLineText {
-				if wrap := IsEditViewWrap(edit); wrap != oldWrap {
-					if edit.created {
-						if wrap {
-							edit.session.updateProperty(edit.htmlID(), "wrap", "soft")
 		} else {
-							edit.session.updateProperty(edit.htmlID(), "wrap", "off")
+			session.updateProperty(view.htmlID(), "wrap", "off")
 		}
-					}
-					edit.propertyChangedEvent(tag)
-				}
-			}
-			return true
-		}
-		return false
 
 	case DataList:
-		return edit.setDataList(edit, value, edit.created)
+		updateInnerHTML(view.htmlID(), session)
 
-	case EditTextChangedEvent:
+	default:
-		listeners, ok := valueToEventWithOldListeners[EditView, string](value)
+		viewPropertyChanged(view, tag)
-		if !ok {
-			notCompatibleType(tag, value)
-			return false
-		} else if listeners == nil {
-			listeners = []func(EditView, string, string){}
 	}
-		edit.textChangeListeners = listeners
-		edit.propertyChangedEvent(tag)
-		return true
-	}
-
-	return edit.viewData.set(tag, value)
-}
-
-func (edit *editViewData) Get(tag string) any {
-	return edit.get(edit.normalizeTag(tag))
-}
-
-func (edit *editViewData) get(tag string) any {
-	switch tag {
-	case EditTextChangedEvent:
-		return edit.textChangeListeners
-
-	case DataList:
-		return edit.dataList.dataList
-	}
-	return edit.viewData.get(tag)
 }
 
 func (edit *editViewData) AppendText(text string) {
@@ -432,21 +258,24 @@ func (edit *editViewData) AppendText(text string) {
 				textValue += text
 				edit.properties[Text] = textValue
 				edit.session.callFunc("appendToInnerHTML", edit.htmlID(), text)
+				edit.session.callFunc("appendToInputValue", edit.htmlID(), text)
 				edit.textChanged(textValue, oldText)
 				return
 			}
 		}
-		edit.set(Text, text)
+		edit.setRaw(Text, text)
 	} else {
-		edit.set(Text, GetText(edit)+text)
+		edit.setRaw(Text, GetText(edit)+text)
 	}
 }
 
 func (edit *editViewData) textChanged(newText, oldText string) {
-	for _, listener := range edit.textChangeListeners {
+	for _, listener := range GetTextChangedListeners(edit) {
 		listener(edit, newText, oldText)
 	}
-	edit.propertyChangedEvent(Text)
+	if listener, ok := edit.changeListener[Text]; ok {
+		listener(edit, Text)
+	}
 }
 
 func (edit *editViewData) htmlTag() string {
@@ -462,7 +291,9 @@ func (edit *editViewData) htmlSubviews(self View, buffer *strings.Builder) {
 			buffer.WriteString(text)
 		}
 	}
-	edit.dataListHtmlSubviews(self, buffer)
+	dataListHtmlSubviews(self, buffer, func(text string, session Session) string {
+		return text
+	})
 }
 
 func (edit *editViewData) htmlProperties(self View, buffer *strings.Builder) {
@@ -547,16 +378,16 @@ func (edit *editViewData) htmlProperties(self View, buffer *strings.Builder) {
 		}
 	}
 
-	edit.dataListHtmlProperties(edit, buffer)
+	dataListHtmlProperties(edit, buffer)
 }
 
-func (edit *editViewData) handleCommand(self View, command string, data DataObject) bool {
+func (edit *editViewData) handleCommand(self View, command PropertyName, data DataObject) bool {
 	switch command {
 	case "textChanged":
 		oldText := GetText(edit)
 		if text, ok := data.PropertyValue("text"); ok {
-			edit.properties[Text] = text
+			edit.setRaw(Text, text)
-			if text := GetText(edit); text != oldText {
+			if text != oldText {
 				edit.textChanged(text, oldText)
 			}
 		}

events.go

@@ -0,0 +1,526 @@
+package rui
+
+import "strings"
+
+var eventJsFunc = map[PropertyName]struct{ jsEvent, jsFunc string }{
+	FocusEvent:              {jsEvent: "onfocus", jsFunc: "focusEvent"},
+	LostFocusEvent:          {jsEvent: "onblur", jsFunc: "blurEvent"},
+	KeyDownEvent:            {jsEvent: "onkeydown", jsFunc: "keyDownEvent"},
+	KeyUpEvent:              {jsEvent: "onkeyup", jsFunc: "keyUpEvent"},
+	ClickEvent:              {jsEvent: "onclick", jsFunc: "clickEvent"},
+	DoubleClickEvent:        {jsEvent: "ondblclick", jsFunc: "doubleClickEvent"},
+	MouseDown:               {jsEvent: "onmousedown", jsFunc: "mouseDownEvent"},
+	MouseUp:                 {jsEvent: "onmouseup", jsFunc: "mouseUpEvent"},
+	MouseMove:               {jsEvent: "onmousemove", jsFunc: "mouseMoveEvent"},
+	MouseOut:                {jsEvent: "onmouseout", jsFunc: "mouseOutEvent"},
+	MouseOver:               {jsEvent: "onmouseover", jsFunc: "mouseOverEvent"},
+	ContextMenuEvent:        {jsEvent: "oncontextmenu", jsFunc: "contextMenuEvent"},
+	PointerDown:             {jsEvent: "onpointerdown", jsFunc: "pointerDownEvent"},
+	PointerUp:               {jsEvent: "onpointerup", jsFunc: "pointerUpEvent"},
+	PointerMove:             {jsEvent: "onpointermove", jsFunc: "pointerMoveEvent"},
+	PointerCancel:           {jsEvent: "onpointercancel", jsFunc: "pointerCancelEvent"},
+	PointerOut:              {jsEvent: "onpointerout", jsFunc: "pointerOutEvent"},
+	PointerOver:             {jsEvent: "onpointerover", jsFunc: "pointerOverEvent"},
+	TouchStart:              {jsEvent: "ontouchstart", jsFunc: "touchStartEvent"},
+	TouchEnd:                {jsEvent: "ontouchend", jsFunc: "touchEndEvent"},
+	TouchMove:               {jsEvent: "ontouchmove", jsFunc: "touchMoveEvent"},
+	TouchCancel:             {jsEvent: "ontouchcancel", jsFunc: "touchCancelEvent"},
+	TransitionRunEvent:      {jsEvent: "ontransitionrun", jsFunc: "transitionRunEvent"},
+	TransitionStartEvent:    {jsEvent: "ontransitionstart", jsFunc: "transitionStartEvent"},
+	TransitionEndEvent:      {jsEvent: "ontransitionend", jsFunc: "transitionEndEvent"},
+	TransitionCancelEvent:   {jsEvent: "ontransitioncancel", jsFunc: "transitionCancelEvent"},
+	AnimationStartEvent:     {jsEvent: "onanimationstart", jsFunc: "animationStartEvent"},
+	AnimationEndEvent:       {jsEvent: "onanimationend", jsFunc: "animationEndEvent"},
+	AnimationIterationEvent: {jsEvent: "onanimationiteration", jsFunc: "animationIterationEvent"},
+	AnimationCancelEvent:    {jsEvent: "onanimationcancel", jsFunc: "animationCancelEvent"},
+}
+
+func valueToNoParamListeners[V any](value any) ([]func(V), bool) {
+	if value == nil {
+		return nil, true
+	}
+
+	switch value := value.(type) {
+	case func(V):
+		return []func(V){value}, true
+
+	case func():
+		fn := func(V) {
+			value()
+		}
+		return []func(V){fn}, true
+
+	case []func(V):
+		if len(value) == 0 {
+			return nil, true
+		}
+		for _, fn := range value {
+			if fn == nil {
+				return nil, false
+			}
+		}
+		return value, true
+
+	case []func():
+		count := len(value)
+		if count == 0 {
+			return nil, true
+		}
+		listeners := make([]func(V), count)
+		for i, v := range value {
+			if v == nil {
+				return nil, false
+			}
+			listeners[i] = func(V) {
+				v()
+			}
+		}
+		return listeners, true
+
+	case []any:
+		count := len(value)
+		if count == 0 {
+			return nil, true
+		}
+		listeners := make([]func(V), count)
+		for i, v := range value {
+			if v == nil {
+				return nil, false
+			}
+			switch v := v.(type) {
+			case func(V):
+				listeners[i] = v
+
+			case func():
+				listeners[i] = func(V) {
+					v()
+				}
+
+			default:
+				return nil, false
+			}
+		}
+		return listeners, true
+	}
+
+	return nil, false
+}
+
+func valueToEventListeners[V View, E any](value any) ([]func(V, E), bool) {
+	if value == nil {
+		return nil, true
+	}
+
+	switch value := value.(type) {
+	case func(V, E):
+		return []func(V, E){value}, true
+
+	case func(E):
+		fn := func(_ V, event E) {
+			value(event)
+		}
+		return []func(V, E){fn}, true
+
+	case func(V):
+		fn := func(view V, _ E) {
+			value(view)
+		}
+		return []func(V, E){fn}, true
+
+	case func():
+		fn := func(V, E) {
+			value()
+		}
+		return []func(V, E){fn}, true
+
+	case []func(V, E):
+		if len(value) == 0 {
+			return nil, true
+		}
+		for _, fn := range value {
+			if fn == nil {
+				return nil, false
+			}
+		}
+		return value, true
+
+	case []func(E):
+		count := len(value)
+		if count == 0 {
+			return nil, true
+		}
+		listeners := make([]func(V, E), count)
+		for i, v := range value {
+			if v == nil {
+				return nil, false
+			}
+			listeners[i] = func(_ V, event E) {
+				v(event)
+			}
+		}
+		return listeners, true
+
+	case []func(V):
+		count := len(value)
+		if count == 0 {
+			return nil, true
+		}
+		listeners := make([]func(V, E), count)
+		for i, v := range value {
+			if v == nil {
+				return nil, false
+			}
+			listeners[i] = func(view V, _ E) {
+				v(view)
+			}
+		}
+		return listeners, true
+
+	case []func():
+		count := len(value)
+		if count == 0 {
+			return nil, true
+		}
+		listeners := make([]func(V, E), count)
+		for i, v := range value {
+			if v == nil {
+				return nil, false
+			}
+			listeners[i] = func(V, E) {
+				v()
+			}
+		}
+		return listeners, true
+
+	case []any:
+		count := len(value)
+		if count == 0 {
+			return nil, true
+		}
+		listeners := make([]func(V, E), count)
+		for i, v := range value {
+			if v == nil {
+				return nil, false
+			}
+			switch v := v.(type) {
+			case func(V, E):
+				listeners[i] = v
+
+			case func(E):
+				listeners[i] = func(_ V, event E) {
+					v(event)
+				}
+
+			case func(V):
+				listeners[i] = func(view V, _ E) {
+					v(view)
+				}
+
+			case func():
+				listeners[i] = func(V, E) {
+					v()
+				}
+
+			default:
+				return nil, false
+			}
+		}
+		return listeners, true
+	}
+
+	return nil, false
+}
+
+func valueToEventWithOldListeners[V View, E any](value any) ([]func(V, E, E), bool) {
+	if value == nil {
+		return nil, true
+	}
+
+	switch value := value.(type) {
+	case func(V, E, E):
+		return []func(V, E, E){value}, true
+
+	case func(V, E):
+		fn := func(v V, val, _ E) {
+			value(v, val)
+		}
+		return []func(V, E, E){fn}, true
+
+	case func(E, E):
+		fn := func(_ V, val, old E) {
+			value(val, old)
+		}
+		return []func(V, E, E){fn}, true
+
+	case func(E):
+		fn := func(_ V, val, _ E) {
+			value(val)
+		}
+		return []func(V, E, E){fn}, true
+
+	case func(V):
+		fn := func(v V, _, _ E) {
+			value(v)
+		}
+		return []func(V, E, E){fn}, true
+
+	case func():
+		fn := func(V, E, E) {
+			value()
+		}
+		return []func(V, E, E){fn}, true
+
+	case []func(V, E, E):
+		if len(value) == 0 {
+			return nil, true
+		}
+		for _, fn := range value {
+			if fn == nil {
+				return nil, false
+			}
+		}
+		return value, true
+
+	case []func(V, E):
+		count := len(value)
+		if count == 0 {
+			return nil, true
+		}
+		listeners := make([]func(V, E, E), count)
+		for i, fn := range value {
+			if fn == nil {
+				return nil, false
+			}
+			listeners[i] = func(view V, val, _ E) {
+				fn(view, val)
+			}
+		}
+		return listeners, true
+
+	case []func(E):
+		count := len(value)
+		if count == 0 {
+			return nil, true
+		}
+		listeners := make([]func(V, E, E), count)
+		for i, fn := range value {
+			if fn == nil {
+				return nil, false
+			}
+			listeners[i] = func(_ V, val, _ E) {
+				fn(val)
+			}
+		}
+		return listeners, true
+
+	case []func(E, E):
+		count := len(value)
+		if count == 0 {
+			return nil, true
+		}
+		listeners := make([]func(V, E, E), count)
+		for i, fn := range value {
+			if fn == nil {
+				return nil, false
+			}
+			listeners[i] = func(_ V, val, old E) {
+				fn(val, old)
+			}
+		}
+		return listeners, true
+
+	case []func(V):
+		count := len(value)
+		if count == 0 {
+			return nil, true
+		}
+		listeners := make([]func(V, E, E), count)
+		for i, fn := range value {
+			if fn == nil {
+				return nil, false
+			}
+			listeners[i] = func(view V, _, _ E) {
+				fn(view)
+			}
+		}
+		return listeners, true
+
+	case []func():
+		count := len(value)
+		if count == 0 {
+			return nil, true
+		}
+		listeners := make([]func(V, E, E), count)
+		for i, fn := range value {
+			if fn == nil {
+				return nil, false
+			}
+			listeners[i] = func(V, E, E) {
+				fn()
+			}
+		}
+		return listeners, true
+
+	case []any:
+		count := len(value)
+		if count == 0 {
+			return nil, true
+		}
+		listeners := make([]func(V, E, E), count)
+		for i, v := range value {
+			if v == nil {
+				return nil, false
+			}
+			switch fn := v.(type) {
+			case func(V, E, E):
+				listeners[i] = fn
+
+			case func(V, E):
+				listeners[i] = func(view V, val, _ E) {
+					fn(view, val)
+				}
+
+			case func(E, E):
+				listeners[i] = func(_ V, val, old E) {
+					fn(val, old)
+				}
+
+			case func(E):
+				listeners[i] = func(_ V, val, _ E) {
+					fn(val)
+				}
+
+			case func(V):
+				listeners[i] = func(view V, _, _ E) {
+					fn(view)
+				}
+
+			case func():
+				listeners[i] = func(V, E, E) {
+					fn()
+				}
+
+			default:
+				return nil, false
+			}
+		}
+		return listeners, true
+	}
+
+	return nil, false
+}
+
+func getNoParamEventListeners[V View](view View, subviewID []string, tag PropertyName) []func(V) {
+	if len(subviewID) > 0 && subviewID[0] != "" {
+		view = ViewByID(view, subviewID[0])
+	}
+	if view != nil {
+		if value := view.Get(tag); value != nil {
+			if result, ok := value.([]func(V)); ok {
+				return result
+			}
+		}
+	}
+	return []func(V){}
+}
+
+func getEventListeners[V View, E any](view View, subviewID []string, tag PropertyName) []func(V, E) {
+	if len(subviewID) > 0 && subviewID[0] != "" {
+		view = ViewByID(view, subviewID[0])
+	}
+	if view != nil {
+		if value := view.Get(tag); value != nil {
+			if result, ok := value.([]func(V, E)); ok {
+				return result
+			}
+		}
+	}
+	return []func(V, E){}
+}
+
+func getEventWithOldListeners[V View, E any](view View, subviewID []string, tag PropertyName) []func(V, E, E) {
+	if len(subviewID) > 0 && subviewID[0] != "" {
+		view = ViewByID(view, subviewID[0])
+	}
+	if view != nil {
+		if value := view.Get(tag); value != nil {
+			if result, ok := value.([]func(V, E, E)); ok {
+				return result
+			}
+		}
+	}
+	return []func(V, E, E){}
+}
+
+func setNoParamEventListener[V View](properties Properties, tag PropertyName, value any) []PropertyName {
+	if listeners, ok := valueToNoParamListeners[V](value); ok {
+		if len(listeners) > 0 {
+			properties.setRaw(tag, listeners)
+		} else if properties.getRaw(tag) != nil {
+			properties.setRaw(tag, nil)
+		} else {
+			return []PropertyName{}
+		}
+		return []PropertyName{tag}
+	}
+	notCompatibleType(tag, value)
+	return nil
+}
+
+func setViewEventListener[V View, T any](properties Properties, tag PropertyName, value any) []PropertyName {
+	if listeners, ok := valueToEventListeners[V, T](value); ok {
+		if len(listeners) > 0 {
+			properties.setRaw(tag, listeners)
+		} else if properties.getRaw(tag) != nil {
+			properties.setRaw(tag, nil)
+		} else {
+			return []PropertyName{}
+		}
+		return []PropertyName{tag}
+	}
+	notCompatibleType(tag, value)
+	return nil
+}
+
+func setEventWithOldListener[V View, T any](properties Properties, tag PropertyName, value any) []PropertyName {
+	listeners, ok := valueToEventWithOldListeners[V, T](value)
+	if !ok {
+		notCompatibleType(tag, value)
+		return nil
+	} else if len(listeners) > 0 {
+		properties.setRaw(tag, listeners)
+	} else if properties.getRaw(tag) != nil {
+		properties.setRaw(tag, nil)
+	} else {
+		return []PropertyName{}
+	}
+	return []PropertyName{tag}
+}
+
+func viewEventsHtml[T any](view View, events []PropertyName, buffer *strings.Builder) {
+	for _, tag := range []PropertyName{AnimationStartEvent, AnimationEndEvent, AnimationIterationEvent, AnimationCancelEvent} {
+		if value := view.getRaw(tag); value != nil {
+			if js, ok := eventJsFunc[tag]; ok {
+				if listeners, ok := value.([]func(View, T)); ok && len(listeners) > 0 {
+					buffer.WriteString(js.jsEvent)
+					buffer.WriteString(`="`)
+					buffer.WriteString(js.jsFunc)
+					buffer.WriteString(`(this, event)" `)
+				}
+			}
+		}
+	}
+}
+
+func updateEventListenerHtml(view View, tag PropertyName) {
+	if js, ok := eventJsFunc[tag]; ok {
+		value := view.getRaw(tag)
+		session := view.Session()
+		htmlID := view.htmlID()
+		if value == nil {
+			session.removeProperty(view.htmlID(), js.jsEvent)
+		} else {
+			session.updateProperty(htmlID, js.jsEvent, js.jsFunc+"(this, event)")
+		}
+	}
+}

filePicker.go

@@ -25,7 +25,7 @@ const (
 	// `func(picker rui.FilePicker)`,
 	// `func(files []rui.FileInfo)`,
 	// `func()`.
-	FileSelectedEvent = "file-selected-event"
+	FileSelectedEvent PropertyName = "file-selected-event"
 
 	// Accept is the constant for "accept" property tag.
 	//
@@ -39,7 +39,7 @@ const (
 	// Conversion rules:
 	// `string` - may contain single value of multiple separated by comma(`,`).
 	// `[]string` - an array of acceptable file extensions or MIME types.
-	Accept = "accept"
+	Accept PropertyName = "accept"
 
 	// Multiple is the constant for "multiple" property tag.
 	//
@@ -51,7 +51,7 @@ const (
 	// Values:
 	// `true` or `1` or "true", "yes", "on", "1" - Several files can be selected.
 	// `false` or `0` or "false", "no", "off", "0" - Only one file can be selected.
-	Multiple = "multiple"
+	Multiple PropertyName = "multiple"
 )
 
 // FileInfo describes a file which selected in the FilePicker view
@@ -83,7 +83,6 @@ type FilePicker interface {
 type filePickerData struct {
 	viewData
 	files  []FileInfo
-	fileSelectedListeners []func(FilePicker, []FileInfo)
 	loader map[int]func(FileInfo, []byte)
 }
 
@@ -115,7 +114,7 @@ func NewFilePicker(session Session, params Params) FilePicker {
 }
 
 func newFilePicker(session Session) View {
-	return NewFilePicker(session, nil)
+	return new(filePickerData) // NewFilePicker(session, nil)
 }
 
 func (picker *filePickerData) init(session Session) {
@@ -124,11 +123,9 @@ func (picker *filePickerData) init(session Session) {
 	picker.hasHtmlDisabled = true
 	picker.files = []FileInfo{}
 	picker.loader = map[int]func(FileInfo, []byte){}
-	picker.fileSelectedListeners = []func(FilePicker, []FileInfo){}
+	picker.set = filePickerSet
-}
+	picker.changed = filePickerPropertyChanged
 
-func (picker *filePickerData) String() string {
-	return getViewString(picker, nil)
 }
 
 func (picker *filePickerData) Focusable() bool {
@@ -153,62 +150,27 @@ func (picker *filePickerData) LoadFile(file FileInfo, result func(FileInfo, []by
 	}
 }
 
-func (picker *filePickerData) Remove(tag string) {
+func filePickerSet(view View, tag PropertyName, value any) []PropertyName {
-	picker.remove(strings.ToLower(tag))
-}
 
-func (picker *filePickerData) remove(tag string) {
+	setAccept := func(value string) []PropertyName {
-	switch tag {
+		if value != "" {
-	case FileSelectedEvent:
+			view.setRaw(tag, value)
-		if len(picker.fileSelectedListeners) > 0 {
+		} else if view.getRaw(tag) != nil {
-			picker.fileSelectedListeners = []func(FilePicker, []FileInfo){}
+			view.setRaw(tag, nil)
-			picker.propertyChangedEvent(tag)
+		} else {
+			return []PropertyName{}
 		}
-
+		return []PropertyName{Accept}
-	case Accept:
-		delete(picker.properties, tag)
-		if picker.created {
-			picker.session.removeProperty(picker.htmlID(), "accept")
-		}
-		picker.propertyChangedEvent(tag)
-
-	default:
-		picker.viewData.remove(tag)
-	}
-}
-
-func (picker *filePickerData) Set(tag string, value any) bool {
-	return picker.set(strings.ToLower(tag), value)
-}
-
-func (picker *filePickerData) set(tag string, value any) bool {
-	if value == nil {
-		picker.remove(tag)
-		return true
 	}
 
 	switch tag {
 	case FileSelectedEvent:
-		listeners, ok := valueToEventListeners[FilePicker, []FileInfo](value)
+		return setViewEventListener[FilePicker, []FileInfo](view, tag, value)
-		if !ok {
-			notCompatibleType(tag, value)
-			return false
-		} else if listeners == nil {
-			listeners = []func(FilePicker, []FileInfo){}
-		}
-		picker.fileSelectedListeners = listeners
-		picker.propertyChangedEvent(tag)
-		return true
 
 	case Accept:
 		switch value := value.(type) {
 		case string:
-			value = strings.Trim(value, " \t\n")
+			return setAccept(strings.Trim(value, " \t\n"))
-			if value == "" {
-				picker.remove(Accept)
-			} else {
-				picker.properties[Accept] = value
-			}
 
 		case []string:
 			buffer := allocStringBuilder()
@@ -222,29 +184,27 @@ func (picker *filePickerData) set(tag string, value any) bool {
 					buffer.WriteString(val)
 				}
 			}
-			if buffer.Len() == 0 {
+			return setAccept(buffer.String())
-				picker.remove(Accept)
-			} else {
-				picker.properties[Accept] = buffer.String()
 		}
-
-		default:
 		notCompatibleType(tag, value)
-			return false
+		return nil
 	}
 
-		if picker.created {
+	return viewSet(view, tag, value)
-			if css := picker.acceptCSS(); css != "" {
+}
-				picker.session.updateProperty(picker.htmlID(), "accept", css)
+
+func filePickerPropertyChanged(view View, tag PropertyName) {
+	switch tag {
+	case Accept:
+		session := view.Session()
+		if css := acceptPropertyCSS(view); css != "" {
+			session.updateProperty(view.htmlID(), "accept", css)
 		} else {
-				picker.session.removeProperty(picker.htmlID(), "accept")
+			session.removeProperty(view.htmlID(), "accept")
 		}
-		}
-		picker.propertyChangedEvent(tag)
-		return true
 
 	default:
-		return picker.viewData.set(tag, value)
+		viewPropertyChanged(view, tag)
 	}
 }
 
@@ -252,10 +212,10 @@ func (picker *filePickerData) htmlTag() string {
 	return "input"
 }
 
-func (picker *filePickerData) acceptCSS() string {
+func acceptPropertyCSS(view View) string {
-	accept, ok := stringProperty(picker, Accept, picker.Session())
+	accept, ok := stringProperty(view, Accept, view.Session())
 	if !ok {
-		if value := valueFromStyle(picker, Accept); value != nil {
+		if value := valueFromStyle(view, Accept); value != nil {
 			accept, ok = value.(string)
 		}
 	}
@@ -282,7 +242,7 @@ func (picker *filePickerData) acceptCSS() string {
 func (picker *filePickerData) htmlProperties(self View, buffer *strings.Builder) {
 	picker.viewData.htmlProperties(self, buffer)
 
-	if accept := picker.acceptCSS(); accept != "" {
+	if accept := acceptPropertyCSS(picker); accept != "" {
 		buffer.WriteString(` accept="`)
 		buffer.WriteString(accept)
 		buffer.WriteRune('"')
@@ -299,7 +259,7 @@ func (picker *filePickerData) htmlProperties(self View, buffer *strings.Builder)
 	}
 }
 
-func (picker *filePickerData) handleCommand(self View, command string, data DataObject) bool {
+func (picker *filePickerData) handleCommand(self View, command PropertyName, data DataObject) bool {
 	switch command {
 	case "fileSelected":
 		if node := data.PropertyByTag("files"); node != nil && node.Type() == ArrayNode {
@@ -312,7 +272,7 @@ func (picker *filePickerData) handleCommand(self View, command string, data Data
 			}
 			picker.files = files
 
-			for _, listener := range picker.fileSelectedListeners {
+			for _, listener := range GetFileSelectedListeners(picker) {
 				listener(picker, files)
 			}
 		}

focusEvents.go

@@ -17,7 +17,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	FocusEvent = "focus-event"
+	FocusEvent PropertyName = "focus-event"
 
 	// LostFocusEvent is the constant for "lost-focus-event" property tag.
 	//
@@ -32,132 +32,13 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	LostFocusEvent = "lost-focus-event"
+	LostFocusEvent PropertyName = "lost-focus-event"
 )
 
-func valueToNoParamListeners[V any](value any) ([]func(V), bool) {
-	if value == nil {
-		return nil, true
-	}
-
-	switch value := value.(type) {
-	case func(V):
-		return []func(V){value}, true
-
-	case func():
-		fn := func(V) {
-			value()
-		}
-		return []func(V){fn}, true
-
-	case []func(V):
-		if len(value) == 0 {
-			return nil, true
-		}
-		for _, fn := range value {
-			if fn == nil {
-				return nil, false
-			}
-		}
-		return value, true
-
-	case []func():
-		count := len(value)
-		if count == 0 {
-			return nil, true
-		}
-		listeners := make([]func(V), count)
-		for i, v := range value {
-			if v == nil {
-				return nil, false
-			}
-			listeners[i] = func(V) {
-				v()
-			}
-		}
-		return listeners, true
-
-	case []any:
-		count := len(value)
-		if count == 0 {
-			return nil, true
-		}
-		listeners := make([]func(V), count)
-		for i, v := range value {
-			if v == nil {
-				return nil, false
-			}
-			switch v := v.(type) {
-			case func(V):
-				listeners[i] = v
-
-			case func():
-				listeners[i] = func(V) {
-					v()
-				}
-
-			default:
-				return nil, false
-			}
-		}
-		return listeners, true
-	}
-
-	return nil, false
-}
-
-var focusEvents = map[string]struct{ jsEvent, jsFunc string }{
-	FocusEvent:     {jsEvent: "onfocus", jsFunc: "focusEvent"},
-	LostFocusEvent: {jsEvent: "onblur", jsFunc: "blurEvent"},
-}
-
-func (view *viewData) setFocusListener(tag string, value any) bool {
-	listeners, ok := valueToNoParamListeners[View](value)
-	if !ok {
-		notCompatibleType(tag, value)
-		return false
-	}
-
-	if listeners == nil {
-		view.removeFocusListener(tag)
-	} else if js, ok := focusEvents[tag]; ok {
-		view.properties[tag] = listeners
-		if view.created {
-			view.session.updateProperty(view.htmlID(), js.jsEvent, js.jsFunc+"(this, event)")
-		}
-	} else {
-		return false
-	}
-	return true
-}
-
-func (view *viewData) removeFocusListener(tag string) {
-	delete(view.properties, tag)
-	if view.created {
-		if js, ok := focusEvents[tag]; ok {
-			view.session.removeProperty(view.htmlID(), js.jsEvent)
-		}
-	}
-}
-
-func getFocusListeners(view View, subviewID []string, tag string) []func(View) {
-	if len(subviewID) > 0 && subviewID[0] != "" {
-		view = ViewByID(view, subviewID[0])
-	}
-
-	if view != nil {
-		if value := view.Get(tag); value != nil {
-			if result, ok := value.([]func(View)); ok {
-				return result
-			}
-		}
-	}
-	return []func(View){}
-}
-
 func focusEventsHtml(view View, buffer *strings.Builder) {
 	if view.Focusable() {
-		for _, js := range focusEvents {
+		for _, tag := range []PropertyName{FocusEvent, LostFocusEvent} {
+			if js, ok := eventJsFunc[tag]; ok {
 				buffer.WriteString(js.jsEvent)
 				buffer.WriteString(`="`)
 				buffer.WriteString(js.jsFunc)
@@ -165,15 +46,16 @@ func focusEventsHtml(view View, buffer *strings.Builder) {
 			}
 		}
 	}
+}
 
 // GetFocusListeners returns a FocusListener list. If there are no listeners then the empty list is returned
 // If the second argument (subviewID) is not specified or it is "" then a value from the first argument (view) is returned.
 func GetFocusListeners(view View, subviewID ...string) []func(View) {
-	return getFocusListeners(view, subviewID, FocusEvent)
+	return getNoParamEventListeners[View](view, subviewID, FocusEvent)
 }
 
 // GetLostFocusListeners returns a LostFocusListener list. If there are no listeners then the empty list is returned
 // If the second argument (subviewID) is not specified or it is "" then a value from the first argument (view) is returned.
 func GetLostFocusListeners(view View, subviewID ...string) []func(View) {
-	return getFocusListeners(view, subviewID, LostFocusEvent)
+	return getNoParamEventListeners[View](view, subviewID, LostFocusEvent)
 }

gridLayout.go

@@ -24,7 +24,7 @@ const (
 	//
 	// Usage in `SvgImageView`:
 	// Same as "vertical-align".
-	CellVerticalAlign = "cell-vertical-align"
+	CellVerticalAlign PropertyName = "cell-vertical-align"
 
 	// CellHorizontalAlign is the constant for "cell-horizontal-align" property tag.
 	//
@@ -43,7 +43,7 @@ const (
 	//
 	// Usage in `SvgImageView`:
 	// Same as "horizontal-align".
-	CellHorizontalAlign = "cell-horizontal-align"
+	CellHorizontalAlign PropertyName = "cell-horizontal-align"
 
 	// CellVerticalSelfAlign is the constant for "cell-vertical-self-align" property tag.
 	//
@@ -58,7 +58,7 @@ const (
 	// `1`(`BottomAlign`) or "bottom" - Bottom alignment.
 	// `2`(`CenterAlign`) or "center" - Center alignment.
 	// `3`(`StretchAlign`) or "stretch" - Full height stretch.
-	CellVerticalSelfAlign = "cell-vertical-self-align"
+	CellVerticalSelfAlign PropertyName = "cell-vertical-self-align"
 
 	// CellHorizontalSelfAlign is the constant for "cell-horizontal-self-align" property tag.
 	//
@@ -73,7 +73,7 @@ const (
 	// `1`(`RightAlign`) or "right" - Right alignment.
 	// `2`(`CenterAlign`) or "center" - Center alignment.
 	// `3`(`StretchAlign`) or "stretch" - Full width stretch.
-	CellHorizontalSelfAlign = "cell-horizontal-self-align"
+	CellHorizontalSelfAlign PropertyName = "cell-horizontal-self-align"
 )
 
 // GridAdapter is an interface to define [GridLayout] content. [GridLayout] will query interface functions to populate
@@ -126,7 +126,8 @@ func NewGridLayout(session Session, params Params) GridLayout {
 }
 
 func newGridLayout(session Session) View {
-	return NewGridLayout(session, nil)
+	//return NewGridLayout(session, nil)
+	return new(gridLayoutData)
 }
 
 // Init initialize fields of GridLayout by default values
@@ -135,13 +136,14 @@ func (gridLayout *gridLayoutData) init(session Session) {
 	gridLayout.tag = "GridLayout"
 	gridLayout.systemClass = "ruiGridLayout"
 	gridLayout.adapter = nil
+	gridLayout.normalize = normalizeGridLayoutTag
+	gridLayout.getFunc = gridLayout.get
+	gridLayout.set = gridLayout.setFunc
+	gridLayout.remove = gridLayout.removeFunc
+
 }
 
-func (gridLayout *gridLayoutData) String() string {
+func setGridCellSize(properties Properties, tag PropertyName, value any) []PropertyName {
-	return getViewString(gridLayout, nil)
-}
-
-func (style *viewStyle) setGridCellSize(tag string, value any) bool {
 	setValues := func(values []string) bool {
 		count := len(values)
 		if count > 1 {
@@ -159,11 +161,11 @@ func (style *viewStyle) setGridCellSize(tag string, value any) bool {
 					return false
 				}
 			}
-			style.properties[tag] = sizes
+			properties.setRaw(tag, sizes)
 		} else if isConstantName(values[0]) {
-			style.properties[tag] = values[0]
+			properties.setRaw(tag, values[0])
 		} else if size, err := stringToSizeUnit(values[0]); err == nil {
-			style.properties[tag] = size
+			properties.setRaw(tag, size)
 		} else {
 			invalidPropertyValue(tag, value)
 			return false
@@ -175,41 +177,41 @@ func (style *viewStyle) setGridCellSize(tag string, value any) bool {
 	case CellWidth, CellHeight:
 		switch value := value.(type) {
 		case SizeUnit, []SizeUnit:
-			style.properties[tag] = value
+			properties.setRaw(tag, value)
 
 		case string:
 			if !setValues(strings.Split(value, ",")) {
-				return false
+				return nil
 			}
 
 		case []string:
 			if !setValues(value) {
-				return false
+				return nil
 			}
 
 		case []DataValue:
 			count := len(value)
 			if count == 0 {
 				invalidPropertyValue(tag, value)
-				return false
+				return nil
 			}
 			values := make([]string, count)
 			for i, val := range value {
 				if val.IsObject() {
 					invalidPropertyValue(tag, value)
-					return false
+					return nil
 				}
 				values[i] = val.Value()
 			}
 			if !setValues(values) {
-				return false
+				return nil
 			}
 
 		case []any:
 			count := len(value)
 			if count == 0 {
 				invalidPropertyValue(tag, value)
-				return false
+				return nil
 			}
 			sizes := make([]any, count)
 			for i, val := range value {
@@ -224,29 +226,29 @@ func (style *viewStyle) setGridCellSize(tag string, value any) bool {
 						sizes[i] = size
 					} else {
 						invalidPropertyValue(tag, value)
-						return false
+						return nil
 					}
 
 				default:
 					invalidPropertyValue(tag, value)
-					return false
+					return nil
 				}
 			}
-			style.properties[tag] = sizes
+			properties.setRaw(tag, sizes)
 
 		default:
 			notCompatibleType(tag, value)
-			return false
+			return nil
 		}
 
-		return true
+		return []PropertyName{tag}
 	}
 
-	return false
+	return nil
 }
 
-func (style *viewStyle) gridCellSizesCSS(tag string, session Session) string {
+func gridCellSizesCSS(properties Properties, tag PropertyName, session Session) string {
-	switch cellSize := gridCellSizes(style, tag, session); len(cellSize) {
+	switch cellSize := gridCellSizes(properties, tag, session); len(cellSize) {
 	case 0:
 
 	case 1:
@@ -283,8 +285,8 @@ func (style *viewStyle) gridCellSizesCSS(tag string, session Session) string {
 	return ""
 }
 
-func (gridLayout *gridLayoutData) normalizeTag(tag string) string {
+func normalizeGridLayoutTag(tag PropertyName) PropertyName {
-	tag = strings.ToLower(tag)
+	tag = defaultNormalize(tag)
 	switch tag {
 	case VerticalAlign:
 		return CellVerticalAlign
@@ -301,99 +303,97 @@ func (gridLayout *gridLayoutData) normalizeTag(tag string) string {
 	return tag
 }
 
-func (gridLayout *gridLayoutData) Get(tag string) any {
+func (gridLayout *gridLayoutData) get(self View, tag PropertyName) any {
-	return gridLayout.get(gridLayout.normalizeTag(tag))
+	switch tag {
-}
+	case Gap:
-
-func (gridLayout *gridLayoutData) get(tag string) any {
-	if tag == Gap {
 		rowGap := GetGridRowGap(gridLayout)
 		columnGap := GetGridColumnGap(gridLayout)
 		if rowGap.Equal(columnGap) {
 			return rowGap
 		}
 		return AutoSize()
-	}
-
-	return gridLayout.viewsContainerData.get(tag)
-}
-
-func (gridLayout *gridLayoutData) Remove(tag string) {
-	gridLayout.remove(gridLayout.normalizeTag(tag))
-}
-
-func (gridLayout *gridLayoutData) remove(tag string) {
-	switch tag {
-	case Gap:
-		gridLayout.remove(GridRowGap)
-		gridLayout.remove(GridColumnGap)
-		gridLayout.propertyChangedEvent(Gap)
-		return
 
 	case Content:
-		gridLayout.adapter = nil
+		if gridLayout.adapter != nil {
-	}
+			return gridLayout.adapter
-
-	gridLayout.viewsContainerData.remove(tag)
-
-	if gridLayout.created {
-		switch tag {
-		case CellWidth:
-			gridLayout.session.updateCSSProperty(gridLayout.htmlID(), `grid-template-columns`,
-				gridLayout.gridCellSizesCSS(CellWidth, gridLayout.session))
-
-		case CellHeight:
-			gridLayout.session.updateCSSProperty(gridLayout.htmlID(), `grid-template-rows`,
-				gridLayout.gridCellSizesCSS(CellHeight, gridLayout.session))
-
 		}
 	}
+
+	return gridLayout.viewsContainerData.get(gridLayout, tag)
 }
 
-func (gridLayout *gridLayoutData) Set(tag string, value any) bool {
+func (gridLayout *gridLayoutData) removeFunc(self View, tag PropertyName) []PropertyName {
-	return gridLayout.set(gridLayout.normalizeTag(tag), value)
-}
-
-func (gridLayout *gridLayoutData) set(tag string, value any) bool {
-	if value == nil {
-		gridLayout.remove(tag)
-		return true
-	}
-
 	switch tag {
 	case Gap:
-		return gridLayout.set(GridRowGap, value) && gridLayout.set(GridColumnGap, value)
+		result := []PropertyName{}
+		for _, tag := range []PropertyName{GridRowGap, GridColumnGap} {
+			if gridLayout.getRaw(tag) != nil {
+				gridLayout.setRaw(tag, nil)
+				result = append(result, tag)
+			}
+		}
+		return result
+
+	case Content:
+		if len(gridLayout.views) > 0 || gridLayout.adapter != nil {
+			gridLayout.views = []View{}
+			gridLayout.adapter = nil
+			return []PropertyName{Content}
+		}
+		return []PropertyName{}
+	}
+
+	return gridLayout.viewsContainerData.removeFunc(gridLayout, tag)
+}
+
+func (gridLayout *gridLayoutData) setFunc(self View, tag PropertyName, value any) []PropertyName {
+	switch tag {
+	case Gap:
+		result := gridLayout.setFunc(gridLayout, GridRowGap, value)
+		if result != nil {
+			if gap := gridLayout.getRaw(GridRowGap); gap != nil {
+				gridLayout.setRaw(GridColumnGap, gap)
+				result = append(result, GridColumnGap)
+			}
+		}
+		return result
 
 	case Content:
 		if adapter, ok := value.(GridAdapter); ok {
 			gridLayout.adapter = adapter
-			gridLayout.UpdateGridContent()
+			gridLayout.createGridContent()
-			return true
+		} else if gridLayout.setContent(value) {
-		}
 			gridLayout.adapter = nil
+		} else {
+			return nil
+		}
+		return []PropertyName{Content}
 	}
 
-	if gridLayout.viewsContainerData.set(tag, value) {
+	return gridLayout.viewsContainerData.setFunc(gridLayout, tag, value)
-		if gridLayout.created {
+}
+
+func gridLayoutPropertyChanged(view View, tag PropertyName) {
 	switch tag {
 	case CellWidth:
-				gridLayout.session.updateCSSProperty(gridLayout.htmlID(), `grid-template-columns`,
+		view.Session().updateCSSProperty(view.htmlID(), `grid-template-columns`,
-					gridLayout.gridCellSizesCSS(CellWidth, gridLayout.session))
+			gridCellSizesCSS(view, CellWidth, view.Session()))
 
 	case CellHeight:
-				gridLayout.session.updateCSSProperty(gridLayout.htmlID(), `grid-template-rows`,
+		view.Session().updateCSSProperty(view.htmlID(), `grid-template-rows`,
-					gridLayout.gridCellSizesCSS(CellHeight, gridLayout.session))
+			gridCellSizesCSS(view, CellHeight, view.Session()))
 
+	default:
+		viewsContainerPropertyChanged(view, tag)
 	}
 }
-		return true
-	}
 
+func (gridLayout *gridLayoutData) createGridContent() bool {
+	if gridLayout.adapter == nil {
 		return false
 	}
 
-func (gridLayout *gridLayoutData) UpdateGridContent() {
+	adapter := gridLayout.adapter
-	if adapter := gridLayout.adapter; adapter != nil {
 	gridLayout.views = []View{}
 
 	session := gridLayout.session
@@ -448,15 +448,22 @@ func (gridLayout *gridLayoutData) UpdateGridContent() {
 		}
 	}
 
+	return true
+}
+
+func (gridLayout *gridLayoutData) UpdateGridContent() {
+	if gridLayout.createGridContent() {
 		if gridLayout.created {
-			updateInnerHTML(htmlID, session)
+			updateInnerHTML(gridLayout.htmlID(), gridLayout.session)
 		}
 
-		gridLayout.propertyChangedEvent(Content)
+		if listener, ok := gridLayout.changeListener[Content]; ok {
+			listener(gridLayout, Content)
+		}
 	}
 }
 
-func gridCellSizes(properties Properties, tag string, session Session) []SizeUnit {
+func gridCellSizes(properties Properties, tag PropertyName, session Session) []SizeUnit {
 	if value := properties.Get(tag); value != nil {
 		switch value := value.(type) {
 		case []SizeUnit:

imageView.go

@@ -20,7 +20,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	LoadedEvent = "loaded-event"
+	LoadedEvent PropertyName = "loaded-event"
 
 	// ErrorEvent is the constant for "error-event" property tag.
 	//
@@ -35,7 +35,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	ErrorEvent = "error-event"
+	ErrorEvent PropertyName = "error-event"
 
 	// NoneFit - value of the "object-fit" property of an ImageView. The replaced content is not resized
 	NoneFit = 0
@@ -88,7 +88,7 @@ func NewImageView(session Session, params Params) ImageView {
 }
 
 func newImageView(session Session) View {
-	return NewImageView(session, nil)
+	return new(imageViewData)
 }
 
 // Init initialize fields of imageView by default values
@@ -96,14 +96,13 @@ func (imageView *imageViewData) init(session Session) {
 	imageView.viewData.init(session)
 	imageView.tag = "ImageView"
 	imageView.systemClass = "ruiImageView"
+	imageView.normalize = normalizeImageViewTag
+	imageView.set = imageViewSet
+	imageView.changed = imageViewPropertyChanged
 }
 
-func (imageView *imageViewData) String() string {
+func normalizeImageViewTag(tag PropertyName) PropertyName {
-	return getViewString(imageView, nil)
+	tag = defaultNormalize(tag)
-}
-
-func (imageView *imageViewData) normalizeTag(tag string) string {
-	tag = strings.ToLower(tag)
 	switch tag {
 	case "source":
 		tag = Source
@@ -123,127 +122,58 @@ func (imageView *imageViewData) normalizeTag(tag string) string {
 	return tag
 }
 
-func (imageView *imageViewData) Remove(tag string) {
+func imageViewSet(view View, tag PropertyName, value any) []PropertyName {
-	imageView.remove(imageView.normalizeTag(tag))
-}
-
-func (imageView *imageViewData) remove(tag string) {
-	imageView.viewData.remove(tag)
-	if imageView.created {
-		switch tag {
-		case Source:
-			imageView.session.updateProperty(imageView.htmlID(), "src", "")
-			imageView.session.removeProperty(imageView.htmlID(), "srcset")
-
-		case AltText:
-			updateInnerHTML(imageView.htmlID(), imageView.session)
-
-		case ImageVerticalAlign, ImageHorizontalAlign:
-			updateCSSStyle(imageView.htmlID(), imageView.session)
-		}
-	}
-}
-
-func (imageView *imageViewData) Set(tag string, value any) bool {
-	return imageView.set(imageView.normalizeTag(tag), value)
-}
-
-func (imageView *imageViewData) set(tag string, value any) bool {
-	if value == nil {
-		imageView.remove(tag)
-		return true
-	}
 
 	switch tag {
-	case Source:
+	case Source, SrcSet, AltText:
 		if text, ok := value.(string); ok {
-			imageView.properties[tag] = text
+			return setStringPropertyValue(view, tag, text)
-			if imageView.created {
-				src, srcset := imageView.src(text)
-				imageView.session.updateProperty(imageView.htmlID(), "src", src)
-
-				if srcset != "" {
-					imageView.session.updateProperty(imageView.htmlID(), "srcset", srcset)
-				} else {
-					imageView.session.removeProperty(imageView.htmlID(), "srcset")
-				}
-			}
-			imageView.propertyChangedEvent(Source)
-			return true
-		}
-		notCompatibleType(Source, value)
-
-	case SrcSet:
-		if text, ok := value.(string); ok {
-			if text == "" {
-				delete(imageView.properties, tag)
-			} else {
-				imageView.properties[tag] = text
-			}
-			if imageView.created {
-				_, srcset := imageView.src(text)
-				if srcset != "" {
-					imageView.session.updateProperty(imageView.htmlID(), "srcset", srcset)
-				} else {
-					imageView.session.removeProperty(imageView.htmlID(), "srcset")
-				}
-			}
-			imageView.propertyChangedEvent(Source)
-			return true
-		}
-		notCompatibleType(Source, value)
-
-	case AltText:
-		if text, ok := value.(string); ok {
-			imageView.properties[AltText] = text
-			if imageView.created {
-				updateInnerHTML(imageView.htmlID(), imageView.session)
-			}
-			imageView.propertyChangedEvent(Source)
-			return true
 		}
 		notCompatibleType(tag, value)
+		return nil
 
 	case LoadedEvent, ErrorEvent:
-		if listeners, ok := valueToNoParamListeners[ImageView](value); ok {
+		return setNoParamEventListener[ImageView](view, tag, value)
-			if listeners == nil {
+	}
-				delete(imageView.properties, tag)
+
+	return viewSet(view, tag, value)
+}
+
+func imageViewPropertyChanged(view View, tag PropertyName) {
+	session := view.Session()
+	htmlID := view.htmlID()
+
+	switch tag {
+	case Source:
+		src, srcset := imageViewSrc(view, GetImageViewSource(view))
+		session.updateProperty(htmlID, "src", src)
+		if srcset != "" {
+			session.updateProperty(htmlID, "srcset", srcset)
 		} else {
-				imageView.properties[tag] = listeners
+			session.removeProperty(htmlID, "srcset")
 		}
-			return true
+
+	case SrcSet:
+		_, srcset := imageViewSrc(view, GetImageViewSource(view))
+		if srcset != "" {
+			session.updateProperty(htmlID, "srcset", srcset)
+		} else {
+			session.removeProperty(htmlID, "srcset")
 		}
 
+	case AltText:
+		updateInnerHTML(htmlID, session)
+
+	case ImageVerticalAlign, ImageHorizontalAlign:
+		updateCSSStyle(htmlID, session)
+
 	default:
-		if imageView.viewData.set(tag, value) {
+		viewPropertyChanged(view, tag)
-			if imageView.created {
-				switch tag {
-				case ImageVerticalAlign, ImageHorizontalAlign:
-					updateCSSStyle(imageView.htmlID(), imageView.session)
-				}
-			}
-			return true
 	}
 }
 
-	return false
+func imageViewSrcSet(view View, path string) string {
-}
+	if value := view.getRaw(SrcSet); value != nil {
-
-func (imageView *imageViewData) Get(tag string) any {
-	return imageView.viewData.get(imageView.normalizeTag(tag))
-}
-
-func (imageView *imageViewData) imageListeners(tag string) []func(ImageView) {
-	if value := imageView.getRaw(tag); value != nil {
-		if listeners, ok := value.([]func(ImageView)); ok {
-			return listeners
-		}
-	}
-	return []func(ImageView){}
-}
-
-func (imageView *imageViewData) srcSet(path string) string {
-	if value := imageView.getRaw(SrcSet); value != nil {
 		if text, ok := value.(string); ok {
 			srcset := strings.Split(text, ",")
 			buffer := allocStringBuilder()
@@ -286,9 +216,9 @@ func (imageView *imageViewData) htmlTag() string {
 	return "img"
 }
 
-func (imageView *imageViewData) src(src string) (string, string) {
+func imageViewSrc(view View, src string) (string, string) {
 	if src != "" && src[0] == '@' {
-		if image, ok := imageView.Session().ImageConstant(src[1:]); ok {
+		if image, ok := view.Session().ImageConstant(src[1:]); ok {
 			src = image
 		} else {
 			src = ""
@@ -296,7 +226,7 @@ func (imageView *imageViewData) src(src string) (string, string) {
 	}
 
 	if src != "" {
-		return src, imageView.srcSet(src)
+		return src, imageViewSrcSet(view, src)
 	}
 	return "", ""
 }
@@ -306,7 +236,7 @@ func (imageView *imageViewData) htmlProperties(self View, buffer *strings.Builde
 	imageView.viewData.htmlProperties(self, buffer)
 
 	if imageResource, ok := imageProperty(imageView, Source, imageView.Session()); ok && imageResource != "" {
-		if src, srcset := imageView.src(imageResource); src != "" {
+		if src, srcset := imageViewSrc(imageView, imageResource); src != "" {
 			buffer.WriteString(` src="`)
 			buffer.WriteString(src)
 			buffer.WriteString(`"`)
@@ -326,7 +256,7 @@ func (imageView *imageViewData) htmlProperties(self View, buffer *strings.Builde
 
 	buffer.WriteString(` onload="imageLoaded(this, event)"`)
 
-	if len(imageView.imageListeners(ErrorEvent)) > 0 {
+	if len(getNoParamEventListeners[ImageView](imageView, nil, ErrorEvent)) > 0 {
 		buffer.WriteString(` onerror="imageError(this, event)"`)
 	}
 }
@@ -366,10 +296,10 @@ func (imageView *imageViewData) cssStyle(self View, builder cssBuilder) {
 	}
 }
 
-func (imageView *imageViewData) handleCommand(self View, command string, data DataObject) bool {
+func (imageView *imageViewData) handleCommand(self View, command PropertyName, data DataObject) bool {
 	switch command {
 	case "imageViewError":
-		for _, listener := range imageView.imageListeners(ErrorEvent) {
+		for _, listener := range getNoParamEventListeners[ImageView](imageView, nil, ErrorEvent) {
 			listener(imageView)
 		}
 
@@ -378,7 +308,7 @@ func (imageView *imageViewData) handleCommand(self View, command string, data Da
 		imageView.naturalHeight = dataFloatProperty(data, "natural-height")
 		imageView.currentSrc, _ = data.PropertyValue("current-src")
 
-		for _, listener := range imageView.imageListeners(LoadedEvent) {
+		for _, listener := range getNoParamEventListeners[ImageView](imageView, nil, LoadedEvent) {
 			listener(imageView)
 		}
 

keyEvents.go

@@ -20,7 +20,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(event rui.KeyEvent)`,
 	// `func()`.
-	KeyDownEvent = "key-down-event"
+	KeyDownEvent PropertyName = "key-down-event"
 
 	// KeyUpEvent is the constant for "key-up-event" property tag.
 	//
@@ -38,7 +38,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(event rui.KeyEvent)`,
 	// `func()`.
-	KeyUpEvent = "key-up-event"
+	KeyUpEvent PropertyName = "key-up-event"
 )
 
 // ControlKeyMask represent ORed state of keyboard's control keys like [AltKey], [CtrlKey], [ShiftKey] and [MetaKey]
@@ -429,342 +429,21 @@ func (event *KeyEvent) init(data DataObject) {
 	event.MetaKey = getBool("metaKey")
 }
 
-func valueToEventListeners[V View, E any](value any) ([]func(V, E), bool) {
+/*
-	if value == nil {
+func setKeyListener(properties Properties, tag PropertyName, value any) bool {
-		return nil, true
+	if listeners, ok := valueToEventListeners[View, KeyEvent](value); ok {
+		if len(listeners) == 0 {
+			properties.setRaw(tag, nil)
+		} else {
+			properties.setRaw(tag, listeners)
 		}
-
+		return true
-	switch value := value.(type) {
-	case func(V, E):
-		return []func(V, E){value}, true
-
-	case func(E):
-		fn := func(_ V, event E) {
-			value(event)
 	}
-		return []func(V, E){fn}, true
-
-	case func(V):
-		fn := func(view V, _ E) {
-			value(view)
-		}
-		return []func(V, E){fn}, true
-
-	case func():
-		fn := func(V, E) {
-			value()
-		}
-		return []func(V, E){fn}, true
-
-	case []func(V, E):
-		if len(value) == 0 {
-			return nil, true
-		}
-		for _, fn := range value {
-			if fn == nil {
-				return nil, false
-			}
-		}
-		return value, true
-
-	case []func(E):
-		count := len(value)
-		if count == 0 {
-			return nil, true
-		}
-		listeners := make([]func(V, E), count)
-		for i, v := range value {
-			if v == nil {
-				return nil, false
-			}
-			listeners[i] = func(_ V, event E) {
-				v(event)
-			}
-		}
-		return listeners, true
-
-	case []func(V):
-		count := len(value)
-		if count == 0 {
-			return nil, true
-		}
-		listeners := make([]func(V, E), count)
-		for i, v := range value {
-			if v == nil {
-				return nil, false
-			}
-			listeners[i] = func(view V, _ E) {
-				v(view)
-			}
-		}
-		return listeners, true
-
-	case []func():
-		count := len(value)
-		if count == 0 {
-			return nil, true
-		}
-		listeners := make([]func(V, E), count)
-		for i, v := range value {
-			if v == nil {
-				return nil, false
-			}
-			listeners[i] = func(V, E) {
-				v()
-			}
-		}
-		return listeners, true
-
-	case []any:
-		count := len(value)
-		if count == 0 {
-			return nil, true
-		}
-		listeners := make([]func(V, E), count)
-		for i, v := range value {
-			if v == nil {
-				return nil, false
-			}
-			switch v := v.(type) {
-			case func(V, E):
-				listeners[i] = v
-
-			case func(E):
-				listeners[i] = func(_ V, event E) {
-					v(event)
-				}
-
-			case func(V):
-				listeners[i] = func(view V, _ E) {
-					v(view)
-				}
-
-			case func():
-				listeners[i] = func(V, E) {
-					v()
-				}
-
-			default:
-				return nil, false
-			}
-		}
-		return listeners, true
-	}
-
-	return nil, false
-}
-
-func valueToEventWithOldListeners[V View, E any](value any) ([]func(V, E, E), bool) {
-	if value == nil {
-		return nil, true
-	}
-
-	switch value := value.(type) {
-	case func(V, E, E):
-		return []func(V, E, E){value}, true
-
-	case func(V, E):
-		fn := func(v V, val, _ E) {
-			value(v, val)
-		}
-		return []func(V, E, E){fn}, true
-
-	case func(E, E):
-		fn := func(_ V, val, old E) {
-			value(val, old)
-		}
-		return []func(V, E, E){fn}, true
-
-	case func(E):
-		fn := func(_ V, val, _ E) {
-			value(val)
-		}
-		return []func(V, E, E){fn}, true
-
-	case func(V):
-		fn := func(v V, _, _ E) {
-			value(v)
-		}
-		return []func(V, E, E){fn}, true
-
-	case func():
-		fn := func(V, E, E) {
-			value()
-		}
-		return []func(V, E, E){fn}, true
-
-	case []func(V, E, E):
-		if len(value) == 0 {
-			return nil, true
-		}
-		for _, fn := range value {
-			if fn == nil {
-				return nil, false
-			}
-		}
-		return value, true
-
-	case []func(V, E):
-		count := len(value)
-		if count == 0 {
-			return nil, true
-		}
-		listeners := make([]func(V, E, E), count)
-		for i, fn := range value {
-			if fn == nil {
-				return nil, false
-			}
-			listeners[i] = func(view V, val, _ E) {
-				fn(view, val)
-			}
-		}
-		return listeners, true
-
-	case []func(E):
-		count := len(value)
-		if count == 0 {
-			return nil, true
-		}
-		listeners := make([]func(V, E, E), count)
-		for i, fn := range value {
-			if fn == nil {
-				return nil, false
-			}
-			listeners[i] = func(_ V, val, _ E) {
-				fn(val)
-			}
-		}
-		return listeners, true
-
-	case []func(E, E):
-		count := len(value)
-		if count == 0 {
-			return nil, true
-		}
-		listeners := make([]func(V, E, E), count)
-		for i, fn := range value {
-			if fn == nil {
-				return nil, false
-			}
-			listeners[i] = func(_ V, val, old E) {
-				fn(val, old)
-			}
-		}
-		return listeners, true
-
-	case []func(V):
-		count := len(value)
-		if count == 0 {
-			return nil, true
-		}
-		listeners := make([]func(V, E, E), count)
-		for i, fn := range value {
-			if fn == nil {
-				return nil, false
-			}
-			listeners[i] = func(view V, _, _ E) {
-				fn(view)
-			}
-		}
-		return listeners, true
-
-	case []func():
-		count := len(value)
-		if count == 0 {
-			return nil, true
-		}
-		listeners := make([]func(V, E, E), count)
-		for i, fn := range value {
-			if fn == nil {
-				return nil, false
-			}
-			listeners[i] = func(V, E, E) {
-				fn()
-			}
-		}
-		return listeners, true
-
-	case []any:
-		count := len(value)
-		if count == 0 {
-			return nil, true
-		}
-		listeners := make([]func(V, E, E), count)
-		for i, v := range value {
-			if v == nil {
-				return nil, false
-			}
-			switch fn := v.(type) {
-			case func(V, E, E):
-				listeners[i] = fn
-
-			case func(V, E):
-				listeners[i] = func(view V, val, _ E) {
-					fn(view, val)
-				}
-
-			case func(E, E):
-				listeners[i] = func(_ V, val, old E) {
-					fn(val, old)
-				}
-
-			case func(E):
-				listeners[i] = func(_ V, val, _ E) {
-					fn(val)
-				}
-
-			case func(V):
-				listeners[i] = func(view V, _, _ E) {
-					fn(view)
-				}
-
-			case func():
-				listeners[i] = func(V, E, E) {
-					fn()
-				}
-
-			default:
-				return nil, false
-			}
-		}
-		return listeners, true
-	}
-
-	return nil, false
-}
-
-func (view *viewData) setKeyListener(tag string, value any) bool {
-	listeners, ok := valueToEventListeners[View, KeyEvent](value)
-	if !ok {
 	notCompatibleType(tag, value)
 	return false
 }
 
-	if listeners == nil {
+func (view *viewData) removeKeyListener(tag PropertyName) {
-		view.removeKeyListener(tag)
-	} else {
-		switch tag {
-		case KeyDownEvent:
-			view.properties[tag] = listeners
-			if view.created {
-				view.session.updateProperty(view.htmlID(), "onkeydown", "keyDownEvent(this, event)")
-			}
-
-		case KeyUpEvent:
-			view.properties[tag] = listeners
-			if view.created {
-				view.session.updateProperty(view.htmlID(), "onkeyup", "keyUpEvent(this, event)")
-			}
-
-		default:
-			return false
-		}
-	}
-
-	return true
-}
-
-func (view *viewData) removeKeyListener(tag string) {
 	delete(view.properties, tag)
 	if view.created {
 		switch tag {
@@ -778,34 +457,7 @@ func (view *viewData) removeKeyListener(tag string) {
 		}
 	}
 }
-
+*/
-func getEventWithOldListeners[V View, E any](view View, subviewID []string, tag string) []func(V, E, E) {
-	if len(subviewID) > 0 && subviewID[0] != "" {
-		view = ViewByID(view, subviewID[0])
-	}
-	if view != nil {
-		if value := view.Get(tag); value != nil {
-			if result, ok := value.([]func(V, E, E)); ok {
-				return result
-			}
-		}
-	}
-	return []func(V, E, E){}
-}
-
-func getEventListeners[V View, E any](view View, subviewID []string, tag string) []func(V, E) {
-	if len(subviewID) > 0 && subviewID[0] != "" {
-		view = ViewByID(view, subviewID[0])
-	}
-	if view != nil {
-		if value := view.Get(tag); value != nil {
-			if result, ok := value.([]func(V, E)); ok {
-				return result
-			}
-		}
-	}
-	return []func(V, E){}
-}
 
 func keyEventsHtml(view View, buffer *strings.Builder) {
 	if len(getEventListeners[View, KeyEvent](view, nil, KeyDownEvent)) > 0 {
@@ -821,7 +473,7 @@ func keyEventsHtml(view View, buffer *strings.Builder) {
 	}
 }
 
-func handleKeyEvents(view View, tag string, data DataObject) {
+func handleKeyEvents(view View, tag PropertyName, data DataObject) {
 	var event KeyEvent
 	event.init(data)
 	listeners := getEventListeners[View, KeyEvent](view, nil, tag)

listLayout.go

@@ -37,6 +37,7 @@ type ListLayout interface {
 	// UpdateContent updates child Views if the "content" property value is set to ListAdapter,
 	// otherwise does nothing
 	UpdateContent()
+	setAdapter(ListAdapter)
 }
 
 type listLayoutData struct {
@@ -53,7 +54,8 @@ func NewListLayout(session Session, params Params) ListLayout {
 }
 
 func newListLayout(session Session) View {
-	return NewListLayout(session, nil)
+	//return NewListLayout(session, nil)
+	return new(listLayoutData)
 }
 
 // Init initialize fields of ViewsAlignContainer by default values
@@ -61,14 +63,16 @@ func (listLayout *listLayoutData) init(session Session) {
 	listLayout.viewsContainerData.init(session)
 	listLayout.tag = "ListLayout"
 	listLayout.systemClass = "ruiListLayout"
+	listLayout.normalize = normalizeListLayoutTag
+	listLayout.getFunc = listLayout.get
+	listLayout.set = listLayout.setFunc
+	listLayout.remove = listLayout.removeFunc
+	listLayout.changed = listLayoutPropertyChanged
+
 }
 
-func (listLayout *listLayoutData) String() string {
+func normalizeListLayoutTag(tag PropertyName) PropertyName {
-	return getViewString(listLayout, nil)
+	tag = defaultNormalize(tag)
-}
-
-func (listLayout *listLayoutData) normalizeTag(tag string) string {
-	tag = strings.ToLower(tag)
 	switch tag {
 	case "wrap":
 		tag = ListWrap
@@ -82,80 +86,79 @@ func (listLayout *listLayoutData) normalizeTag(tag string) string {
 	return tag
 }
 
-func (listLayout *listLayoutData) Get(tag string) any {
+func (listLayout *listLayoutData) get(self View, tag PropertyName) any {
-	return listLayout.get(listLayout.normalizeTag(tag))
+	switch tag {
-}
+	case Gap:
-
-func (listLayout *listLayoutData) get(tag string) any {
-	if tag == Gap {
 		if rowGap := GetListRowGap(listLayout); rowGap.Equal(GetListColumnGap(listLayout)) {
 			return rowGap
 		}
 		return AutoSize()
-	}
-
-	return listLayout.viewsContainerData.get(tag)
-}
-
-func (listLayout *listLayoutData) Remove(tag string) {
-	listLayout.remove(listLayout.normalizeTag(tag))
-}
-
-func (listLayout *listLayoutData) remove(tag string) {
-	switch tag {
-	case Gap:
-		listLayout.remove(ListRowGap)
-		listLayout.remove(ListColumnGap)
-		return
 
 	case Content:
-		listLayout.adapter = nil
+		if listLayout.adapter != nil {
-	}
+			return listLayout.adapter
-
-	listLayout.viewsContainerData.remove(tag)
-	if listLayout.created {
-		switch tag {
-		case Orientation, ListWrap, HorizontalAlign, VerticalAlign:
-			updateCSSStyle(listLayout.htmlID(), listLayout.session)
-		}
 		}
 	}
 
-func (listLayout *listLayoutData) Set(tag string, value any) bool {
+	return listLayout.viewsContainerData.get(listLayout, tag)
-	return listLayout.set(listLayout.normalizeTag(tag), value)
-}
-
-func (listLayout *listLayoutData) set(tag string, value any) bool {
-	if value == nil {
-		listLayout.remove(tag)
-		return true
 }
 
+func (listLayout *listLayoutData) removeFunc(self View, tag PropertyName) []PropertyName {
 	switch tag {
 	case Gap:
-		return listLayout.set(ListRowGap, value) && listLayout.set(ListColumnGap, value)
+		result := []PropertyName{}
+		for _, tag := range []PropertyName{ListRowGap, ListColumnGap} {
+			if listLayout.getRaw(tag) != nil {
+				listLayout.setRaw(tag, nil)
+				result = append(result, tag)
+			}
+		}
+		return result
+
+	case Content:
+		listLayout.viewsContainerData.removeFunc(listLayout, Content)
+		listLayout.adapter = nil
+		return []PropertyName{Content}
+	}
+
+	return listLayout.viewsContainerData.removeFunc(listLayout, tag)
+}
+
+func (listLayout *listLayoutData) setFunc(self View, tag PropertyName, value any) []PropertyName {
+	switch tag {
+	case Gap:
+		result := listLayout.setFunc(listLayout, ListRowGap, value)
+		if result != nil {
+			if gap := listLayout.getRaw(ListRowGap); gap != nil {
+				listLayout.setRaw(ListColumnGap, gap)
+				result = append(result, ListColumnGap)
+			}
+		}
+		return result
 
 	case Content:
 		if adapter, ok := value.(ListAdapter); ok {
 			listLayout.adapter = adapter
-			listLayout.UpdateContent()
+			listLayout.createContent()
-			// TODO
+		} else if listLayout.setContent(value) {
-			return true
-		}
 			listLayout.adapter = nil
+		} else {
+			return nil
+		}
+		return []PropertyName{Content}
+	}
+	return listLayout.viewsContainerData.setFunc(listLayout, tag, value)
 }
 
-	if listLayout.viewsContainerData.set(tag, value) {
+func listLayoutPropertyChanged(view View, tag PropertyName) {
-		if listLayout.created {
 	switch tag {
 	case Orientation, ListWrap, HorizontalAlign, VerticalAlign:
-				updateCSSStyle(listLayout.htmlID(), listLayout.session)
+		updateCSSStyle(view.htmlID(), view.Session())
+
+	default:
+		viewsContainerPropertyChanged(view, tag)
 	}
 }
-		return true
-	}
-	return false
-}
 
 func (listLayout *listLayoutData) htmlSubviews(self View, buffer *strings.Builder) {
 	if listLayout.views != nil {
@@ -166,7 +169,14 @@ func (listLayout *listLayoutData) htmlSubviews(self View, buffer *strings.Builde
 	}
 }
 
-func (listLayout *listLayoutData) UpdateContent() {
+func (listLayout *listLayoutData) setAdapter(adapter ListAdapter) {
+	listLayout.adapter = adapter
+	if adapter != nil {
+		listLayout.createContent()
+	}
+}
+
+func (listLayout *listLayoutData) createContent() bool {
 	if adapter := listLayout.adapter; adapter != nil {
 		listLayout.views = []View{}
 
@@ -185,11 +195,20 @@ func (listLayout *listLayoutData) UpdateContent() {
 			}
 		}
 
-		if listLayout.created {
+		return true
-			updateInnerHTML(htmlID, session)
+	}
+	return false
 }
 
-		listLayout.propertyChangedEvent(Content)
+func (listLayout *listLayoutData) UpdateContent() {
+	if listLayout.createContent() {
+		if listLayout.created {
+			updateInnerHTML(listLayout.htmlID(), listLayout.session)
+		}
+
+		if listener, ok := listLayout.changeListener[Content]; ok {
+			listener(listLayout, Content)
+		}
 	}
 }
 

mediaPlayer.go

@@ -32,7 +32,7 @@ const (
 	// Values:
 	// `true` or `1` or "true", "yes", "on", "1" - The browser will offer controls to allow the user to control video playback, volume, seeking and pause/resume playback.
 	// `false` or `0` or "false", "no", "off", "0" - No controls will be visible to the end user.
-	Controls = "controls"
+	Controls PropertyName = "controls"
 
 	// Loop is the constant for "loop" property tag.
 	//
@@ -55,7 +55,7 @@ const (
 	// Values:
 	// `true` or `1` or "true", "yes", "on", "1" - The video player will automatically seek back to the start upon reaching the end of the video.
 	// `false` or `0` or "false", "no", "off", "0" - Video player will stop playing when the end of the media file has been reached.
-	Loop = "loop"
+	Loop PropertyName = "loop"
 
 	// Muted is the constant for "muted" property tag.
 	//
@@ -78,7 +78,7 @@ const (
 	// Values:
 	// `true` or `1` or "true", "yes", "on", "1" - Video will be muted.
 	// `false` or `0` or "false", "no", "off", "0" - Video playing normally.
-	Muted = "muted"
+	Muted PropertyName = "muted"
 
 	// Preload is the constant for "preload" property tag.
 	//
@@ -105,7 +105,7 @@ const (
 	// `0`(`PreloadNone`) or "none" - Media file must not be pre-loaded.
 	// `1`(`PreloadMetadata`) or "metadata" - Only metadata is preloaded.
 	// `2`(`PreloadAuto`) or "auto" - The entire media file can be downloaded even if the user doesn't have to use it.
-	Preload = "preload"
+	Preload PropertyName = "preload"
 
 	// AbortEvent is the constant for "abort-event" property tag.
 	//
@@ -134,7 +134,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	AbortEvent = "abort-event"
+	AbortEvent PropertyName = "abort-event"
 
 	// CanPlayEvent is the constant for "can-play-event" property tag.
 	//
@@ -165,7 +165,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	CanPlayEvent = "can-play-event"
+	CanPlayEvent PropertyName = "can-play-event"
 
 	// CanPlayThroughEvent is the constant for "can-play-through-event" property tag.
 	//
@@ -194,7 +194,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	CanPlayThroughEvent = "can-play-through-event"
+	CanPlayThroughEvent PropertyName = "can-play-through-event"
 
 	// CompleteEvent is the constant for "complete-event" property tag.
 	//
@@ -223,7 +223,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	CompleteEvent = "complete-event"
+	CompleteEvent PropertyName = "complete-event"
 
 	// DurationChangedEvent is the constant for "duration-changed-event" property tag.
 	//
@@ -258,7 +258,7 @@ const (
 	// `func(player rui.MediaPlayer)`,
 	// `func(duration float64)`,
 	// `func()`.
-	DurationChangedEvent = "duration-changed-event"
+	DurationChangedEvent PropertyName = "duration-changed-event"
 
 	// EmptiedEvent is the constant for "emptied-event" property tag.
 	//
@@ -289,7 +289,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	EmptiedEvent = "emptied-event"
+	EmptiedEvent PropertyName = "emptied-event"
 
 	// EndedEvent is the constant for "ended-event" property tag.
 	//
@@ -318,7 +318,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	EndedEvent = "ended-event"
+	EndedEvent PropertyName = "ended-event"
 
 	// LoadedDataEvent is the constant for "loaded-data-event" property tag.
 	//
@@ -347,7 +347,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	LoadedDataEvent = "loaded-data-event"
+	LoadedDataEvent PropertyName = "loaded-data-event"
 
 	// LoadedMetadataEvent is the constant for "loaded-metadata-event" property tag.
 	//
@@ -376,7 +376,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	LoadedMetadataEvent = "loaded-metadata-event"
+	LoadedMetadataEvent PropertyName = "loaded-metadata-event"
 
 	// LoadStartEvent is the constant for "load-start-event" property tag.
 	//
@@ -405,7 +405,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	LoadStartEvent = "load-start-event"
+	LoadStartEvent PropertyName = "load-start-event"
 
 	// PauseEvent is the constant for "pause-event" property tag.
 	//
@@ -434,7 +434,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	PauseEvent = "pause-event"
+	PauseEvent PropertyName = "pause-event"
 
 	// PlayEvent is the constant for "play-event" property tag.
 	//
@@ -463,7 +463,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	PlayEvent = "play-event"
+	PlayEvent PropertyName = "play-event"
 
 	// PlayingEvent is the constant for "playing-event" property tag.
 	//
@@ -492,7 +492,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	PlayingEvent = "playing-event"
+	PlayingEvent PropertyName = "playing-event"
 
 	// ProgressEvent is the constant for "progress-event" property tag.
 	//
@@ -521,7 +521,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	ProgressEvent = "progress-event"
+	ProgressEvent PropertyName = "progress-event"
 
 	// RateChangedEvent is the constant for "rate-changed-event" property tag.
 	//
@@ -556,7 +556,7 @@ const (
 	// `func(player rui.MediaPlayer)`,
 	// `func(rate float64)`,
 	// `func()`.
-	RateChangedEvent = "rate-changed-event"
+	RateChangedEvent PropertyName = "rate-changed-event"
 
 	// SeekedEvent is the constant for "seeked-event" property tag.
 	//
@@ -585,7 +585,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	SeekedEvent = "seeked-event"
+	SeekedEvent PropertyName = "seeked-event"
 
 	// SeekingEvent is the constant for "seeking-event" property tag.
 	//
@@ -614,7 +614,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	SeekingEvent = "seeking-event"
+	SeekingEvent PropertyName = "seeking-event"
 
 	// StalledEvent is the constant for "stalled-event" property tag.
 	//
@@ -643,7 +643,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	StalledEvent = "stalled-event"
+	StalledEvent PropertyName = "stalled-event"
 
 	// SuspendEvent is the constant for "suspend-event" property tag.
 	//
@@ -672,7 +672,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	SuspendEvent = "suspend-event"
+	SuspendEvent PropertyName = "suspend-event"
 
 	// TimeUpdateEvent is the constant for "time-update-event" property tag.
 	//
@@ -707,7 +707,7 @@ const (
 	// `func(player rui.MediaPlayer)`,
 	// `func(time float64)`,
 	// `func()`.
-	TimeUpdateEvent = "time-update-event"
+	TimeUpdateEvent PropertyName = "time-update-event"
 
 	// VolumeChangedEvent is the constant for "volume-changed-event" property tag.
 	//
@@ -742,7 +742,7 @@ const (
 	// `func(player rui.MediaPlayer)`,
 	// `func(volume float64)`,
 	// `func()`.
-	VolumeChangedEvent = "volume-changed-event"
+	VolumeChangedEvent PropertyName = "volume-changed-event"
 
 	// WaitingEvent is the constant for "waiting-event" property tag.
 	//
@@ -771,7 +771,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	WaitingEvent = "waiting-event"
+	WaitingEvent PropertyName = "waiting-event"
 
 	// PlayerErrorEvent is the constant for "player-error-event" property tag.
 	//
@@ -820,7 +820,7 @@ const (
 	// `func(code int, message string)`,
 	// `func(player rui.MediaPlayer)`,
 	// `func()`.
-	PlayerErrorEvent = "player-error-event"
+	PlayerErrorEvent PropertyName = "player-error-event"
 
 	// PreloadNone - value of the view "preload" property: indicates that the audio/video should not be preloaded.
 	PreloadNone = 0
@@ -907,119 +907,70 @@ type MediaSource struct {
 func (player *mediaPlayerData) init(session Session) {
 	player.viewData.init(session)
 	player.tag = "MediaPlayer"
-}
+	player.set = mediaPlayerSet
-
+	player.changed = mediaPlayerPropertyChanged
-func (player *mediaPlayerData) String() string {
-	return getViewString(player, nil)
 }
 
 func (player *mediaPlayerData) Focusable() bool {
 	return true
 }
 
-func (player *mediaPlayerData) Remove(tag string) {
+func mediaPlayerSet(view View, tag PropertyName, value any) []PropertyName {
-	player.remove(strings.ToLower(tag))
-}
-
-func (player *mediaPlayerData) remove(tag string) {
-	player.viewData.remove(tag)
-	player.propertyChanged(tag)
-}
-
-func (player *mediaPlayerData) Set(tag string, value any) bool {
-	return player.set(strings.ToLower(tag), value)
-}
-
-func (player *mediaPlayerData) set(tag string, value any) bool {
-	if value == nil {
-		player.remove(tag)
-		return true
-	}
-
 	switch tag {
-	case Controls, Loop, Muted, Preload:
-		if player.viewData.set(tag, value) {
-			player.propertyChanged(tag)
-			return true
-		}
 
 	case AbortEvent, CanPlayEvent, CanPlayThroughEvent, CompleteEvent, EmptiedEvent, LoadStartEvent,
 		EndedEvent, LoadedDataEvent, LoadedMetadataEvent, PauseEvent, PlayEvent, PlayingEvent,
 		ProgressEvent, SeekedEvent, SeekingEvent, StalledEvent, SuspendEvent, WaitingEvent:
-		if listeners, ok := valueToNoParamListeners[MediaPlayer](value); ok {
+
-			if listeners == nil {
+		return setNoParamEventListener[MediaPlayer](view, tag, value)
-				delete(player.properties, tag)
-			} else {
-				player.properties[tag] = listeners
-			}
-			player.propertyChanged(tag)
-			player.propertyChangedEvent(tag)
-			return true
-		}
-		notCompatibleType(tag, value)
 
 	case DurationChangedEvent, RateChangedEvent, TimeUpdateEvent, VolumeChangedEvent:
-		if listeners, ok := valueToEventListeners[MediaPlayer, float64](value); ok {
+
-			if listeners == nil {
+		return setViewEventListener[MediaPlayer, float64](view, tag, value)
-				delete(player.properties, tag)
-			} else {
-				player.properties[tag] = listeners
-			}
-			player.propertyChanged(tag)
-			player.propertyChangedEvent(tag)
-			return true
-		}
-		notCompatibleType(tag, value)
 
 	case PlayerErrorEvent:
 		if listeners, ok := valueToPlayerErrorListeners(value); ok {
-			if listeners == nil {
+			if len(listeners) > 0 {
-				delete(player.properties, tag)
+				view.setRaw(tag, listeners)
+			} else if view.getRaw(tag) != nil {
+				view.setRaw(tag, nil)
 			} else {
-				player.properties[tag] = listeners
+				return []PropertyName{}
 			}
-			player.propertyChanged(tag)
+			return []PropertyName{tag}
-			player.propertyChangedEvent(tag)
-			return true
 		}
 		notCompatibleType(tag, value)
+		return nil
 
 	case Source:
-		if player.setSource(value) {
+		return setMediaPlayerSource(view, value)
-			player.propertyChanged(tag)
-			player.propertyChangedEvent(tag)
-			return true
 	}
 
-	default:
+	return viewSet(view, tag, value)
-		return player.viewData.set(tag, value)
 }
 
-	return false
+func setMediaPlayerSource(properties Properties, value any) []PropertyName {
-}
-
-func (player *mediaPlayerData) setSource(value any) bool {
 	switch value := value.(type) {
 	case string:
 		src := MediaSource{Url: value, MimeType: ""}
-		player.properties[Source] = []MediaSource{src}
+		properties.setRaw(Source, []MediaSource{src})
 
 	case MediaSource:
-		player.properties[Source] = []MediaSource{value}
+		properties.setRaw(Source, []MediaSource{value})
 
 	case []MediaSource:
-		player.properties[Source] = value
+		properties.setRaw(Source, value)
 
 	case DataObject:
 		url, ok := value.PropertyValue("src")
 		if !ok || url == "" {
 			invalidPropertyValue(Source, value)
-			return false
+			return nil
 		}
 
 		mimeType, _ := value.PropertyValue("mime-type")
 		src := MediaSource{Url: url, MimeType: mimeType}
-		player.properties[Source] = []MediaSource{src}
+		properties.setRaw(Source, []MediaSource{src})
 
 	case []DataValue:
 		src := []MediaSource{}
@@ -1031,7 +982,7 @@ func (player *mediaPlayerData) setSource(value any) bool {
 					src = append(src, MediaSource{Url: url, MimeType: mimeType})
 				} else {
 					invalidPropertyValue(Source, value)
-					return false
+					return nil
 				}
 			} else {
 				src = append(src, MediaSource{Url: val.Value(), MimeType: ""})
@@ -1040,16 +991,16 @@ func (player *mediaPlayerData) setSource(value any) bool {
 
 		if len(src) == 0 {
 			invalidPropertyValue(Source, value)
-			return false
+			return nil
 		}
-		player.properties[Source] = src
+		properties.setRaw(Source, src)
 
 	default:
 		notCompatibleType(Source, value)
-		return false
+		return nil
 	}
 
-	return true
+	return []PropertyName{Source}
 }
 
 func valueToPlayerErrorListeners(value any) ([]func(MediaPlayer, int, string), bool) {
@@ -1177,109 +1128,106 @@ func valueToPlayerErrorListeners(value any) ([]func(MediaPlayer, int, string), b
 	return nil, false
 }
 
-func playerEvents() []struct{ tag, cssTag string } {
+func mediaPlayerEvents() map[PropertyName]string {
-	return []struct{ tag, cssTag string }{
+	return map[PropertyName]string{
-		{AbortEvent, "onabort"},
+		AbortEvent:          "onabort",
-		{CanPlayEvent, "oncanplay"},
+		CanPlayEvent:        "oncanplay",
-		{CanPlayThroughEvent, "oncanplaythrough"},
+		CanPlayThroughEvent: "oncanplaythrough",
-		{CompleteEvent, "oncomplete"},
+		CompleteEvent:       "oncomplete",
-		{EmptiedEvent, "onemptied"},
+		EmptiedEvent:        "onemptied",
-		{EndedEvent, "ended"},
+		EndedEvent:          "ended",
-		{LoadedDataEvent, "onloadeddata"},
+		LoadedDataEvent:     "onloadeddata",
-		{LoadedMetadataEvent, "onloadedmetadata"},
+		LoadedMetadataEvent: "onloadedmetadata",
-		{LoadStartEvent, "onloadstart"},
+		LoadStartEvent:      "onloadstart",
-		{PauseEvent, "onpause"},
+		PauseEvent:          "onpause",
-		{PlayEvent, "onplay"},
+		PlayEvent:           "onplay",
-		{PlayingEvent, "onplaying"},
+		PlayingEvent:        "onplaying",
-		{ProgressEvent, "onprogress"},
+		ProgressEvent:       "onprogress",
-		{SeekedEvent, "onseeked"},
+		SeekedEvent:         "onseeked",
-		{SeekingEvent, "onseeking"},
+		SeekingEvent:        "onseeking",
-		{StalledEvent, "onstalled"},
+		StalledEvent:        "onstalled",
-		{SuspendEvent, "onsuspend"},
+		SuspendEvent:        "onsuspend",
-		{WaitingEvent, "onwaiting"},
+		WaitingEvent:        "onwaiting",
 	}
 }
 
-func (player *mediaPlayerData) propertyChanged(tag string) {
+func mediaPlayerPropertyChanged(view View, tag PropertyName) {
-	if player.created {
+	session := view.Session()
+
 	switch tag {
 	case Controls, Loop:
-			value, _ := boolProperty(player, tag, player.session)
+		value, _ := boolProperty(view, tag, session)
 		if value {
-				player.session.updateProperty(player.htmlID(), tag, value)
+			session.updateProperty(view.htmlID(), string(tag), value)
 		} else {
-				player.session.removeProperty(player.htmlID(), tag)
+			session.removeProperty(view.htmlID(), string(tag))
 		}
 
 	case Muted:
-			value, _ := boolProperty(player, tag, player.session)
+		value, _ := boolProperty(view, Muted, session)
-			player.session.callFunc("setMediaMuted", player.htmlID(), value)
+		session.callFunc("setMediaMuted", view.htmlID(), value)
 
 	case Preload:
-			value, _ := enumProperty(player, tag, player.session, 0)
+		value, _ := enumProperty(view, Preload, session, 0)
 		values := enumProperties[Preload].values
-			player.session.updateProperty(player.htmlID(), tag, values[value])
+		session.updateProperty(view.htmlID(), string(Preload), values[value])
 
 	case AbortEvent, CanPlayEvent, CanPlayThroughEvent, CompleteEvent, EmptiedEvent,
 		EndedEvent, LoadedDataEvent, LoadedMetadataEvent, PauseEvent, PlayEvent, PlayingEvent, ProgressEvent,
 		LoadStartEvent, SeekedEvent, SeekingEvent, StalledEvent, SuspendEvent, WaitingEvent:
 
-			for _, event := range playerEvents() {
+		if cssTag, ok := mediaPlayerEvents()[tag]; ok {
-				if event.tag == tag {
+			fn := ""
-					if value := player.getRaw(event.tag); value != nil {
+			if value := view.getRaw(tag); value != nil {
-						switch value := value.(type) {
+				if listeners, ok := value.([]func(MediaPlayer)); ok && len(listeners) > 0 {
-						case []func(MediaPlayer):
+					fn = fmt.Sprintf(`viewEvent(this, "%s")`, string(tag))
-							if len(value) > 0 {
-								fn := fmt.Sprintf(`playerEvent(this, "%s")`, event.tag)
-								player.session.updateProperty(player.htmlID(), event.cssTag, fn)
-								return
 				}
 			}
-					}
+			session.updateProperty(view.htmlID(), cssTag, fn)
-					player.session.updateProperty(player.htmlID(), tag, "")
-					break
 		}
 
-			}
 	case TimeUpdateEvent:
-			if value := player.getRaw(tag); value != nil {
+		if value := view.getRaw(tag); value != nil {
-				player.session.updateProperty(player.htmlID(), "ontimeupdate", "playerTimeUpdatedEvent(this)")
+			session.updateProperty(view.htmlID(), "ontimeupdate", "viewTimeUpdatedEvent(this)")
 		} else {
-				player.session.updateProperty(player.htmlID(), "ontimeupdate", "")
+			session.updateProperty(view.htmlID(), "ontimeupdate", "")
 		}
 
 	case VolumeChangedEvent:
-			if value := player.getRaw(tag); value != nil {
+		if value := view.getRaw(tag); value != nil {
-				player.session.updateProperty(player.htmlID(), "onvolumechange", "playerVolumeChangedEvent(this)")
+			session.updateProperty(view.htmlID(), "onvolumechange", "viewVolumeChangedEvent(this)")
 		} else {
-				player.session.updateProperty(player.htmlID(), "onvolumechange", "")
+			session.updateProperty(view.htmlID(), "onvolumechange", "")
 		}
 
 	case DurationChangedEvent:
-			if value := player.getRaw(tag); value != nil {
+		if value := view.getRaw(tag); value != nil {
-				player.session.updateProperty(player.htmlID(), "ondurationchange", "playerDurationChangedEvent(this)")
+			session.updateProperty(view.htmlID(), "ondurationchange", "viewDurationChangedEvent(this)")
 		} else {
-				player.session.updateProperty(player.htmlID(), "ondurationchange", "")
+			session.updateProperty(view.htmlID(), "ondurationchange", "")
 		}
 
 	case RateChangedEvent:
-			if value := player.getRaw(tag); value != nil {
+		if value := view.getRaw(tag); value != nil {
-				player.session.updateProperty(player.htmlID(), "onratechange", "playerRateChangedEvent(this)")
+			session.updateProperty(view.htmlID(), "onratechange", "viewRateChangedEvent(this)")
 		} else {
-				player.session.updateProperty(player.htmlID(), "onratechange", "")
+			session.updateProperty(view.htmlID(), "onratechange", "")
 		}
 
 	case PlayerErrorEvent:
-			if value := player.getRaw(tag); value != nil {
+		if value := view.getRaw(tag); value != nil {
-				player.session.updateProperty(player.htmlID(), "onerror", "playerErrorEvent(this)")
+			session.updateProperty(view.htmlID(), "onerror", "viewErrorEvent(this)")
 		} else {
-				player.session.updateProperty(player.htmlID(), "onerror", "")
+			session.updateProperty(view.htmlID(), "onerror", "")
 		}
 
 	case Source:
-			updateInnerHTML(player.htmlID(), player.session)
+		updateInnerHTML(view.htmlID(), session)
-		}
+
+	default:
+		viewPropertyChanged(view, tag)
 	}
+
 }
 
 func (player *mediaPlayerData) htmlSubviews(self View, buffer *strings.Builder) {
@@ -1305,10 +1253,10 @@ func (player *mediaPlayerData) htmlSubviews(self View, buffer *strings.Builder)
 
 func (player *mediaPlayerData) htmlProperties(self View, buffer *strings.Builder) {
 	player.viewData.htmlProperties(self, buffer)
-	for _, tag := range []string{Controls, Loop, Muted, Preload} {
+	for _, tag := range []PropertyName{Controls, Loop, Muted, Preload} {
 		if value, _ := boolProperty(player, tag, player.session); value {
 			buffer.WriteRune(' ')
-			buffer.WriteString(tag)
+			buffer.WriteString(string(tag))
 		}
 	}
 
@@ -1319,20 +1267,17 @@ func (player *mediaPlayerData) htmlProperties(self View, buffer *strings.Builder
 		buffer.WriteRune('"')
 	}
 
-	for _, event := range playerEvents() {
+	for tag, cssTag := range mediaPlayerEvents() {
-		if value := player.getRaw(event.tag); value != nil {
+		if value := player.getRaw(tag); value != nil {
-			switch value := value.(type) {
+			if listeners, ok := value.([]func(MediaPlayer)); ok && len(listeners) > 0 {
-			case []func(MediaPlayer):
-				if len(value) > 0 {
 				buffer.WriteString(` `)
-					buffer.WriteString(event.cssTag)
+				buffer.WriteString(cssTag)
 				buffer.WriteString(`="playerEvent(this, '`)
-					buffer.WriteString(event.tag)
+				buffer.WriteString(string(tag))
 				buffer.WriteString(`')"`)
 			}
 		}
 	}
-	}
 
 	if value := player.getRaw(TimeUpdateEvent); value != nil {
 		buffer.WriteString(` ontimeupdate="playerTimeUpdatedEvent(this)"`)
@@ -1355,7 +1300,7 @@ func (player *mediaPlayerData) htmlProperties(self View, buffer *strings.Builder
 	}
 }
 
-func (player *mediaPlayerData) handleCommand(self View, command string, data DataObject) bool {
+func (player *mediaPlayerData) handleCommand(self View, command PropertyName, data DataObject) bool {
 	switch command {
 	case AbortEvent, CanPlayEvent, CanPlayThroughEvent, CompleteEvent, LoadStartEvent,
 		EmptiedEvent, EndedEvent, LoadedDataEvent, LoadedMetadataEvent, PauseEvent, PlayEvent,

mouseEvents.go

@@ -23,7 +23,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(event rui.MouseEvent)`,
 	// `func()`.
-	ClickEvent = "click-event"
+	ClickEvent PropertyName = "click-event"
 
 	// DoubleClickEvent is the constant for "double-click-event" property tag.
 	//
@@ -41,7 +41,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(event rui.MouseEvent)`,
 	// `func()`.
-	DoubleClickEvent = "double-click-event"
+	DoubleClickEvent PropertyName = "double-click-event"
 
 	// MouseDown is the constant for "mouse-down" property tag.
 	//
@@ -59,7 +59,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(event rui.MouseEvent)`,
 	// `func()`.
-	MouseDown = "mouse-down"
+	MouseDown PropertyName = "mouse-down"
 
 	// MouseUp is the constant for "mouse-up" property tag.
 	//
@@ -78,7 +78,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(event rui.MouseEvent)`,
 	// `func()`.
-	MouseUp = "mouse-up"
+	MouseUp PropertyName = "mouse-up"
 
 	// MouseMove is the constant for "mouse-move" property tag.
 	//
@@ -96,7 +96,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(event rui.MouseEvent)`,
 	// `func()`.
-	MouseMove = "mouse-move"
+	MouseMove PropertyName = "mouse-move"
 
 	// MouseOut is the constant for "mouse-out" property tag.
 	//
@@ -116,7 +116,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(event rui.MouseEvent)`,
 	// `func()`.
-	MouseOut = "mouse-out"
+	MouseOut PropertyName = "mouse-out"
 
 	// MouseOver is the constant for "mouse-over" property tag.
 	//
@@ -135,7 +135,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(event rui.MouseEvent)`,
 	// `func()`.
-	MouseOver = "mouse-over"
+	MouseOver PropertyName = "mouse-over"
 
 	// ContextMenuEvent is the constant for "context-menu-event" property tag.
 	//
@@ -153,7 +153,7 @@ const (
 	// `func(view rui.View)`,
 	// `func(event rui.MouseEvent)`,
 	// `func()`.
-	ContextMenuEvent = "context-menu-event"
+	ContextMenuEvent PropertyName = "context-menu-event"
 
 	// PrimaryMouseButton is a number of the main pressed button, usually the left button or the un-initialized state
 	PrimaryMouseButton = 0
@@ -228,49 +228,33 @@ type MouseEvent struct {
 	MetaKey bool
 }
 
-var mouseEvents = map[string]struct{ jsEvent, jsFunc string }{
+/*
-	ClickEvent:       {jsEvent: "onclick", jsFunc: "clickEvent"},
+func setMouseListener(properties Properties, tag PropertyName, value any) bool {
-	DoubleClickEvent: {jsEvent: "ondblclick", jsFunc: "doubleClickEvent"},
+	if listeners, ok := valueToEventListeners[View, MouseEvent](value); ok {
-	MouseDown:        {jsEvent: "onmousedown", jsFunc: "mouseDownEvent"},
+		if len(listeners) == 0 {
-	MouseUp:          {jsEvent: "onmouseup", jsFunc: "mouseUpEvent"},
+			properties.setRaw(tag, nil)
-	MouseMove:        {jsEvent: "onmousemove", jsFunc: "mouseMoveEvent"},
+		} else {
-	MouseOut:         {jsEvent: "onmouseout", jsFunc: "mouseOutEvent"},
+			properties.setRaw(tag, listeners)
-	MouseOver:        {jsEvent: "onmouseover", jsFunc: "mouseOverEvent"},
+		}
-	ContextMenuEvent: {jsEvent: "oncontextmenu", jsFunc: "contextMenuEvent"},
+		return true
 	}
-
-func (view *viewData) setMouseListener(tag string, value any) bool {
-	listeners, ok := valueToEventListeners[View, MouseEvent](value)
-	if !ok {
 	notCompatibleType(tag, value)
 	return false
 }
 
-	if listeners == nil {
+func (view *viewData) removeMouseListener(tag PropertyName) {
-		view.removeMouseListener(tag)
-	} else if js, ok := mouseEvents[tag]; ok {
-		view.properties[tag] = listeners
-		if view.created {
-			view.session.updateProperty(view.htmlID(), js.jsEvent, js.jsFunc+"(this, event)")
-		}
-	} else {
-		return false
-	}
-	return true
-}
-
-func (view *viewData) removeMouseListener(tag string) {
 	delete(view.properties, tag)
 	if view.created {
-		if js, ok := mouseEvents[tag]; ok {
+		if js, ok := eventJsFunc[tag]; ok {
 			view.session.removeProperty(view.htmlID(), js.jsEvent)
 		}
 	}
 }
 
 func mouseEventsHtml(view View, buffer *strings.Builder, hasTooltip bool) {
-	for tag, js := range mouseEvents {
+	for _, tag := range []PropertyName{ClickEvent, DoubleClickEvent, MouseDown, MouseUp, MouseMove, MouseOut, MouseOver, ContextMenuEvent} {
 		if value := view.getRaw(tag); value != nil {
+			if js, ok := eventJsFunc[tag]; ok {
 				if listeners, ok := value.([]func(View, MouseEvent)); ok && len(listeners) > 0 {
 					buffer.WriteString(js.jsEvent)
 					buffer.WriteString(`="`)
@@ -279,12 +263,14 @@ func mouseEventsHtml(view View, buffer *strings.Builder, hasTooltip bool) {
 				}
 			}
 		}
+	}
 
 	if hasTooltip {
 		buffer.WriteString(`onmouseenter="mouseEnterEvent(this, event)" `)
 		buffer.WriteString(`onmouseleave="mouseLeaveEvent(this, event)" `)
 	}
 }
+*/
 
 func getTimeStamp(data DataObject) uint64 {
 	if value, ok := data.PropertyValue("timeStamp"); ok {
@@ -315,7 +301,7 @@ func (event *MouseEvent) init(data DataObject) {
 	event.MetaKey = dataBoolProperty(data, "metaKey")
 }
 
-func handleMouseEvents(view View, tag string, data DataObject) {
+func handleMouseEvents(view View, tag PropertyName, data DataObject) {
 	listeners := getEventListeners[View, MouseEvent](view, nil, tag)
 	if len(listeners) > 0 {
 		var event MouseEvent

numberPicker.go

@@ -26,7 +26,7 @@ const (
 	// `func(newValue, oldValue float64)`,
 	// `func(newValue float64)`,
 	// `func()`.
-	NumberChangedEvent = "number-changed"
+	NumberChangedEvent PropertyName = "number-changed"
 
 	// NumberPickerType is the constant for "number-picker-type" property tag.
 	//
@@ -38,7 +38,7 @@ const (
 	// Values:
 	// `0`(`NumberEditor`) or "editor" - Displayed as an editor.
 	// `1`(`NumberSlider`) or "slider" - Displayed as a slider.
-	NumberPickerType = "number-picker-type"
+	NumberPickerType PropertyName = "number-picker-type"
 
 	// NumberPickerMin is the constant for "number-picker-min" property tag.
 	//
@@ -48,7 +48,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	NumberPickerMin = "number-picker-min"
+	NumberPickerMin PropertyName = "number-picker-min"
 
 	// NumberPickerMax is the constant for "number-picker-max" property tag.
 	//
@@ -58,7 +58,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	NumberPickerMax = "number-picker-max"
+	NumberPickerMax PropertyName = "number-picker-max"
 
 	// NumberPickerStep is the constant for "number-picker-step" property tag.
 	//
@@ -68,7 +68,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	NumberPickerStep = "number-picker-step"
+	NumberPickerStep PropertyName = "number-picker-step"
 
 	// NumberPickerValue is the constant for "number-picker-value" property tag.
 	//
@@ -78,7 +78,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	NumberPickerValue = "number-picker-value"
+	NumberPickerValue PropertyName = "number-picker-value"
 )
 
 // Constants which describe values of the "number-picker-type" property of a [NumberPicker]
@@ -97,8 +97,6 @@ type NumberPicker interface {
 
 type numberPickerData struct {
 	viewData
-	dataList
-	numberChangedListeners []func(NumberPicker, float64, float64)
 }
 
 // NewNumberPicker create new NumberPicker object and return it
@@ -110,165 +108,92 @@ func NewNumberPicker(session Session, params Params) NumberPicker {
 }
 
 func newNumberPicker(session Session) View {
-	return NewNumberPicker(session, nil)
+	return new(numberPickerData)
 }
 
 func (picker *numberPickerData) init(session Session) {
 	picker.viewData.init(session)
 	picker.tag = "NumberPicker"
 	picker.hasHtmlDisabled = true
-	picker.numberChangedListeners = []func(NumberPicker, float64, float64){}
+	picker.normalize = normalizeNumberPickerTag
-	picker.dataListInit()
+	picker.set = numberPickerSet
-}
+	picker.changed = numberPickerPropertyChanged
-
-func (picker *numberPickerData) String() string {
-	return getViewString(picker, nil)
 }
 
 func (picker *numberPickerData) Focusable() bool {
 	return true
 }
 
-func (picker *numberPickerData) normalizeTag(tag string) string {
+func normalizeNumberPickerTag(tag PropertyName) PropertyName {
-	tag = strings.ToLower(tag)
+	tag = defaultNormalize(tag)
 	switch tag {
 	case Type, Min, Max, Step, Value:
 		return "number-picker-" + tag
 	}
 
-	return picker.normalizeDataListTag(tag)
+	return normalizeDataListTag(tag)
 }
 
-func (picker *numberPickerData) Remove(tag string) {
+func numberPickerSet(view View, tag PropertyName, value any) []PropertyName {
-	picker.remove(picker.normalizeTag(tag))
-}
-
-func (picker *numberPickerData) remove(tag string) {
 	switch tag {
 	case NumberChangedEvent:
-		if len(picker.numberChangedListeners) > 0 {
+		return setEventWithOldListener[NumberPicker, float64](view, tag, value)
-			picker.numberChangedListeners = []func(NumberPicker, float64, float64){}
-			picker.propertyChangedEvent(tag)
-		}
 
 	case NumberPickerValue:
-		oldValue := GetNumberPickerValue(picker)
+		view.setRaw("old-number", GetNumberPickerValue(view))
-		picker.viewData.remove(tag)
+		min, max := GetNumberPickerMinMax(view)
-		if oldValue != 0 {
+
-			if picker.created {
+		return setFloatProperty(view, NumberPickerValue, value, min, max)
-				picker.session.callFunc("setInputValue", picker.htmlID(), 0)
-			}
-			for _, listener := range picker.numberChangedListeners {
-				listener(picker, 0, oldValue)
-			}
-			picker.propertyChangedEvent(tag)
-		}
 
 	case DataList:
-		if len(picker.dataList.dataList) > 0 {
+		return setDataList(view, value, "")
-			picker.setDataList(picker, []string{}, true)
 	}
 
-	default:
+	return viewSet(view, tag, value)
-		picker.viewData.remove(tag)
-		picker.propertyChanged(tag)
-	}
 }
 
-func (picker *numberPickerData) Set(tag string, value any) bool {
+func numberPickerPropertyChanged(view View, tag PropertyName) {
-	return picker.set(picker.normalizeTag(tag), value)
-}
-
-func (picker *numberPickerData) set(tag string, value any) bool {
-	if value == nil {
-		picker.remove(tag)
-		return true
-	}
-
-	switch tag {
-	case NumberChangedEvent:
-		listeners, ok := valueToEventWithOldListeners[NumberPicker, float64](value)
-		if !ok {
-			notCompatibleType(tag, value)
-			return false
-		} else if listeners == nil {
-			listeners = []func(NumberPicker, float64, float64){}
-		}
-		picker.numberChangedListeners = listeners
-		picker.propertyChangedEvent(tag)
-		return true
-
-	case NumberPickerValue:
-		oldValue := GetNumberPickerValue(picker)
-		min, max := GetNumberPickerMinMax(picker)
-		if picker.setFloatProperty(NumberPickerValue, value, min, max) {
-			if f, ok := floatProperty(picker, NumberPickerValue, picker.Session(), min); ok && f != oldValue {
-				newValue, _ := floatTextProperty(picker, NumberPickerValue, picker.Session(), min)
-				if picker.created {
-					picker.session.callFunc("setInputValue", picker.htmlID(), newValue)
-				}
-				for _, listener := range picker.numberChangedListeners {
-					listener(picker, f, oldValue)
-				}
-				picker.propertyChangedEvent(tag)
-			}
-			return true
-		}
-
-	case DataList:
-		return picker.setDataList(picker, value, picker.created)
-
-	default:
-		if picker.viewData.set(tag, value) {
-			picker.propertyChanged(tag)
-			return true
-		}
-	}
-	return false
-}
-
-func (picker *numberPickerData) propertyChanged(tag string) {
-	if picker.created {
 	switch tag {
 	case NumberPickerType:
-			if GetNumberPickerType(picker) == NumberSlider {
+		if GetNumberPickerType(view) == NumberSlider {
-				picker.session.updateProperty(picker.htmlID(), "type", "range")
+			view.Session().updateProperty(view.htmlID(), "type", "range")
 		} else {
-				picker.session.updateProperty(picker.htmlID(), "type", "number")
+			view.Session().updateProperty(view.htmlID(), "type", "number")
 		}
 
 	case NumberPickerMin:
-			min, _ := GetNumberPickerMinMax(picker)
+		min, _ := GetNumberPickerMinMax(view)
-			picker.session.updateProperty(picker.htmlID(), Min, strconv.FormatFloat(min, 'f', -1, 32))
+		view.Session().updateProperty(view.htmlID(), "min", strconv.FormatFloat(min, 'f', -1, 32))
 
 	case NumberPickerMax:
-			_, max := GetNumberPickerMinMax(picker)
+		_, max := GetNumberPickerMinMax(view)
-			picker.session.updateProperty(picker.htmlID(), Max, strconv.FormatFloat(max, 'f', -1, 32))
+		view.Session().updateProperty(view.htmlID(), "max", strconv.FormatFloat(max, 'f', -1, 32))
 
 	case NumberPickerStep:
-			if step := GetNumberPickerStep(picker); step > 0 {
+		if step := GetNumberPickerStep(view); step > 0 {
-				picker.session.updateProperty(picker.htmlID(), Step, strconv.FormatFloat(step, 'f', -1, 32))
+			view.Session().updateProperty(view.htmlID(), "step", strconv.FormatFloat(step, 'f', -1, 32))
 		} else {
-				picker.session.updateProperty(picker.htmlID(), Step, "any")
+			view.Session().updateProperty(view.htmlID(), "step", "any")
-			}
-		}
-	}
 		}
 
-func (picker *numberPickerData) Get(tag string) any {
+	case TimePickerValue:
-	return picker.get(picker.normalizeTag(tag))
+		value := GetNumberPickerValue(view)
+		view.Session().callFunc("setInputValue", view.htmlID(), value)
+
+		if listeners := GetNumberChangedListeners(view); len(listeners) > 0 {
+			old := 0.0
+			if val := view.getRaw("old-number"); val != nil {
+				if n, ok := val.(float64); ok {
+					old = n
+				}
+			}
+			for _, listener := range listeners {
+				listener(view, value, old)
+			}
 		}
-
-func (picker *numberPickerData) get(tag string) any {
-	switch tag {
-	case NumberChangedEvent:
-		return picker.numberChangedListeners
-
-	case DataList:
-		return picker.dataList.dataList
 
 	default:
-		return picker.viewData.get(tag)
+		viewPropertyChanged(view, tag)
 	}
 }
 
@@ -277,7 +202,10 @@ func (picker *numberPickerData) htmlTag() string {
 }
 
 func (picker *numberPickerData) htmlSubviews(self View, buffer *strings.Builder) {
-	picker.dataListHtmlSubviews(self, buffer)
+	dataListHtmlSubviews(self, buffer, func(text string, session Session) string {
+		text, _ = session.resolveConstants(text)
+		return text
+	})
 }
 
 func (picker *numberPickerData) htmlProperties(self View, buffer *strings.Builder) {
@@ -317,10 +245,10 @@ func (picker *numberPickerData) htmlProperties(self View, buffer *strings.Builde
 
 	buffer.WriteString(` oninput="editViewInputEvent(this)"`)
 
-	picker.dataListHtmlProperties(picker, buffer)
+	dataListHtmlProperties(picker, buffer)
 }
 
-func (picker *numberPickerData) handleCommand(self View, command string, data DataObject) bool {
+func (picker *numberPickerData) handleCommand(self View, command PropertyName, data DataObject) bool {
 	switch command {
 	case "textChanged":
 		if text, ok := data.PropertyValue("text"); ok {
@@ -328,9 +256,12 @@ func (picker *numberPickerData) handleCommand(self View, command string, data Da
 				oldValue := GetNumberPickerValue(picker)
 				picker.properties[NumberPickerValue] = text
 				if value != oldValue {
-					for _, listener := range picker.numberChangedListeners {
+					for _, listener := range GetNumberChangedListeners(picker) {
 						listener(picker, value, oldValue)
 					}
+					if listener, ok := picker.changeListener[NumberPickerValue]; ok {
+						listener(picker, NumberPickerValue)
+					}
 				}
 			}
 		}

outline.go

@@ -16,7 +16,7 @@ type OutlineProperty interface {
 }
 
 type outlinePropertyData struct {
-	propertyList
+	dataProperty
 }
 
 // NewOutlineProperty creates the new OutlineProperty.
@@ -27,22 +27,29 @@ type outlinePropertyData struct {
 // "width" (Width). Determines the line thickness (SizeUnit).
 func NewOutlineProperty(params Params) OutlineProperty {
 	outline := new(outlinePropertyData)
-	outline.properties = map[string]any{}
+	outline.init()
 	for tag, value := range params {
 		outline.Set(tag, value)
 	}
 	return outline
 }
 
+func (outline *outlinePropertyData) init() {
+	outline.propertyList.init()
+	outline.normalize = normalizeOutlineTag
+	outline.set = outlineSet
+	outline.supportedProperties = []PropertyName{Style, Width, ColorTag}
+}
+
 func (outline *outlinePropertyData) writeString(buffer *strings.Builder, indent string) {
 	buffer.WriteString("_{ ")
 	comma := false
-	for _, tag := range []string{Style, Width, ColorTag} {
+	for _, tag := range []PropertyName{Style, Width, ColorTag} {
 		if value, ok := outline.properties[tag]; ok {
 			if comma {
 				buffer.WriteString(", ")
 			}
-			buffer.WriteString(tag)
+			buffer.WriteString(string(tag))
 			buffer.WriteString(" = ")
 			writePropertyValue(buffer, BorderStyle, value, indent)
 			comma = true
@@ -56,46 +63,33 @@ func (outline *outlinePropertyData) String() string {
 	return runStringWriter(outline)
 }
 
-func (outline *outlinePropertyData) normalizeTag(tag string) string {
+func normalizeOutlineTag(tag PropertyName) PropertyName {
-	return strings.TrimPrefix(strings.ToLower(tag), "outline-")
+	tag = defaultNormalize(tag)
+	return PropertyName(strings.TrimPrefix(string(tag), "outline-"))
 }
 
-func (outline *outlinePropertyData) Remove(tag string) {
+func outlineSet(properties Properties, tag PropertyName, value any) []PropertyName {
-	delete(outline.properties, outline.normalizeTag(tag))
-}
-
-func (outline *outlinePropertyData) Set(tag string, value any) bool {
-	if value == nil {
-		outline.Remove(tag)
-		return true
-	}
-
-	tag = outline.normalizeTag(tag)
 	switch tag {
 	case Style:
-		return outline.setEnumProperty(Style, value, enumProperties[BorderStyle].values)
+		return setEnumProperty(properties, Style, value, enumProperties[BorderStyle].values)
 
 	case Width:
 		if width, ok := value.(SizeUnit); ok {
 			switch width.Type {
 			case SizeInFraction, SizeInPercent:
 				notCompatibleType(tag, value)
-				return false
+				return nil
 			}
 		}
-		return outline.setSizeProperty(Width, value)
+		return setSizeProperty(properties, Width, value)
 
 	case ColorTag:
-		return outline.setColorProperty(ColorTag, value)
+		return setColorProperty(properties, ColorTag, value)
 
 	default:
 		ErrorLogF(`"%s" property is not compatible with the OutlineProperty`, tag)
 	}
-	return false
+	return nil
-}
-
-func (outline *outlinePropertyData) Get(tag string) any {
-	return outline.propertyList.Get(outline.normalizeTag(tag))
 }
 
 func (outline *outlinePropertyData) ViewOutline(session Session) ViewOutline {
@@ -132,7 +126,7 @@ func (outline ViewOutline) cssString(session Session) string {
 	return builder.finish()
 }
 
-func getOutline(properties Properties) OutlineProperty {
+func getOutlineProperty(properties Properties) OutlineProperty {
 	if value := properties.Get(Outline); value != nil {
 		if outline, ok := value.(OutlineProperty); ok {
 			return outline
@@ -142,30 +136,30 @@ func getOutline(properties Properties) OutlineProperty {
 	return nil
 }
 
-func (style *viewStyle) setOutline(value any) bool {
+func setOutlineProperty(properties Properties, value any) []PropertyName {
 	switch value := value.(type) {
 	case OutlineProperty:
-		style.properties[Outline] = value
+		properties.setRaw(Outline, value)
 
 	case ViewOutline:
-		style.properties[Outline] = NewOutlineProperty(Params{Style: value.Style, Width: value.Width, ColorTag: value.Color})
+		properties.setRaw(Outline, NewOutlineProperty(Params{Style: value.Style, Width: value.Width, ColorTag: value.Color}))
 
 	case ViewBorder:
-		style.properties[Outline] = NewOutlineProperty(Params{Style: value.Style, Width: value.Width, ColorTag: value.Color})
+		properties.setRaw(Outline, NewOutlineProperty(Params{Style: value.Style, Width: value.Width, ColorTag: value.Color}))
 
 	case DataObject:
 		outline := NewOutlineProperty(nil)
-		for _, tag := range []string{Style, Width, ColorTag} {
+		for _, tag := range []PropertyName{Style, Width, ColorTag} {
-			if text, ok := value.PropertyValue(tag); ok && text != "" {
+			if text, ok := value.PropertyValue(string(tag)); ok && text != "" {
 				outline.Set(tag, text)
 			}
 		}
-		style.properties[Outline] = outline
+		properties.setRaw(Outline, outline)
 
 	default:
 		notCompatibleType(Outline, value)
-		return false
+		return nil
 	}
 
-	return true
+	return []PropertyName{Outline}
 }

params.go

@@ -3,15 +3,15 @@ package rui
 import "sort"
 
 // Params defines a type of a parameters list
-type Params map[string]any
+type Params map[PropertyName]any
 
 // Get returns a value of the property with name defined by the argument. The type of return value depends
 // on the property. If the property is not set then nil is returned.
-func (params Params) Get(tag string) any {
+func (params Params) Get(tag PropertyName) any {
 	return params.getRaw(tag)
 }
 
-func (params Params) getRaw(tag string) any {
+func (params Params) getRaw(tag PropertyName) any {
 	if value, ok := params[tag]; ok {
 		return value
 	}
@@ -20,12 +20,12 @@ func (params Params) getRaw(tag string) any {
 
 // Set sets the value (second argument) of the property with name defined by the first argument.
 // Return "true" if the value has been set, in the opposite case "false" is returned and a description of an error is written to the log
-func (params Params) Set(tag string, value any) bool {
+func (params Params) Set(tag PropertyName, value any) bool {
 	params.setRaw(tag, value)
 	return true
 }
 
-func (params Params) setRaw(tag string, value any) {
+func (params Params) setRaw(tag PropertyName, value any) {
 	if value != nil {
 		params[tag] = value
 	} else {
@@ -34,7 +34,7 @@ func (params Params) setRaw(tag string, value any) {
 }
 
 // Remove removes the property with name defined by the argument from a map.
-func (params Params) Remove(tag string) {
+func (params Params) Remove(tag PropertyName) {
 	delete(params, tag)
 }
 
@@ -46,11 +46,17 @@ func (params Params) Clear() {
 }
 
 // AllTags returns a sorted slice of all properties.
-func (params Params) AllTags() []string {
+func (params Params) AllTags() []PropertyName {
-	tags := make([]string, 0, len(params))
+	tags := make([]PropertyName, 0, len(params))
 	for t := range params {
 		tags = append(tags, t)
 	}
-	sort.Strings(tags)
+	sort.Slice(tags, func(i, j int) bool {
+		return tags[i] < tags[j]
+	})
 	return tags
 }
+
+func (params Params) empty() bool {
+	return len(params) == 0
+}

path.go

@@ -55,7 +55,6 @@ type Path interface {
 	// If the shape has already been closed or has only one point, this function does nothing.
 	Close()
 
-	//create(session Session)
 	obj() any
 }
 

pointerEvents.go

@@ -1,9 +1,5 @@
 package rui
 
-import (
-	"strings"
-)
-
 // Constants for [View] specific pointer events properties
 const (
 	// PointerDown is the constant for "pointer-down" property tag.
@@ -24,7 +20,7 @@ const (
 	// `func(event rui.PointerEvent)`,
 	// `func(view rui.View)`,
 	// `func()`.
-	PointerDown = "pointer-down"
+	PointerDown PropertyName = "pointer-down"
 
 	// PointerUp is the constant for "pointer-up" property tag.
 	//
@@ -42,7 +38,7 @@ const (
 	// `func(event rui.PointerEvent)`,
 	// `func(view rui.View)`,
 	// `func()`.
-	PointerUp = "pointer-up"
+	PointerUp PropertyName = "pointer-up"
 
 	// PointerMove is the constant for "pointer-move" property tag.
 	//
@@ -60,7 +56,7 @@ const (
 	// `func(event rui.PointerEvent)`,
 	// `func(view rui.View)`,
 	// `func()`.
-	PointerMove = "pointer-move"
+	PointerMove PropertyName = "pointer-move"
 
 	// PointerCancel is the constant for "pointer-cancel" property tag.
 	//
@@ -78,7 +74,7 @@ const (
 	// `func(event rui.PointerEvent)`,
 	// `func(view rui.View)`,
 	// `func()`.
-	PointerCancel = "pointer-cancel"
+	PointerCancel PropertyName = "pointer-cancel"
 
 	// PointerOut is the constant for "pointer-out" property tag.
 	//
@@ -98,7 +94,7 @@ const (
 	// `func(event rui.PointerEvent)`,
 	// `func(view rui.View)`,
 	// `func()`.
-	PointerOut = "pointer-out"
+	PointerOut PropertyName = "pointer-out"
 
 	// PointerOver is the constant for "pointer-over" property tag.
 	//
@@ -116,7 +112,7 @@ const (
 	// `func(event rui.PointerEvent)`,
 	// `func(view rui.View)`,
 	// `func()`.
-	PointerOver = "pointer-over"
+	PointerOver PropertyName = "pointer-over"
 )
 
 // PointerEvent represent a stylus events. Also inherit [MouseEvent] attributes
@@ -158,47 +154,33 @@ type PointerEvent struct {
 	IsPrimary bool
 }
 
-var pointerEvents = map[string]struct{ jsEvent, jsFunc string }{
+/*
-	PointerDown:   {jsEvent: "onpointerdown", jsFunc: "pointerDownEvent"},
+func setPointerListener(properties Properties, tag PropertyName, value any) bool {
-	PointerUp:     {jsEvent: "onpointerup", jsFunc: "pointerUpEvent"},
+	if listeners, ok := valueToEventListeners[View, PointerEvent](value); ok {
-	PointerMove:   {jsEvent: "onpointermove", jsFunc: "pointerMoveEvent"},
+		if len(listeners) == 0 {
-	PointerCancel: {jsEvent: "onpointercancel", jsFunc: "pointerCancelEvent"},
+			properties.setRaw(tag, nil)
-	PointerOut:    {jsEvent: "onpointerout", jsFunc: "pointerOutEvent"},
+		} else {
-	PointerOver:   {jsEvent: "onpointerover", jsFunc: "pointerOverEvent"},
+			properties.setRaw(tag, listeners)
+		}
+		return true
 	}
-
-func (view *viewData) setPointerListener(tag string, value any) bool {
-	listeners, ok := valueToEventListeners[View, PointerEvent](value)
-	if !ok {
 	notCompatibleType(tag, value)
 	return false
 }
 
-	if listeners == nil {
+func (view *viewData) removePointerListener(tag PropertyName) {
-		view.removePointerListener(tag)
-	} else if js, ok := pointerEvents[tag]; ok {
-		view.properties[tag] = listeners
-		if view.created {
-			view.session.updateProperty(view.htmlID(), js.jsEvent, js.jsFunc+"(this, event)")
-		}
-	} else {
-		return false
-	}
-	return true
-}
-
-func (view *viewData) removePointerListener(tag string) {
 	delete(view.properties, tag)
 	if view.created {
-		if js, ok := pointerEvents[tag]; ok {
+		if js, ok := eventJsFunc[tag]; ok {
 			view.session.removeProperty(view.htmlID(), js.jsEvent)
 		}
 	}
 }
 
 func pointerEventsHtml(view View, buffer *strings.Builder) {
-	for tag, js := range pointerEvents {
+	for _, tag := range []PropertyName{PointerDown, PointerUp, PointerMove, PointerOut, PointerOver, PointerCancel} {
 		if value := view.getRaw(tag); value != nil {
+			if js, ok := eventJsFunc[tag]; ok {
 				if listeners, ok := value.([]func(View, PointerEvent)); ok && len(listeners) > 0 {
 					buffer.WriteString(js.jsEvent)
 					buffer.WriteString(`="`)
@@ -208,6 +190,8 @@ func pointerEventsHtml(view View, buffer *strings.Builder) {
 			}
 		}
 	}
+}
+*/
 
 func (event *PointerEvent) init(data DataObject) {
 	event.MouseEvent.init(data)
@@ -225,7 +209,7 @@ func (event *PointerEvent) init(data DataObject) {
 	event.IsPrimary = dataBoolProperty(data, "isPrimary")
 }
 
-func handlePointerEvents(view View, tag string, data DataObject) {
+func handlePointerEvents(view View, tag PropertyName, data DataObject) {
 	listeners := getEventListeners[View, PointerEvent](view, nil, tag)
 	if len(listeners) == 0 {
 		return

popup.go

@@ -27,7 +27,7 @@ const (
 	// Set popup title style. Default title style is "ruiPopupTitle".
 	//
 	// Supported types: `string`.
-	TitleStyle = "title-style"
+	TitleStyle PropertyName = "title-style"
 
 	// CloseButton is the constant for "close-button" property tag.
 	//
@@ -39,7 +39,7 @@ const (
 	// Values:
 	// `true` or `1` or "true", "yes", "on", "1" - Close button will be added to a title bar of a window.
 	// `false` or `0` or "false", "no", "off", "0" - Popup without a close button.
-	CloseButton = "close-button"
+	CloseButton PropertyName = "close-button"
 
 	// OutsideClose is the constant for "outside-close" property tag.
 	//
@@ -51,7 +51,7 @@ const (
 	// Values:
 	// `true` or `1` or "true", "yes", "on", "1" - Clicking outside the popup window will automatically call the `Dismiss()` method.
 	// `false` or `0` or "false", "no", "off", "0" - Clicking outside the popup window has no effect.
-	OutsideClose = "outside-close"
+	OutsideClose PropertyName = "outside-close"
 
 	// Buttons is the constant for "buttons" property tag.
 	//
@@ -62,7 +62,7 @@ const (
 	//
 	// Internal type is `[]PopupButton`, other types converted to it during assignment.
 	// See `PopupButton` description for more details.
-	Buttons = "buttons"
+	Buttons PropertyName = "buttons"
 
 	// ButtonsAlign is the constant for "buttons-align" property tag.
 	//
@@ -76,7 +76,7 @@ const (
 	// `1`(`RightAlign`) or "right" - Right alignment.
 	// `2`(`CenterAlign`) or "center" - Center alignment.
 	// `3`(`StretchAlign`) or "stretch" - Width alignment.
-	ButtonsAlign = "buttons-align"
+	ButtonsAlign PropertyName = "buttons-align"
 
 	// DismissEvent is the constant for "dismiss-event" property tag.
 	//
@@ -91,7 +91,7 @@ const (
 	//
 	// Allowed listener formats:
 	// `func()`.
-	DismissEvent = "dismiss-event"
+	DismissEvent PropertyName = "dismiss-event"
 
 	// Arrow is the constant for "arrow" property tag.
 	//
@@ -106,7 +106,7 @@ const (
 	// `2`(`RightArrow`) or "right" - Arrow on the right side of the pop-up window.
 	// `3`(`BottomArrow`) or "bottom" - Arrow at the bottom of the pop-up window.
 	// `4`(`LeftArrow`) or "left" - Arrow on the left side of the pop-up window.
-	Arrow = "arrow"
+	Arrow PropertyName = "arrow"
 
 	// ArrowAlign is the constant for "arrow-align" property tag.
 	//
@@ -119,7 +119,7 @@ const (
 	// `0`(`TopAlign`/`LeftAlign`) or "top" - Top/left alignment.
 	// `1`(`BottomAlign`/`RightAlign`) or "bottom" - Bottom/right alignment.
 	// `2`(`CenterAlign`) or "center" - Center alignment.
-	ArrowAlign = "arrow-align"
+	ArrowAlign PropertyName = "arrow-align"
 
 	// ArrowSize is the constant for "arrow-size" property tag.
 	//
@@ -130,7 +130,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	ArrowSize = "arrow-size"
+	ArrowSize PropertyName = "arrow-size"
 
 	// ArrowWidth is the constant for "arrow-width" property tag.
 	//
@@ -141,7 +141,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	ArrowWidth = "arrow-width"
+	ArrowWidth PropertyName = "arrow-width"
 
 	// ArrowOffset is the constant for "arrow-offset" property tag.
 	//
@@ -152,7 +152,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	ArrowOffset = "arrow-offset"
+	ArrowOffset PropertyName = "arrow-offset"
 
 	// NoneArrow is value of the popup "arrow" property: no arrow
 	NoneArrow = 0

progressBar.go

@@ -15,7 +15,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	ProgressBarMax = "progress-max"
+	ProgressBarMax PropertyName = "progress-max"
 
 	// ProgressBarValue is the constant for "progress-value" property tag.
 	//
@@ -25,7 +25,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	ProgressBarValue = "progress-value"
+	ProgressBarValue PropertyName = "progress-value"
 )
 
 // ProgressBar represents a ProgressBar view
@@ -46,20 +46,18 @@ func NewProgressBar(session Session, params Params) ProgressBar {
 }
 
 func newProgressBar(session Session) View {
-	return NewProgressBar(session, nil)
+	return new(progressBarData)
 }
 
 func (progress *progressBarData) init(session Session) {
 	progress.viewData.init(session)
 	progress.tag = "ProgressBar"
+	progress.normalize = normalizeProgressBarTag
+	progress.changed = progressBarPropertyChanged
 }
 
-func (progress *progressBarData) String() string {
+func normalizeProgressBarTag(tag PropertyName) PropertyName {
-	return getViewString(progress, nil)
+	tag = defaultNormalize(tag)
-}
-
-func (progress *progressBarData) normalizeTag(tag string) string {
-	tag = strings.ToLower(tag)
 	switch tag {
 	case Max, "progress-bar-max", "progressbar-max":
 		return ProgressBarMax
@@ -70,43 +68,20 @@ func (progress *progressBarData) normalizeTag(tag string) string {
 	return tag
 }
 
-func (progress *progressBarData) Remove(tag string) {
+func progressBarPropertyChanged(view View, tag PropertyName) {
-	progress.remove(progress.normalizeTag(tag))
-}
 
-func (progress *progressBarData) remove(tag string) {
-	progress.viewData.remove(tag)
-	progress.propertyChanged(tag)
-}
-
-func (progress *progressBarData) propertyChanged(tag string) {
-	if progress.created {
 	switch tag {
 	case ProgressBarMax:
-			progress.session.updateProperty(progress.htmlID(), Max,
+		view.Session().updateProperty(view.htmlID(), "max",
-				strconv.FormatFloat(GetProgressBarMax(progress), 'f', -1, 32))
+			strconv.FormatFloat(GetProgressBarMax(view), 'f', -1, 32))
 
 	case ProgressBarValue:
-			progress.session.updateProperty(progress.htmlID(), Value,
+		view.Session().updateProperty(view.htmlID(), "value",
-				strconv.FormatFloat(GetProgressBarValue(progress), 'f', -1, 32))
+			strconv.FormatFloat(GetProgressBarValue(view), 'f', -1, 32))
-		}
-	}
-}
 
-func (progress *progressBarData) Set(tag string, value any) bool {
+	default:
-	return progress.set(progress.normalizeTag(tag), value)
+		viewPropertyChanged(view, tag)
 	}
-
-func (progress *progressBarData) set(tag string, value any) bool {
-	if progress.viewData.set(tag, value) {
-		progress.propertyChanged(tag)
-		return true
-	}
-	return false
-}
-
-func (progress *progressBarData) Get(tag string) any {
-	return progress.get(progress.normalizeTag(tag))
 }
 
 func (progress *progressBarData) htmlTag() string {

properties.go

@@ -9,71 +9,96 @@ import (
 type Properties interface {
 	// Get returns a value of the property with name defined by the argument.
 	// The type of return value depends on the property. If the property is not set then nil is returned.
-	Get(tag string) any
+	Get(tag PropertyName) any
-	getRaw(tag string) any
+	getRaw(tag PropertyName) any
 
 	// Set sets the value (second argument) of the property with name defined by the first argument.
 	// Return "true" if the value has been set, in the opposite case "false" are returned and
 	// a description of the error is written to the log
-	Set(tag string, value any) bool
+	Set(tag PropertyName, value any) bool
-	setRaw(tag string, value any)
+	setRaw(tag PropertyName, value any)
 
 	// Remove removes the property with name defined by the argument
-	Remove(tag string)
+	Remove(tag PropertyName)
 
 	// Clear removes all properties
 	Clear()
 
 	// AllTags returns an array of the set properties
-	AllTags() []string
+	AllTags() []PropertyName
+
+	empty() bool
 }
 
 type propertyList struct {
-	properties map[string]any
+	properties map[PropertyName]any
+	normalize  func(PropertyName) PropertyName
+	//getFunc    func(PropertyName) any
+	//set        func(Properties, PropertyName, any) []PropertyName
+	//remove     func(Properties, PropertyName) []PropertyName
+}
+
+type dataProperty struct {
+	propertyList
+	supportedProperties []PropertyName
+	get                 func(Properties, PropertyName) any
+	set                 func(Properties, PropertyName, any) []PropertyName
+	remove              func(Properties, PropertyName) []PropertyName
+}
+
+func defaultNormalize(tag PropertyName) PropertyName {
+	return PropertyName(strings.ToLower(strings.Trim(string(tag), " \t")))
 }
 
 func (properties *propertyList) init() {
-	properties.properties = map[string]any{}
+	properties.properties = map[PropertyName]any{}
+	properties.normalize = defaultNormalize
+	//properties.getFunc = properties.getRaw
+	//properties.set = propertiesSet
+	//properties.remove = propertiesRemove
 }
 
-func (properties *propertyList) Get(tag string) any {
+func (properties *propertyList) empty() bool {
-	return properties.getRaw(strings.ToLower(tag))
+	return len(properties.properties) == 0
 }
 
-func (properties *propertyList) getRaw(tag string) any {
+func (properties *propertyList) getRaw(tag PropertyName) any {
 	if value, ok := properties.properties[tag]; ok {
 		return value
 	}
 	return nil
 }
 
-func (properties *propertyList) setRaw(tag string, value any) {
+func (properties *propertyList) setRaw(tag PropertyName, value any) {
+	if value == nil {
+		delete(properties.properties, tag)
+	} else {
 		properties.properties[tag] = value
 	}
-
-func (properties *propertyList) Remove(tag string) {
-	delete(properties.properties, strings.ToLower(tag))
 }
 
-func (properties *propertyList) remove(tag string) {
+/*
-	delete(properties.properties, tag)
+	func (properties *propertyList) Remove(tag PropertyName) {
+		properties.remove(properties, properties.normalize(tag))
 	}
-
+*/
 func (properties *propertyList) Clear() {
-	properties.properties = map[string]any{}
+	properties.properties = map[PropertyName]any{}
 }
 
-func (properties *propertyList) AllTags() []string {
+func (properties *propertyList) AllTags() []PropertyName {
-	tags := make([]string, 0, len(properties.properties))
+	tags := make([]PropertyName, 0, len(properties.properties))
-	for t := range properties.properties {
+	for tag := range properties.properties {
-		tags = append(tags, t)
+		tags = append(tags, tag)
 	}
-	sort.Strings(tags)
+	sort.Slice(tags, func(i, j int) bool {
+		return tags[i] < tags[j]
+	})
 	return tags
 }
 
 func (properties *propertyList) writeToBuffer(buffer *strings.Builder,
-	indent string, objectTag string, tags []string) {
+	indent string, objectTag string, tags []PropertyName) {
 
 	buffer.WriteString(objectTag)
 	buffer.WriteString(" {\n")
@@ -83,7 +108,7 @@ func (properties *propertyList) writeToBuffer(buffer *strings.Builder,
 	for _, tag := range tags {
 		if value, ok := properties.properties[tag]; ok {
 			buffer.WriteString(indent2)
-			buffer.WriteString(tag)
+			buffer.WriteString(string(tag))
 			buffer.WriteString(" = ")
 			writePropertyValue(buffer, tag, value, indent2)
 			buffer.WriteString(",\n")
@@ -100,14 +125,41 @@ func parseProperties(properties Properties, object DataObject) {
 		if node := object.Property(i); node != nil {
 			switch node.Type() {
 			case TextNode:
-				properties.Set(node.Tag(), node.Text())
+				properties.Set(PropertyName(node.Tag()), node.Text())
 
 			case ObjectNode:
-				properties.Set(node.Tag(), node.Object())
+				properties.Set(PropertyName(node.Tag()), node.Object())
 
 			case ArrayNode:
-				properties.Set(node.Tag(), node.ArrayElements())
+				properties.Set(PropertyName(node.Tag()), node.ArrayElements())
 			}
 		}
 	}
 }
+
+func propertiesGet(properties Properties, tag PropertyName) any {
+	return properties.getRaw(tag)
+}
+
+func propertiesRemove(properties Properties, tag PropertyName) []PropertyName {
+	if properties.getRaw(tag) == nil {
+		return []PropertyName{}
+	}
+	properties.setRaw(tag, nil)
+	return []PropertyName{tag}
+}
+
+func (data *dataProperty) init() {
+	data.propertyList.init()
+	data.get = propertiesGet
+	data.set = propertiesSet
+	data.remove = propertiesRemove
+}
+
+func (data *dataProperty) Get(tag PropertyName) any {
+	return propertiesGet(data, data.normalize(tag))
+}
+
+func (data *dataProperty) Remove(tag PropertyName) {
+	data.remove(data, data.normalize(tag))
+}

propertyGet.go

@@ -6,7 +6,7 @@ import (
 	"strings"
 )
 
-func stringProperty(properties Properties, tag string, session Session) (string, bool) {
+func stringProperty(properties Properties, tag PropertyName, session Session) (string, bool) {
 	if value := properties.getRaw(tag); value != nil {
 		if text, ok := value.(string); ok {
 			return session.resolveConstants(text)
@@ -15,7 +15,7 @@ func stringProperty(properties Properties, tag string, session Session) (string,
 	return "", false
 }
 
-func imageProperty(properties Properties, tag string, session Session) (string, bool) {
+func imageProperty(properties Properties, tag PropertyName, session Session) (string, bool) {
 	if value := properties.getRaw(tag); value != nil {
 		if text, ok := value.(string); ok {
 			if text != "" && text[0] == '@' {
@@ -61,11 +61,11 @@ func valueToSizeUnit(value any, session Session) (SizeUnit, bool) {
 	return AutoSize(), false
 }
 
-func sizeProperty(properties Properties, tag string, session Session) (SizeUnit, bool) {
+func sizeProperty(properties Properties, tag PropertyName, session Session) (SizeUnit, bool) {
 	return valueToSizeUnit(properties.getRaw(tag), session)
 }
 
-func angleProperty(properties Properties, tag string, session Session) (AngleUnit, bool) {
+func angleProperty(properties Properties, tag PropertyName, session Session) (AngleUnit, bool) {
 	if value := properties.getRaw(tag); value != nil {
 		switch value := value.(type) {
 		case AngleUnit:
@@ -98,11 +98,11 @@ func valueToColor(value any, session Session) (Color, bool) {
 	return Color(0), false
 }
 
-func colorProperty(properties Properties, tag string, session Session) (Color, bool) {
+func colorProperty(properties Properties, tag PropertyName, session Session) (Color, bool) {
 	return valueToColor(properties.getRaw(tag), session)
 }
 
-func valueToEnum(value any, tag string, session Session, defaultValue int) (int, bool) {
+func valueToEnum(value any, tag PropertyName, session Session, defaultValue int) (int, bool) {
 	if value != nil {
 		values := enumProperties[tag].values
 		switch value := value.(type) {
@@ -165,7 +165,7 @@ func enumStringToInt(value string, enumValues []string, logError bool) (int, boo
 	return 0, false
 }
 
-func enumProperty(properties Properties, tag string, session Session, defaultValue int) (int, bool) {
+func enumProperty(properties Properties, tag PropertyName, session Session, defaultValue int) (int, bool) {
 	return valueToEnum(properties.getRaw(tag), tag, session, defaultValue)
 }
 
@@ -194,7 +194,7 @@ func valueToBool(value any, session Session) (bool, bool) {
 	return false, false
 }
 
-func boolProperty(properties Properties, tag string, session Session) (bool, bool) {
+func boolProperty(properties Properties, tag PropertyName, session Session) (bool, bool) {
 	return valueToBool(properties.getRaw(tag), session)
 }
 
@@ -224,7 +224,7 @@ func valueToInt(value any, session Session, defaultValue int) (int, bool) {
 	return defaultValue, false
 }
 
-func intProperty(properties Properties, tag string, session Session, defaultValue int) (int, bool) {
+func intProperty(properties Properties, tag PropertyName, session Session, defaultValue int) (int, bool) {
 	return valueToInt(properties.getRaw(tag), session, defaultValue)
 }
 
@@ -248,7 +248,7 @@ func valueToFloat(value any, session Session, defaultValue float64) (float64, bo
 	return defaultValue, false
 }
 
-func floatProperty(properties Properties, tag string, session Session, defaultValue float64) (float64, bool) {
+func floatProperty(properties Properties, tag PropertyName, session Session, defaultValue float64) (float64, bool) {
 	return valueToFloat(properties.getRaw(tag), session, defaultValue)
 }
 
@@ -272,7 +272,7 @@ func valueToFloatText(value any, session Session, defaultValue float64) (string,
 	return fmt.Sprintf("%g", defaultValue), false
 }
 
-func floatTextProperty(properties Properties, tag string, session Session, defaultValue float64) (string, bool) {
+func floatTextProperty(properties Properties, tag PropertyName, session Session, defaultValue float64) (string, bool) {
 	return valueToFloatText(properties.getRaw(tag), session, defaultValue)
 }
 
@@ -297,6 +297,6 @@ func valueToRange(value any, session Session) (Range, bool) {
 	return Range{}, false
 }
 
-func rangeProperty(properties Properties, tag string, session Session) (Range, bool) {
+func rangeProperty(properties Properties, tag PropertyName, session Session) (Range, bool) {
 	return valueToRange(properties.getRaw(tag), session)
 }

propertySet.go

@@ -6,7 +6,7 @@ import (
 	"strings"
 )
 
-var colorProperties = []string{
+var colorProperties = []PropertyName{
 	ColorTag,
 	BackgroundColor,
 	TextColor,
@@ -21,7 +21,7 @@ var colorProperties = []string{
 	ColorPickerValue,
 }
 
-func isPropertyInList(tag string, list []string) bool {
+func isPropertyInList(tag PropertyName, list []PropertyName) bool {
 	for _, prop := range list {
 		if prop == tag {
 			return true
@@ -30,11 +30,11 @@ func isPropertyInList(tag string, list []string) bool {
 	return false
 }
 
-var angleProperties = []string{
+var angleProperties = []PropertyName{
 	From,
 }
 
-var boolProperties = []string{
+var boolProperties = []PropertyName{
 	Disabled,
 	Focusable,
 	Inset,
@@ -63,7 +63,7 @@ var boolProperties = []string{
 	ColumnSpanAll,
 }
 
-var intProperties = []string{
+var intProperties = []PropertyName{
 	ZIndex,
 	TabSize,
 	HeadHeight,
@@ -73,9 +73,10 @@ var intProperties = []string{
 	ColumnCount,
 	Order,
 	TabIndex,
+	MaxLength,
 }
 
-var floatProperties = map[string]struct{ min, max float64 }{
+var floatProperties = map[PropertyName]struct{ min, max float64 }{
 	Opacity:           {min: 0, max: 1},
 	NumberPickerMax:   {min: -math.MaxFloat64, max: math.MaxFloat64},
 	NumberPickerMin:   {min: -math.MaxFloat64, max: math.MaxFloat64},
@@ -87,79 +88,79 @@ var floatProperties = map[string]struct{ min, max float64 }{
 	VideoHeight:       {min: 0, max: 10000},
 }
 
-var sizeProperties = map[string]string{
+var sizeProperties = map[PropertyName]string{
-	Width:              Width,
+	Width:              string(Width),
-	Height:             Height,
+	Height:             string(Height),
-	MinWidth:           MinWidth,
+	MinWidth:           string(MinWidth),
-	MinHeight:          MinHeight,
+	MinHeight:          string(MinHeight),
-	MaxWidth:           MaxWidth,
+	MaxWidth:           string(MaxWidth),
-	MaxHeight:          MaxHeight,
+	MaxHeight:          string(MaxHeight),
-	Left:               Left,
+	Left:               string(Left),
-	Right:              Right,
+	Right:              string(Right),
-	Top:                Top,
+	Top:                string(Top),
-	Bottom:             Bottom,
+	Bottom:             string(Bottom),
 	TextSize:           "font-size",
-	TextIndent:         TextIndent,
+	TextIndent:         string(TextIndent),
-	LetterSpacing:      LetterSpacing,
+	LetterSpacing:      string(LetterSpacing),
-	WordSpacing:        WordSpacing,
+	WordSpacing:        string(WordSpacing),
-	LineHeight:         LineHeight,
+	LineHeight:         string(LineHeight),
 	TextLineThickness:  "text-decoration-thickness",
 	ListRowGap:         "row-gap",
 	ListColumnGap:      "column-gap",
-	GridRowGap:         GridRowGap,
+	GridRowGap:         string(GridRowGap),
-	GridColumnGap:      GridColumnGap,
+	GridColumnGap:      string(GridColumnGap),
-	ColumnWidth:        ColumnWidth,
+	ColumnWidth:        string(ColumnWidth),
-	ColumnGap:          ColumnGap,
+	ColumnGap:          string(ColumnGap),
-	Gap:                Gap,
+	Gap:                string(Gap),
-	Margin:             Margin,
+	Margin:             string(Margin),
-	MarginLeft:         MarginLeft,
+	MarginLeft:         string(MarginLeft),
-	MarginRight:        MarginRight,
+	MarginRight:        string(MarginRight),
-	MarginTop:          MarginTop,
+	MarginTop:          string(MarginTop),
-	MarginBottom:       MarginBottom,
+	MarginBottom:       string(MarginBottom),
-	Padding:            Padding,
+	Padding:            string(Padding),
-	PaddingLeft:        PaddingLeft,
+	PaddingLeft:        string(PaddingLeft),
-	PaddingRight:       PaddingRight,
+	PaddingRight:       string(PaddingRight),
-	PaddingTop:         PaddingTop,
+	PaddingTop:         string(PaddingTop),
-	PaddingBottom:      PaddingBottom,
+	PaddingBottom:      string(PaddingBottom),
-	BorderWidth:        BorderWidth,
+	BorderWidth:        string(BorderWidth),
-	BorderLeftWidth:    BorderLeftWidth,
+	BorderLeftWidth:    string(BorderLeftWidth),
-	BorderRightWidth:   BorderRightWidth,
+	BorderRightWidth:   string(BorderRightWidth),
-	BorderTopWidth:     BorderTopWidth,
+	BorderTopWidth:     string(BorderTopWidth),
-	BorderBottomWidth:  BorderBottomWidth,
+	BorderBottomWidth:  string(BorderBottomWidth),
-	OutlineWidth:       OutlineWidth,
+	OutlineWidth:       string(OutlineWidth),
-	OutlineOffset:      OutlineOffset,
+	OutlineOffset:      string(OutlineOffset),
-	XOffset:            XOffset,
+	XOffset:            string(XOffset),
-	YOffset:            YOffset,
+	YOffset:            string(YOffset),
-	BlurRadius:         BlurRadius,
+	BlurRadius:         string(BlurRadius),
-	SpreadRadius:       SpreadRadius,
+	SpreadRadius:       string(SpreadRadius),
-	Perspective:        Perspective,
+	Perspective:        string(Perspective),
-	PerspectiveOriginX: PerspectiveOriginX,
+	PerspectiveOriginX: string(PerspectiveOriginX),
-	PerspectiveOriginY: PerspectiveOriginY,
+	PerspectiveOriginY: string(PerspectiveOriginY),
-	OriginX:            OriginX,
+	OriginX:            string(OriginX),
-	OriginY:            OriginY,
+	OriginY:            string(OriginY),
-	OriginZ:            OriginZ,
+	OriginZ:            string(OriginZ),
-	Radius:             Radius,
+	Radius:             string(Radius),
-	RadiusX:            RadiusX,
+	RadiusX:            string(RadiusX),
-	RadiusY:            RadiusY,
+	RadiusY:            string(RadiusY),
-	RadiusTopLeft:      RadiusTopLeft,
+	RadiusTopLeft:      string(RadiusTopLeft),
-	RadiusTopLeftX:     RadiusTopLeftX,
+	RadiusTopLeftX:     string(RadiusTopLeftX),
-	RadiusTopLeftY:     RadiusTopLeftY,
+	RadiusTopLeftY:     string(RadiusTopLeftY),
-	RadiusTopRight:     RadiusTopRight,
+	RadiusTopRight:     string(RadiusTopRight),
-	RadiusTopRightX:    RadiusTopRightX,
+	RadiusTopRightX:    string(RadiusTopRightX),
-	RadiusTopRightY:    RadiusTopRightY,
+	RadiusTopRightY:    string(RadiusTopRightY),
-	RadiusBottomLeft:   RadiusBottomLeft,
+	RadiusBottomLeft:   string(RadiusBottomLeft),
-	RadiusBottomLeftX:  RadiusBottomLeftX,
+	RadiusBottomLeftX:  string(RadiusBottomLeftX),
-	RadiusBottomLeftY:  RadiusBottomLeftY,
+	RadiusBottomLeftY:  string(RadiusBottomLeftY),
-	RadiusBottomRight:  RadiusBottomRight,
+	RadiusBottomRight:  string(RadiusBottomRight),
-	RadiusBottomRightX: RadiusBottomRightX,
+	RadiusBottomRightX: string(RadiusBottomRightX),
-	RadiusBottomRightY: RadiusBottomRightY,
+	RadiusBottomRightY: string(RadiusBottomRightY),
-	ItemWidth:          ItemWidth,
+	ItemWidth:          string(ItemWidth),
-	ItemHeight:         ItemHeight,
+	ItemHeight:         string(ItemHeight),
-	CenterX:            CenterX,
+	CenterX:            string(CenterX),
-	CenterY:            CenterX,
+	CenterY:            string(CenterX),
 }
 
-var enumProperties = map[string]struct {
+var enumProperties = map[PropertyName]struct {
 	values    []string
 	cssTag    string
 	cssValues []string
@@ -176,17 +177,17 @@ var enumProperties = map[string]struct {
 	},
 	Overflow: {
 		[]string{"hidden", "visible", "scroll", "auto"},
-		Overflow,
+		string(Overflow),
 		[]string{"hidden", "visible", "scroll", "auto"},
 	},
 	TextAlign: {
 		[]string{"left", "right", "center", "justify"},
-		TextAlign,
+		string(TextAlign),
 		[]string{"left", "right", "center", "justify"},
 	},
 	TextTransform: {
 		[]string{"none", "capitalize", "lowercase", "uppercase"},
-		TextTransform,
+		string(TextTransform),
 		[]string{"none", "capitalize", "lowercase", "uppercase"},
 	},
 	TextWeight: {
@@ -196,27 +197,27 @@ var enumProperties = map[string]struct {
 	},
 	WhiteSpace: {
 		[]string{"normal", "nowrap", "pre", "pre-wrap", "pre-line", "break-spaces"},
-		WhiteSpace,
+		string(WhiteSpace),
 		[]string{"normal", "nowrap", "pre", "pre-wrap", "pre-line", "break-spaces"},
 	},
 	WordBreak: {
 		[]string{"normal", "break-all", "keep-all", "break-word"},
-		WordBreak,
+		string(WordBreak),
 		[]string{"normal", "break-all", "keep-all", "break-word"},
 	},
 	TextOverflow: {
 		[]string{"clip", "ellipsis"},
-		TextOverflow,
+		string(TextOverflow),
 		[]string{"clip", "ellipsis"},
 	},
 	TextWrap: {
 		[]string{"wrap", "nowrap", "balance"},
-		TextWrap,
+		string(TextWrap),
 		[]string{"wrap", "nowrap", "balance"},
 	},
 	WritingMode: {
 		[]string{"horizontal-top-to-bottom", "horizontal-bottom-to-top", "vertical-right-to-left", "vertical-left-to-right"},
-		WritingMode,
+		string(WritingMode),
 		[]string{"horizontal-tb", "horizontal-bt", "vertical-rl", "vertical-lr"},
 	},
 	TextDirection: {
@@ -236,7 +237,7 @@ var enumProperties = map[string]struct {
 	},
 	BorderStyle: {
 		[]string{"none", "solid", "dashed", "dotted", "double"},
-		BorderStyle,
+		string(BorderStyle),
 		[]string{"none", "solid", "dashed", "dotted", "double"},
 	},
 	TopStyle: {
@@ -261,7 +262,7 @@ var enumProperties = map[string]struct {
 	},
 	OutlineStyle: {
 		[]string{"none", "solid", "dashed", "dotted", "double"},
-		OutlineStyle,
+		string(OutlineStyle),
 		[]string{"none", "solid", "dashed", "dotted", "double"},
 	},
 	Tabs: {
@@ -336,7 +337,7 @@ var enumProperties = map[string]struct {
 	},
 	GridAutoFlow: {
 		[]string{"row", "column", "row-dense", "column-dense"},
-		GridAutoFlow,
+		string(GridAutoFlow),
 		[]string{"row", "column", "row dense", "column dense"},
 	},
 	ImageVerticalAlign: {
@@ -376,7 +377,7 @@ var enumProperties = map[string]struct {
 	},
 	Cursor: {
 		[]string{"auto", "default", "none", "context-menu", "help", "pointer", "progress", "wait", "cell", "crosshair", "text", "vertical-text", "alias", "copy", "move", "no-drop", "not-allowed", "e-resize", "n-resize", "ne-resize", "nw-resize", "s-resize", "se-resize", "sw-resize", "w-resize", "ew-resize", "ns-resize", "nesw-resize", "nwse-resize", "col-resize", "row-resize", "all-scroll", "zoom-in", "zoom-out", "grab", "grabbing"},
-		Cursor,
+		string(Cursor),
 		[]string{"auto", "default", "none", "context-menu", "help", "pointer", "progress", "wait", "cell", "crosshair", "text", "vertical-text", "alias", "copy", "move", "no-drop", "not-allowed", "e-resize", "n-resize", "ne-resize", "nw-resize", "s-resize", "se-resize", "sw-resize", "w-resize", "ew-resize", "ns-resize", "nesw-resize", "nwse-resize", "col-resize", "row-resize", "all-scroll", "zoom-in", "zoom-out", "grab", "grabbing"},
 	},
 	Fit: {
@@ -456,27 +457,27 @@ var enumProperties = map[string]struct {
 	},
 	MixBlendMode: {
 		[]string{"normal", "multiply", "screen", "overlay", "darken", "lighten", "color-dodge", "color-burn", "hard-light", "soft-light", "difference", "exclusion", "hue", "saturation", "color", "luminosity"},
-		MixBlendMode,
+		string(MixBlendMode),
 		[]string{"normal", "multiply", "screen", "overlay", "darken", "lighten", "color-dodge", "color-burn", "hard-light", "soft-light", "difference", "exclusion", "hue", "saturation", "color", "luminosity"},
 	},
 	BackgroundBlendMode: {
 		[]string{"normal", "multiply", "screen", "overlay", "darken", "lighten", "color-dodge", "color-burn", "hard-light", "soft-light", "difference", "exclusion", "hue", "saturation", "color", "luminosity"},
-		BackgroundBlendMode,
+		string(BackgroundBlendMode),
 		[]string{"normal", "multiply", "screen", "overlay", "darken", "lighten", "color-dodge", "color-burn", "hard-light", "soft-light", "difference", "exclusion", "hue", "saturation", "color", "luminosity"},
 	},
 	ColumnFill: {
 		[]string{"balance", "auto"},
-		ColumnFill,
+		string(ColumnFill),
 		[]string{"balance", "auto"},
 	},
 }
 
-func notCompatibleType(tag string, value any) {
+func notCompatibleType(tag PropertyName, value any) {
-	ErrorLogF(`"%T" type not compatible with "%s" property`, value, tag)
+	ErrorLogF(`"%T" type not compatible with "%s" property`, value, string(tag))
 }
 
-func invalidPropertyValue(tag string, value any) {
+func invalidPropertyValue(tag PropertyName, value any) {
-	ErrorLogF(`Invalid value "%v" of "%s" property`, value, tag)
+	ErrorLogF(`Invalid value "%v" of "%s" property`, value, string(tag))
 }
 
 func isConstantName(text string) bool {
@@ -537,26 +538,48 @@ func isInt(value any) (int, bool) {
 	return n, true
 }
 
-func (properties *propertyList) setSimpleProperty(tag string, value any) bool {
+func setSimpleProperty(properties Properties, tag PropertyName, value any) bool {
 	if value == nil {
-		delete(properties.properties, tag)
+		properties.setRaw(tag, nil)
 		return true
 	} else if text, ok := value.(string); ok {
 		text = strings.Trim(text, " \t\n\r")
 		if text == "" {
-			delete(properties.properties, tag)
+			properties.setRaw(tag, nil)
 			return true
 		}
 		if isConstantName(text) {
-			properties.properties[tag] = text
+			properties.setRaw(tag, text)
 			return true
 		}
 	}
 	return false
 }
 
-func (properties *propertyList) setSizeProperty(tag string, value any) bool {
+func setStringPropertyValue(properties Properties, tag PropertyName, text any) []PropertyName {
-	if !properties.setSimpleProperty(tag, value) {
+	if text != "" {
+		properties.setRaw(tag, text)
+	} else if properties.getRaw(tag) != nil {
+		properties.setRaw(tag, nil)
+	} else {
+		return []PropertyName{}
+	}
+	return []PropertyName{tag}
+}
+
+func setArrayPropertyValue[T any](properties Properties, tag PropertyName, value []T) []PropertyName {
+	if len(value) > 0 {
+		properties.setRaw(tag, value)
+	} else if properties.getRaw(tag) != nil {
+		properties.setRaw(tag, nil)
+	} else {
+		return []PropertyName{}
+	}
+	return []PropertyName{tag}
+}
+
+func setSizeProperty(properties Properties, tag PropertyName, value any) []PropertyName {
+	if !setSimpleProperty(properties, tag, value) {
 		var size SizeUnit
 		switch value := value.(type) {
 		case string:
@@ -566,7 +589,7 @@ func (properties *propertyList) setSizeProperty(tag string, value any) bool {
 				size.Function = fn
 			} else if size, ok = StringToSizeUnit(value); !ok {
 				invalidPropertyValue(tag, value)
-				return false
+				return nil
 			}
 		case SizeUnit:
 			size = value
@@ -589,29 +612,29 @@ func (properties *propertyList) setSizeProperty(tag string, value any) bool {
 				size.Value = float64(n)
 			} else {
 				notCompatibleType(tag, value)
-				return false
+				return nil
 			}
 		}
 
 		if size.Type == Auto {
-			delete(properties.properties, tag)
+			properties.setRaw(tag, nil)
 		} else {
-			properties.properties[tag] = size
+			properties.setRaw(tag, size)
 		}
 	}
 
-	return true
+	return []PropertyName{tag}
 }
 
-func (properties *propertyList) setAngleProperty(tag string, value any) bool {
+func setAngleProperty(properties Properties, tag PropertyName, value any) []PropertyName {
-	if !properties.setSimpleProperty(tag, value) {
+	if !setSimpleProperty(properties, tag, value) {
 		var angle AngleUnit
 		switch value := value.(type) {
 		case string:
 			var ok bool
 			if angle, ok = StringToAngleUnit(value); !ok {
 				invalidPropertyValue(tag, value)
-				return false
+				return nil
 			}
 		case AngleUnit:
 			angle = value
@@ -627,24 +650,24 @@ func (properties *propertyList) setAngleProperty(tag string, value any) bool {
 				angle = Rad(float64(n))
 			} else {
 				notCompatibleType(tag, value)
-				return false
+				return nil
 			}
 		}
-		properties.properties[tag] = angle
+		properties.setRaw(tag, angle)
 	}
 
-	return true
+	return []PropertyName{tag}
 }
 
-func (properties *propertyList) setColorProperty(tag string, value any) bool {
+func setColorProperty(properties Properties, tag PropertyName, value any) []PropertyName {
-	if !properties.setSimpleProperty(tag, value) {
+	if !setSimpleProperty(properties, tag, value) {
 		var result Color
 		switch value := value.(type) {
 		case string:
 			var err error
 			if result, err = stringToColor(value); err != nil {
 				invalidPropertyValue(tag, value)
-				return false
+				return nil
 			}
 		case Color:
 			result = value
@@ -654,105 +677,101 @@ func (properties *propertyList) setColorProperty(tag string, value any) bool {
 				result = Color(color)
 			} else {
 				notCompatibleType(tag, value)
-				return false
+				return nil
 			}
 		}
 
-		if result == 0 {
+		properties.setRaw(tag, result)
-			delete(properties.properties, tag)
-		} else {
-			properties.properties[tag] = result
-		}
 	}
 
-	return true
+	return []PropertyName{tag}
 }
 
-func (properties *propertyList) setEnumProperty(tag string, value any, values []string) bool {
+func setEnumProperty(properties Properties, tag PropertyName, value any, values []string) []PropertyName {
-	if !properties.setSimpleProperty(tag, value) {
+	if !setSimpleProperty(properties, tag, value) {
 		var n int
 		if text, ok := value.(string); ok {
 			if n, ok = enumStringToInt(text, values, false); !ok {
 				invalidPropertyValue(tag, value)
-				return false
+				return nil
 			}
 		} else if i, ok := isInt(value); ok {
 			if i < 0 || i >= len(values) {
 				invalidPropertyValue(tag, value)
-				return false
+				return nil
 			}
 			n = i
 		} else {
 			notCompatibleType(tag, value)
-			return false
+			return nil
 		}
 
-		properties.properties[tag] = n
+		properties.setRaw(tag, n)
 	}
 
-	return true
+	return []PropertyName{tag}
 }
 
-func (properties *propertyList) setBoolProperty(tag string, value any) bool {
+func setBoolProperty(properties Properties, tag PropertyName, value any) []PropertyName {
-	if !properties.setSimpleProperty(tag, value) {
+	if !setSimpleProperty(properties, tag, value) {
 		if text, ok := value.(string); ok {
 			switch strings.ToLower(strings.Trim(text, " \t")) {
 			case "true", "yes", "on", "1":
-				properties.properties[tag] = true
+				properties.setRaw(tag, true)
 
 			case "false", "no", "off", "0":
-				properties.properties[tag] = false
+				properties.setRaw(tag, false)
 
 			default:
 				invalidPropertyValue(tag, value)
-				return false
+				return nil
 			}
 		} else if n, ok := isInt(value); ok {
 			switch n {
 			case 1:
-				properties.properties[tag] = true
+				properties.setRaw(tag, true)
 
 			case 0:
-				properties.properties[tag] = false
+				properties.setRaw(tag, false)
 
 			default:
 				invalidPropertyValue(tag, value)
-				return false
+				return nil
 			}
 		} else if b, ok := value.(bool); ok {
-			properties.properties[tag] = b
+			properties.setRaw(tag, b)
 		} else {
 			notCompatibleType(tag, value)
-			return false
+			return nil
 		}
 	}
 
-	return true
+	return []PropertyName{tag}
 }
 
-func (properties *propertyList) setIntProperty(tag string, value any) bool {
+func setIntProperty(properties Properties, tag PropertyName, value any) []PropertyName {
-	if !properties.setSimpleProperty(tag, value) {
+	if !setSimpleProperty(properties, tag, value) {
 		if text, ok := value.(string); ok {
 			n, err := strconv.Atoi(strings.Trim(text, " \t"))
 			if err != nil {
 				invalidPropertyValue(tag, value)
 				ErrorLog(err.Error())
-				return false
+				return nil
 			}
-			properties.properties[tag] = n
+			properties.setRaw(tag, n)
 		} else if n, ok := isInt(value); ok {
-			properties.properties[tag] = n
+			properties.setRaw(tag, n)
 		} else {
 			notCompatibleType(tag, value)
-			return false
+			return nil
 		}
 	}
 
-	return true
+	return []PropertyName{tag}
 }
 
-func (properties *propertyList) setFloatProperty(tag string, value any, min, max float64) bool {
+func setFloatProperty(properties Properties, tag PropertyName, value any, min, max float64) []PropertyName {
-	if !properties.setSimpleProperty(tag, value) {
+	if !setSimpleProperty(properties, tag, value) {
 		f := float64(0)
 		switch value := value.(type) {
 		case string:
@@ -760,14 +779,14 @@ func (properties *propertyList) setFloatProperty(tag string, value any, min, max
 			if f, err = strconv.ParseFloat(strings.Trim(value, " \t"), 64); err != nil {
 				invalidPropertyValue(tag, value)
 				ErrorLog(err.Error())
-				return false
+				return nil
 			}
 			if f < min || f > max {
 				ErrorLogF(`"%T" out of range of "%s" property`, value, tag)
-				return false
+				return nil
 			}
-			properties.properties[tag] = value
+			properties.setRaw(tag, value)
-			return true
+			return nil
 
 		case float32:
 			f = float64(value)
@@ -780,64 +799,84 @@ func (properties *propertyList) setFloatProperty(tag string, value any, min, max
 				f = float64(n)
 			} else {
 				notCompatibleType(tag, value)
-				return false
+				return nil
 			}
 		}
 
 		if f >= min && f <= max {
-			properties.properties[tag] = f
+			properties.setRaw(tag, f)
 		} else {
 			ErrorLogF(`"%T" out of range of "%s" property`, value, tag)
-			return false
+			return nil
 		}
 	}
 
-	return true
+	return []PropertyName{tag}
-}
-
-func (properties *propertyList) Set(tag string, value any) bool {
-	return properties.set(strings.ToLower(tag), value)
-}
-
-func (properties *propertyList) set(tag string, value any) bool {
-	if value == nil {
-		delete(properties.properties, tag)
-		return true
 }
 
+func propertiesSet(properties Properties, tag PropertyName, value any) []PropertyName {
 	if _, ok := sizeProperties[tag]; ok {
-		return properties.setSizeProperty(tag, value)
+		return setSizeProperty(properties, tag, value)
 	}
 
 	if valuesData, ok := enumProperties[tag]; ok {
-		return properties.setEnumProperty(tag, value, valuesData.values)
+		return setEnumProperty(properties, tag, value, valuesData.values)
 	}
 
 	if limits, ok := floatProperties[tag]; ok {
-		return properties.setFloatProperty(tag, value, limits.min, limits.max)
+		return setFloatProperty(properties, tag, value, limits.min, limits.max)
 	}
 
 	if isPropertyInList(tag, colorProperties) {
-		return properties.setColorProperty(tag, value)
+		return setColorProperty(properties, tag, value)
 	}
 
 	if isPropertyInList(tag, angleProperties) {
-		return properties.setAngleProperty(tag, value)
+		return setAngleProperty(properties, tag, value)
 	}
 
 	if isPropertyInList(tag, boolProperties) {
-		return properties.setBoolProperty(tag, value)
+		return setBoolProperty(properties, tag, value)
 	}
 
 	if isPropertyInList(tag, intProperties) {
-		return properties.setIntProperty(tag, value)
+		return setIntProperty(properties, tag, value)
 	}
 
 	if text, ok := value.(string); ok {
-		properties.properties[tag] = text
+		properties.setRaw(tag, text)
-		return true
+		return []PropertyName{tag}
 	}
 
 	notCompatibleType(tag, value)
+	return nil
+}
+
+/*
+func (properties *propertyList) Set(tag PropertyName, value any) bool {
+	tag = properties.normalize(tag)
+	if value == nil {
+		properties.remove(properties, tag)
+		return true
+	}
+
+	return properties.set(properties, tag, value) != nil
+}
+*/
+
+func (data *dataProperty) Set(tag PropertyName, value any) bool {
+	if value == nil {
+		data.Remove(tag)
+		return true
+	}
+
+	tag = data.normalize(tag)
+	for _, supported := range data.supportedProperties {
+		if tag == supported {
+			return data.set(data, tag, value) != nil
+		}
+	}
+
+	ErrorLogF(`"%s" property is not supported`, string(tag))
 	return false
 }

radius.go

@@ -37,7 +37,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	Radius = "radius"
+	Radius PropertyName = "radius"
 
 	// RadiusX is the constant for "radius-x" property tag.
 	//
@@ -58,7 +58,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusX = "radius-x"
+	RadiusX PropertyName = "radius-x"
 
 	// RadiusY is the constant for "radius-y" property tag.
 	//
@@ -79,7 +79,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusY = "radius-y"
+	RadiusY PropertyName = "radius-y"
 
 	// RadiusTopLeft is the constant for "radius-top-left" property tag.
 	//
@@ -90,7 +90,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusTopLeft = "radius-top-left"
+	RadiusTopLeft PropertyName = "radius-top-left"
 
 	// RadiusTopLeftX is the constant for "radius-top-left-x" property tag.
 	//
@@ -101,7 +101,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusTopLeftX = "radius-top-left-x"
+	RadiusTopLeftX PropertyName = "radius-top-left-x"
 
 	// RadiusTopLeftY is the constant for "radius-top-left-y" property tag.
 	//
@@ -112,7 +112,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusTopLeftY = "radius-top-left-y"
+	RadiusTopLeftY PropertyName = "radius-top-left-y"
 
 	// RadiusTopRight is the constant for "radius-top-right" property tag.
 	//
@@ -123,7 +123,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusTopRight = "radius-top-right"
+	RadiusTopRight PropertyName = "radius-top-right"
 
 	// RadiusTopRightX is the constant for "radius-top-right-x" property tag.
 	//
@@ -134,7 +134,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusTopRightX = "radius-top-right-x"
+	RadiusTopRightX PropertyName = "radius-top-right-x"
 
 	// RadiusTopRightY is the constant for "radius-top-right-y" property tag.
 	//
@@ -145,7 +145,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusTopRightY = "radius-top-right-y"
+	RadiusTopRightY PropertyName = "radius-top-right-y"
 
 	// RadiusBottomLeft is the constant for "radius-bottom-left" property tag.
 	//
@@ -156,7 +156,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusBottomLeft = "radius-bottom-left"
+	RadiusBottomLeft PropertyName = "radius-bottom-left"
 
 	// RadiusBottomLeftX is the constant for "radius-bottom-left-x" property tag.
 	//
@@ -167,7 +167,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusBottomLeftX = "radius-bottom-left-x"
+	RadiusBottomLeftX PropertyName = "radius-bottom-left-x"
 
 	// RadiusBottomLeftY is the constant for "radius-bottom-left-y" property tag.
 	//
@@ -178,7 +178,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusBottomLeftY = "radius-bottom-left-y"
+	RadiusBottomLeftY PropertyName = "radius-bottom-left-y"
 
 	// RadiusBottomRight is the constant for "radius-bottom-right" property tag.
 	//
@@ -189,7 +189,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusBottomRight = "radius-bottom-right"
+	RadiusBottomRight PropertyName = "radius-bottom-right"
 
 	// RadiusBottomRightX is the constant for "radius-bottom-right-x" property tag.
 	//
@@ -200,7 +200,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusBottomRightX = "radius-bottom-right-x"
+	RadiusBottomRightX PropertyName = "radius-bottom-right-x"
 
 	// RadiusBottomRightY is the constant for "radius-bottom-right-y" property tag.
 	//
@@ -211,7 +211,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	RadiusBottomRightY = "radius-bottom-right-y"
+	RadiusBottomRightY PropertyName = "radius-bottom-right-y"
 
 	// X is the constant for "x" property tag.
 	//
@@ -232,7 +232,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	X = "x"
+	X PropertyName = "x"
 
 	// Y is the constant for "y" property tag.
 	//
@@ -253,7 +253,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	Y = "y"
+	Y PropertyName = "y"
 
 	// TopLeft is the constant for "top-left" property tag.
 	//
@@ -264,7 +264,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	TopLeft = "top-left"
+	TopLeft PropertyName = "top-left"
 
 	// TopLeftX is the constant for "top-left-x" property tag.
 	//
@@ -275,7 +275,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	TopLeftX = "top-left-x"
+	TopLeftX PropertyName = "top-left-x"
 
 	// TopLeftY is the constant for "top-left-y" property tag.
 	//
@@ -286,7 +286,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	TopLeftY = "top-left-y"
+	TopLeftY PropertyName = "top-left-y"
 
 	// TopRight is the constant for "top-right" property tag.
 	//
@@ -297,7 +297,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	TopRight = "top-right"
+	TopRight PropertyName = "top-right"
 
 	// TopRightX is the constant for "top-right-x" property tag.
 	//
@@ -308,7 +308,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	TopRightX = "top-right-x"
+	TopRightX PropertyName = "top-right-x"
 
 	// TopRightY is the constant for "top-right-y" property tag.
 	//
@@ -319,7 +319,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	TopRightY = "top-right-y"
+	TopRightY PropertyName = "top-right-y"
 
 	// BottomLeft is the constant for "bottom-left" property tag.
 	//
@@ -330,7 +330,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	BottomLeft = "bottom-left"
+	BottomLeft PropertyName = "bottom-left"
 
 	// BottomLeftX is the constant for "bottom-left-x" property tag.
 	//
@@ -341,7 +341,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	BottomLeftX = "bottom-left-x"
+	BottomLeftX PropertyName = "bottom-left-x"
 
 	// BottomLeftY is the constant for "bottom-left-y" property tag.
 	//
@@ -352,7 +352,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	BottomLeftY = "bottom-left-y"
+	BottomLeftY PropertyName = "bottom-left-y"
 
 	// BottomRight is the constant for "bottom-right" property tag.
 	//
@@ -363,7 +363,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	BottomRight = "bottom-right"
+	BottomRight PropertyName = "bottom-right"
 
 	// BottomRightX is the constant for "bottom-right-x" property tag.
 	//
@@ -374,7 +374,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	BottomRightX = "bottom-right-x"
+	BottomRightX PropertyName = "bottom-right-x"
 
 	// BottomRightY is the constant for "bottom-right-y" property tag.
 	//
@@ -385,7 +385,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	BottomRightY = "bottom-right-y"
+	BottomRightY PropertyName = "bottom-right-y"
 )
 
 // RadiusProperty is a description of the [View] (shape) elliptical corner radius.
@@ -399,38 +399,46 @@ type RadiusProperty interface {
 }
 
 type radiusPropertyData struct {
-	propertyList
+	dataProperty
 }
 
 // NewRadiusProperty creates the new RadiusProperty
 func NewRadiusProperty(params Params) RadiusProperty {
 	result := new(radiusPropertyData)
-	result.properties = map[string]any{}
+	result.dataProperty.init()
+	result.normalize = radiusPropertyNormalize
+	result.get = radiusPropertyGet
+	result.remove = radiusPropertyRemove
+	result.set = radiusPropertySet
+	result.supportedProperties = []PropertyName{
+		X, Y, TopLeft, TopRight, BottomLeft, BottomRight, TopLeftX, TopLeftY,
+		TopRightX, TopRightY, BottomLeftX, BottomLeftY, BottomRightX, BottomRightY,
+	}
+
 	if params != nil {
-		for _, tag := range []string{X, Y, TopLeft, TopRight, BottomLeft, BottomRight, TopLeftX, TopLeftY,
+		for _, tag := range result.supportedProperties {
-			TopRightX, TopRightY, BottomLeftX, BottomLeftY, BottomRightX, BottomRightY} {
 			if value, ok := params[tag]; ok {
-				result.Set(tag, value)
+				radiusPropertySet(result, tag, value)
 			}
 		}
 	}
 	return result
 }
 
-func (radius *radiusPropertyData) normalizeTag(tag string) string {
+func radiusPropertyNormalize(tag PropertyName) PropertyName {
-	return strings.TrimPrefix(strings.ToLower(tag), "radius-")
+	name := strings.TrimPrefix(strings.ToLower(string(tag)), "radius-")
+	return PropertyName(name)
 }
 
 func (radius *radiusPropertyData) writeString(buffer *strings.Builder, indent string) {
 	buffer.WriteString("_{ ")
 	comma := false
-	for _, tag := range []string{X, Y, TopLeft, TopLeftX, TopLeftY, TopRight, TopRightX, TopRightY,
+	for _, tag := range radius.supportedProperties {
-		BottomLeft, BottomLeftX, BottomLeftY, BottomRight, BottomRightX, BottomRightY} {
 		if value, ok := radius.properties[tag]; ok {
 			if comma {
 				buffer.WriteString(", ")
 			}
-			buffer.WriteString(tag)
+			buffer.WriteString(string(tag))
 			buffer.WriteString(" = ")
 			writePropertyValue(buffer, tag, value, indent)
 			comma = true
@@ -444,26 +452,54 @@ func (radius *radiusPropertyData) String() string {
 	return runStringWriter(radius)
 }
 
-func (radius *radiusPropertyData) delete(tags []string) {
+func radiusPropertyRemove(properties Properties, tag PropertyName) []PropertyName {
-	for _, tag := range tags {
+	result := []PropertyName{}
-		delete(radius.properties, tag)
+	removeTag := func(tag PropertyName) {
+		if properties.getRaw(tag) != nil {
+			properties.setRaw(tag, nil)
+			result = append(result, tag)
 		}
 	}
 
-func (radius *radiusPropertyData) deleteUnusedTags() {
+	switch tag {
-	for _, tag := range []string{X, Y} {
+	case X, Y:
-		if _, ok := radius.properties[tag]; ok {
+		if properties.getRaw(tag) == nil {
+			for _, prefix := range []PropertyName{TopLeft, TopRight, BottomLeft, BottomRight} {
+				removeTag(prefix + "-" + tag)
+			}
+		} else {
+			removeTag(tag)
+		}
+
+	case TopLeftX, TopLeftY, TopRightX, TopRightY, BottomLeftX, BottomLeftY, BottomRightX, BottomRightY:
+		removeTag(tag)
+
+	case TopLeft, TopRight, BottomLeft, BottomRight:
+		for _, tag := range []PropertyName{tag, tag + "-x", tag + "-y"} {
+			removeTag(tag)
+		}
+
+	default:
+		ErrorLogF(`"%s" property is not compatible with the RadiusProperty`, tag)
+	}
+
+	return result
+}
+
+func deleteRadiusUnusedTags(radius Properties, result []PropertyName) {
+
+	for _, tag := range []PropertyName{X, Y} {
+		if radius.getRaw(tag) != nil {
 			unused := true
-			for _, t := range []string{TopLeft, TopRight, BottomLeft, BottomRight} {
+			for _, t := range []PropertyName{TopLeft, TopRight, BottomLeft, BottomRight} {
-				if _, ok := radius.properties[t+"-"+tag]; !ok {
+				if radius.getRaw(t+"-"+tag) == nil && radius.getRaw(t) == nil {
-					if _, ok := radius.properties[t]; !ok {
 					unused = false
 					break
 				}
 			}
-			}
 			if unused {
-				delete(radius.properties, tag)
+				radius.setRaw(tag, nil)
+				result = append(result, tag)
 			}
 		}
 	}
@@ -485,124 +521,122 @@ func (radius *radiusPropertyData) deleteUnusedTags() {
 		return false
 	}
 
-	for _, tag := range []string{TopLeft, TopRight, BottomLeft, BottomRight} {
+	for _, tag := range []PropertyName{TopLeft, TopRight, BottomLeft, BottomRight} {
 		tagX := tag + "-x"
 		tagY := tag + "-y"
-		valueX, okX := radius.properties[tagX]
+		valueX := radius.getRaw(tagX)
-		valueY, okY := radius.properties[tagY]
+		valueY := radius.getRaw(tagY)
 
-		if value, ok := radius.properties[tag]; ok {
+		if value := radius.getRaw(tag); value != nil {
-			if okX && okY {
+			if valueX != nil && valueY != nil {
-				delete(radius.properties, tag)
+				radius.setRaw(tag, nil)
-			} else if okX && !okY {
+				result = append(result, tag)
+			} else if valueX != nil && valueY == nil {
 				if equalValue(value, valueX) {
-					delete(radius.properties, tagX)
+					radius.setRaw(tagX, nil)
+					result = append(result, tagX)
 				} else {
-					radius.properties[tagY] = value
+					radius.setRaw(tagY, value)
-					delete(radius.properties, tag)
+					result = append(result, tagY)
+					radius.setRaw(tag, nil)
+					result = append(result, tag)
 				}
-			} else if !okX && okY {
+			} else if valueX == nil && valueY != nil {
 				if equalValue(value, valueY) {
-					delete(radius.properties, tagY)
+					radius.setRaw(tagY, nil)
+					result = append(result, tagY)
 				} else {
-					radius.properties[tagX] = value
+					radius.setRaw(tagX, value)
-					delete(radius.properties, tag)
+					result = append(result, tagX)
+					radius.setRaw(tag, nil)
+					result = append(result, tag)
 				}
 			}
-		} else if okX && okY && equalValue(valueX, valueY) {
+		} else if valueX != nil && valueY != nil && equalValue(valueX, valueY) {
-			radius.properties[tag] = valueX
+			radius.setRaw(tag, valueX)
-			delete(radius.properties, tagX)
+			result = append(result, tag)
-			delete(radius.properties, tagY)
+			radius.setRaw(tagX, nil)
+			result = append(result, tagX)
+			radius.setRaw(tagY, nil)
+			result = append(result, tagY)
 		}
 	}
 }
 
-func (radius *radiusPropertyData) Remove(tag string) {
+func radiusPropertySet(radius Properties, tag PropertyName, value any) []PropertyName {
-	tag = radius.normalizeTag(tag)
+	var result []PropertyName = nil
 
-	switch tag {
+	deleteTags := func(tags []PropertyName) {
-	case X, Y:
+		for _, tag := range tags {
-		if _, ok := radius.properties[tag]; ok {
+			if radius.getRaw(tag) != nil {
-			radius.Set(tag, AutoSize())
+				radius.setRaw(tag, nil)
-			delete(radius.properties, tag)
+				result = append(result, tag)
+			}
+		}
 	}
 
-	case TopLeftX, TopLeftY, TopRightX, TopRightY, BottomLeftX, BottomLeftY, BottomRightX, BottomRightY:
-		delete(radius.properties, tag)
-
-	case TopLeft, TopRight, BottomLeft, BottomRight:
-		radius.delete([]string{tag, tag + "-x", tag + "-y"})
-
-	default:
-		ErrorLogF(`"%s" property is not compatible with the RadiusProperty`, tag)
-	}
-
-}
-
-func (radius *radiusPropertyData) Set(tag string, value any) bool {
-	if value == nil {
-		radius.Remove(tag)
-		return true
-	}
-
-	tag = radius.normalizeTag(tag)
 	switch tag {
 	case X:
-		if radius.setSizeProperty(tag, value) {
+		if result = setSizeProperty(radius, tag, value); result != nil {
-			radius.delete([]string{TopLeftX, TopRightX, BottomLeftX, BottomRightX})
+			deleteTags([]PropertyName{TopLeftX, TopRightX, BottomLeftX, BottomRightX})
-			for _, t := range []string{TopLeft, TopRight, BottomLeft, BottomRight} {
+			for _, t := range []PropertyName{TopLeft, TopRight, BottomLeft, BottomRight} {
-				if val, ok := radius.properties[t]; ok {
+				if val := radius.getRaw(t); val != nil {
-					if _, ok := radius.properties[t+"-y"]; !ok {
+					t2 := t + "-y"
-						radius.properties[t+"-y"] = val
+					if radius.getRaw(t2) != nil {
+						radius.setRaw(t2, val)
+						result = append(result, t2)
 					}
-					delete(radius.properties, t)
+					radius.setRaw(t, nil)
+					result = append(result, t)
 				}
 			}
-			return true
 		}
 
 	case Y:
-		if radius.setSizeProperty(tag, value) {
+		if result = setSizeProperty(radius, tag, value); result != nil {
-			radius.delete([]string{TopLeftY, TopRightY, BottomLeftY, BottomRightY})
+			deleteTags([]PropertyName{TopLeftY, TopRightY, BottomLeftY, BottomRightY})
-			for _, t := range []string{TopLeft, TopRight, BottomLeft, BottomRight} {
+			for _, t := range []PropertyName{TopLeft, TopRight, BottomLeft, BottomRight} {
-				if val, ok := radius.properties[t]; ok {
+				if val := radius.getRaw(t); val != nil {
-					if _, ok := radius.properties[t+"-x"]; !ok {
+					t2 := t + "-x"
-						radius.properties[t+"-x"] = val
+					if radius.getRaw(t2) != nil {
+						radius.setRaw(t2, val)
+						result = append(result, t2)
 					}
-					delete(radius.properties, t)
+					radius.setRaw(t, nil)
+					result = append(result, t)
 				}
 			}
-			return true
 		}
 
 	case TopLeftX, TopLeftY, TopRightX, TopRightY, BottomLeftX, BottomLeftY, BottomRightX, BottomRightY:
-		if radius.setSizeProperty(tag, value) {
+		if result = setSizeProperty(radius, tag, value); result != nil {
-			radius.deleteUnusedTags()
+			deleteRadiusUnusedTags(radius, result)
-			return true
 		}
 
 	case TopLeft, TopRight, BottomLeft, BottomRight:
 		switch value := value.(type) {
 		case SizeUnit:
-			radius.properties[tag] = value
+			radius.setRaw(tag, value)
-			radius.delete([]string{tag + "-x", tag + "-y"})
+			result = []PropertyName{tag}
-			radius.deleteUnusedTags()
+			deleteTags([]PropertyName{tag + "-x", tag + "-y"})
-			return true
+			deleteRadiusUnusedTags(radius, result)
 
 		case string:
 			if strings.Contains(value, "/") {
 				if values := strings.Split(value, "/"); len(values) == 2 {
-					xOK := radius.Set(tag+"-x", value[0])
+					if result = radiusPropertySet(radius, tag+"-x", value[0]); result != nil {
-					yOK := radius.Set(tag+"-y", value[1])
+						if resultY := radiusPropertySet(radius, tag+"-y", value[1]); resultY != nil {
-					return xOK && yOK
+							result = append(result, resultY...)
+						}
+
+					}
 				} else {
 					notCompatibleType(tag, value)
 				}
 			} else {
-				if radius.setSizeProperty(tag, value) {
+				if result = setSizeProperty(radius, tag, value); result != nil {
-					radius.delete([]string{tag + "-x", tag + "-y"})
+					deleteTags([]PropertyName{tag + "-x", tag + "-y"})
-					radius.deleteUnusedTags()
+					deleteRadiusUnusedTags(radius, result)
-					return true
 				}
 			}
 		}
@@ -611,33 +645,32 @@ func (radius *radiusPropertyData) Set(tag string, value any) bool {
 		ErrorLogF(`"%s" property is not compatible with the RadiusProperty`, tag)
 	}
 
-	return false
+	return result
 }
 
-func (radius *radiusPropertyData) Get(tag string) any {
+func radiusPropertyGet(properties Properties, tag PropertyName) any {
-	tag = radius.normalizeTag(tag)
+	if value := properties.getRaw(tag); value != nil {
-	if value, ok := radius.properties[tag]; ok {
 		return value
 	}
 
 	switch tag {
 	case TopLeftX, TopLeftY, TopRightX, TopRightY, BottomLeftX, BottomLeftY, BottomRightX, BottomRightY:
 		tagLen := len(tag)
-		if value, ok := radius.properties[tag[:tagLen-2]]; ok {
+		if value := properties.getRaw(tag[:tagLen-2]); value != nil {
 			return value
 		}
-		if value, ok := radius.properties[tag[tagLen-1:]]; ok {
+		if value := properties.getRaw(tag[tagLen-1:]); value != nil {
 			return value
 		}
 	}
 
 	switch tag {
 	case TopLeftX, TopRightX, BottomLeftX, BottomRightX:
-		if value, ok := radius.properties[X]; ok {
+		if value := properties.getRaw(X); value != nil {
 			return value
 		}
 	case TopLeftY, TopRightY, BottomLeftY, BottomRightY:
-		if value, ok := radius.properties[Y]; ok {
+		if value := properties.getRaw(Y); value != nil {
 			return value
 		}
 	}
@@ -649,7 +682,7 @@ func (radius *radiusPropertyData) BoxRadius(session Session) BoxRadius {
 	x, _ := sizeProperty(radius, X, session)
 	y, _ := sizeProperty(radius, Y, session)
 
-	getRadius := func(tag string) (SizeUnit, SizeUnit) {
+	getRadius := func(tag PropertyName) (SizeUnit, SizeUnit) {
 		rx := x
 		ry := y
 		if r, ok := sizeProperty(radius, tag, session); ok {
@@ -866,21 +899,18 @@ func getRadiusProperty(style Properties) RadiusProperty {
 	return NewRadiusProperty(nil)
 }
 
-func (properties *propertyList) setRadius(value any) bool {
+func setRadiusProperty(properties Properties, value any) []PropertyName {
 
 	if value == nil {
-		delete(properties.properties, Radius)
+		return propertiesRemove(properties, Radius)
-		return true
 	}
 
 	switch value := value.(type) {
 	case RadiusProperty:
-		properties.properties[Radius] = value
+		properties.setRaw(Radius, value)
-		return true
 
 	case SizeUnit:
-		properties.properties[Radius] = value
+		properties.setRaw(Radius, value)
-		return true
 
 	case BoxRadius:
 		radius := NewRadiusProperty(nil)
@@ -913,78 +943,85 @@ func (properties *propertyList) setRadius(value any) bool {
 				radius.Set(BottomRightY, value.BottomRightY)
 			}
 		}
-		properties.properties[Radius] = radius
+		properties.setRaw(Radius, radius)
-		return true
 
 	case string:
 		if strings.Contains(value, "/") {
 			values := strings.Split(value, "/")
 			if len(values) == 2 {
-				okX := properties.setRadiusElement(RadiusX, values[0])
+				if setRadiusPropertyElement(properties, RadiusX, values[0]) {
-				okY := properties.setRadiusElement(RadiusY, values[1])
+					result := []PropertyName{Radius, RadiusX}
-				return okX && okY
+					if setRadiusPropertyElement(properties, RadiusY, values[1]) {
-			} else {
+						result = append(result, RadiusY)
-				notCompatibleType(Radius, value)
 					}
+					return result
+				}
+			}
+			notCompatibleType(Radius, value)
+			return nil
+
 		} else {
-			return properties.setSizeProperty(Radius, value)
+			return setSizeProperty(properties, Radius, value)
 		}
 
 	case DataObject:
 		radius := NewRadiusProperty(nil)
-		for _, tag := range []string{X, Y, TopLeft, TopRight, BottomLeft, BottomRight, TopLeftX, TopLeftY,
+		for _, tag := range []PropertyName{X, Y, TopLeft, TopRight, BottomLeft, BottomRight, TopLeftX, TopLeftY,
 			TopRightX, TopRightY, BottomLeftX, BottomLeftY, BottomRightX, BottomRightY} {
-			if value, ok := value.PropertyValue(tag); ok {
+			if value, ok := value.PropertyValue(string(tag)); ok {
 				radius.Set(tag, value)
 			}
 		}
-		properties.properties[Radius] = radius
+		properties.setRaw(Radius, radius)
-		return true
 
 	case float32:
-		return properties.setRadius(Px(float64(value)))
+		properties.setRaw(Radius, Px(float64(value)))
 
 	case float64:
-		return properties.setRadius(Px(value))
+		properties.setRaw(Radius, Px(value))
 
 	default:
 		if n, ok := isInt(value); ok {
-			return properties.setRadius(Px(float64(n)))
+			properties.setRaw(Radius, Px(float64(n)))
-		}
+		} else {
 			notCompatibleType(Radius, value)
+			return nil
+		}
 	}
 
+	return []PropertyName{Radius}
+}
+
+func removeRadiusPropertyElement(properties Properties, tag PropertyName) bool {
+	if value := properties.getRaw(Radius); value != nil {
+		radius := getRadiusProperty(properties)
+		radius.Remove(tag)
+		if radius.empty() {
+			properties.setRaw(Radius, nil)
+		} else {
+			properties.setRaw(Radius, radius)
+		}
+		return true
+	}
 	return false
 }
 
-func (properties *propertyList) removeRadiusElement(tag string) {
+func setRadiusPropertyElement(properties Properties, tag PropertyName, value any) bool {
-	if value, ok := properties.properties[Radius]; ok && value != nil {
-		radius := getRadiusProperty(properties)
-		radius.Remove(tag)
-		if len(radius.AllTags()) == 0 {
-			delete(properties.properties, Radius)
-		} else {
-			properties.properties[Radius] = radius
-		}
-	}
-}
-
-func (properties *propertyList) setRadiusElement(tag string, value any) bool {
 	if value == nil {
-		properties.removeRadiusElement(tag)
+		removeRadiusPropertyElement(properties, tag)
 		return true
 	}
 
 	radius := getRadiusProperty(properties)
 	if radius.Set(tag, value) {
-		properties.properties[Radius] = radius
+		properties.setRaw(Radius, radius)
 		return true
 	}
 
 	return false
 }
 
-func getRadiusElement(style Properties, tag string) any {
+func getRadiusElement(style Properties, tag PropertyName) any {
 	value := style.Get(Radius)
 	if value != nil {
 		switch value := value.(type) {

range.go

@@ -0,0 +1,75 @@
+package rui
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// Range defines range limits. The First and Last value are included in the range
+type Range struct {
+	First, Last int
+}
+
+// String returns a string representation of the Range struct
+func (r Range) String() string {
+	if r.First == r.Last {
+		return fmt.Sprintf("%d", r.First)
+	}
+	return fmt.Sprintf("%d:%d", r.First, r.Last)
+}
+
+func (r *Range) setValue(value string) bool {
+	var err error
+	if strings.Contains(value, ":") {
+		values := strings.Split(value, ":")
+		if len(values) != 2 {
+			ErrorLog("Invalid range value: " + value)
+			return false
+		}
+		if r.First, err = strconv.Atoi(strings.Trim(values[0], " \t\n\r")); err != nil {
+			ErrorLog(`Invalid first range value "` + value + `" (` + err.Error() + ")")
+			return false
+		}
+		if r.Last, err = strconv.Atoi(strings.Trim(values[1], " \t\n\r")); err != nil {
+			ErrorLog(`Invalid last range value "` + value + `" (` + err.Error() + ")")
+			return false
+		}
+		return true
+	}
+
+	if r.First, err = strconv.Atoi(value); err != nil {
+		ErrorLog(`Invalid range value "` + value + `" (` + err.Error() + ")")
+		return false
+	}
+	r.Last = r.First
+	return true
+}
+
+func setRangeProperty(properties Properties, tag PropertyName, value any) []PropertyName {
+	switch value := value.(type) {
+	case string:
+		if setSimpleProperty(properties, tag, value) {
+			return []PropertyName{tag}
+		}
+
+		var r Range
+		if !r.setValue(value) {
+			invalidPropertyValue(tag, value)
+			return nil
+		}
+		properties.setRaw(tag, r)
+
+	case Range:
+		properties.setRaw(tag, value)
+
+	default:
+		if n, ok := isInt(value); ok {
+			properties.setRaw(tag, Range{First: n, Last: n})
+		} else {
+			notCompatibleType(tag, value)
+			return nil
+		}
+	}
+	return []PropertyName{tag}
+}

resizable.go

@@ -62,7 +62,6 @@ type Resizable interface {
 
 type resizableData struct {
 	viewData
-	content []View
 }
 
 // NewResizable create new Resizable object and return it
@@ -74,147 +73,99 @@ func NewResizable(session Session, params Params) Resizable {
 }
 
 func newResizable(session Session) View {
-	return NewResizable(session, nil)
+	return new(resizableData)
 }
 
 func (resizable *resizableData) init(session Session) {
 	resizable.viewData.init(session)
 	resizable.tag = "Resizable"
 	resizable.systemClass = "ruiGridLayout"
-	resizable.content = []View{}
+	resizable.set = resizableSet
-}
+	resizable.changed = resizablePropertyChanged
-
-func (resizable *resizableData) String() string {
-	return getViewString(resizable, nil)
 }
 
 func (resizable *resizableData) Views() []View {
-	return resizable.content
+	if view := resizable.content(); view != nil {
+		return []View{view}
+	}
+	return []View{}
 }
 
-func (resizable *resizableData) Remove(tag string) {
+func (resizable *resizableData) content() View {
-	resizable.remove(strings.ToLower(tag))
+	if value := resizable.getRaw(Content); value != nil {
+		if content, ok := value.(View); ok {
+			return content
+		}
+	}
+	return nil
 }
 
-func (resizable *resizableData) remove(tag string) {
+func resizableSet(view View, tag PropertyName, value any) []PropertyName {
 	switch tag {
 	case Side:
-		oldSide := resizable.getSide()
+		return resizableSetSide(view, value)
-		delete(resizable.properties, Side)
-		if oldSide != resizable.getSide() {
-			if resizable.created {
-				updateInnerHTML(resizable.htmlID(), resizable.Session())
-				resizable.updateResizeBorderWidth()
-			}
-			resizable.propertyChangedEvent(tag)
-		}
 
 	case ResizeBorderWidth:
-		w := resizable.resizeBorderWidth()
+		return setSizeProperty(view, tag, value)
-		delete(resizable.properties, ResizeBorderWidth)
-		if !w.Equal(resizable.resizeBorderWidth()) {
-			resizable.updateResizeBorderWidth()
-			resizable.propertyChangedEvent(tag)
-		}
-
-	case Content:
-		if len(resizable.content) > 0 {
-			resizable.content = []View{}
-			if resizable.created {
-				updateInnerHTML(resizable.htmlID(), resizable.Session())
-			}
-			resizable.propertyChangedEvent(tag)
-		}
-
-	default:
-		resizable.viewData.remove(tag)
-	}
-}
-
-func (resizable *resizableData) Set(tag string, value any) bool {
-	return resizable.set(strings.ToLower(tag), value)
-}
-
-func (resizable *resizableData) set(tag string, value any) bool {
-	if value == nil {
-		resizable.remove(tag)
-		return true
-	}
-
-	switch tag {
-	case Side:
-		oldSide := resizable.getSide()
-		if !resizable.setSide(value) {
-			notCompatibleType(tag, value)
-			return false
-		}
-		if oldSide != resizable.getSide() {
-			if resizable.created {
-				updateInnerHTML(resizable.htmlID(), resizable.Session())
-				resizable.updateResizeBorderWidth()
-			}
-			resizable.propertyChangedEvent(tag)
-		}
-		return true
-
-	case ResizeBorderWidth:
-		w := resizable.resizeBorderWidth()
-		ok := resizable.setSizeProperty(tag, value)
-		if ok && !w.Equal(resizable.resizeBorderWidth()) {
-			resizable.updateResizeBorderWidth()
-			resizable.propertyChangedEvent(tag)
-		}
-		return ok
 
 	case Content:
 		var newContent View = nil
 		switch value := value.(type) {
 		case string:
-			newContent = NewTextView(resizable.Session(), Params{Text: value})
+			newContent = NewTextView(view.Session(), Params{Text: value})
 
 		case View:
 			newContent = value
 
 		case DataObject:
-			if view := CreateViewFromObject(resizable.Session(), value); view != nil {
+			if newContent = CreateViewFromObject(view.Session(), value); newContent == nil {
-				newContent = view
+				return nil
-			} else {
-				return false
 			}
 
 		default:
 			notCompatibleType(tag, value)
-			return false
+			return nil
 		}
 
-		if len(resizable.content) == 0 {
+		view.setRaw(Content, newContent)
-			resizable.content = []View{newContent}
+		return []PropertyName{}
-		} else {
-			resizable.content[0] = newContent
-		}
-		if resizable.created {
-			updateInnerHTML(resizable.htmlID(), resizable.Session())
-		}
-		resizable.propertyChangedEvent(tag)
-		return true
 
 	case CellWidth, CellHeight, GridRowGap, GridColumnGap, CellVerticalAlign, CellHorizontalAlign:
-		ErrorLogF(`Not supported "%s" property`, tag)
+		ErrorLogF(`Not supported "%s" property`, string(tag))
-		return false
+		return nil
 	}
 
-	return resizable.viewData.set(tag, value)
+	return viewSet(view, tag, value)
 }
 
-func (resizable *resizableData) Get(tag string) any {
+func resizablePropertyChanged(view View, tag PropertyName) {
-	return resizable.get(strings.ToLower(tag))
+	switch tag {
+	case Side:
+		updateInnerHTML(view.htmlID(), view.Session())
+		fallthrough
+
+	case ResizeBorderWidth:
+		htmlID := view.htmlID()
+		session := view.Session()
+		column, row := resizableCellSizeCSS(view)
+
+		session.updateCSSProperty(htmlID, "grid-template-columns", column)
+		session.updateCSSProperty(htmlID, "grid-template-rows", row)
+
+	case Content:
+		updateInnerHTML(view.htmlID(), view.Session())
+
+	default:
+		viewPropertyChanged(view, tag)
 	}
 
-func (resizable *resizableData) getSide() int {
+}
-	if value := resizable.getRaw(Side); value != nil {
+
+func resizableSide(view View) int {
+	if value := view.getRaw(Side); value != nil {
 		switch value := value.(type) {
 		case string:
-			if value, ok := resizable.session.resolveConstants(value); ok {
+			if value, ok := view.Session().resolveConstants(value); ok {
 				validValues := map[string]int{
 					"top":    TopSide,
 					"right":  RightSide,
@@ -258,15 +209,15 @@ func (resizable *resizableData) getSide() int {
 	return AllSides
 }
 
-func (resizable *resizableData) setSide(value any) bool {
+func resizableSetSide(properties Properties, value any) []PropertyName {
 	switch value := value.(type) {
 	case string:
 		if n, err := strconv.Atoi(value); err == nil {
 			if n >= 1 && n <= AllSides {
-				resizable.properties[Side] = n
+				properties.setRaw(Side, n)
-				return true
+				return []PropertyName{Side}
 			}
-			return false
+			return nil
 		}
 		validValues := map[string]int{
 			"top":    TopSide,
@@ -287,13 +238,13 @@ func (resizable *resizableData) setSide(value any) bool {
 					hasConst = true
 				} else if n, err := strconv.Atoi(val); err == nil {
 					if n < 1 || n > AllSides {
-						return false
+						return nil
 					}
 					sides |= n
 				} else if n, ok := validValues[val]; ok {
 					sides |= n
 				} else {
-					return false
+					return nil
 				}
 			}
 
@@ -302,69 +253,58 @@ func (resizable *resizableData) setSide(value any) bool {
 				for i := 1; i < len(values); i++ {
 					value += "|" + values[i]
 				}
-				resizable.properties[Side] = value
+				properties.setRaw(Side, value)
-				return true
+				return []PropertyName{Side}
 			}
 
 			if sides >= 1 && sides <= AllSides {
-				resizable.properties[Side] = sides
+				properties.setRaw(Side, sides)
-				return true
+				return []PropertyName{Side}
 			}
 
 		} else if value[0] == '@' {
-			resizable.properties[Side] = value
+			properties.setRaw(Side, value)
-			return true
+			return []PropertyName{Side}
 		} else if n, ok := validValues[value]; ok {
-			resizable.properties[Side] = n
+			properties.setRaw(Side, n)
-			return true
+			return []PropertyName{Side}
 		}
 
 	case int:
 		if value >= 1 && value <= AllSides {
-			resizable.properties[Side] = value
+			properties.setRaw(Side, value)
-			return true
+			return []PropertyName{Side}
 		} else {
 			ErrorLogF(`Invalid value %d of "side" property`, value)
-			return false
+			return nil
 		}
 
 	default:
 		if n, ok := isInt(value); ok {
 			if n >= 1 && n <= AllSides {
-				resizable.properties[Side] = n
+				properties.setRaw(Side, n)
-				return true
+				return []PropertyName{Side}
 			} else {
 				ErrorLogF(`Invalid value %d of "side" property`, n)
-				return false
+				return nil
 			}
 		}
 	}
 
-	return false
+	return nil
 }
 
-func (resizable *resizableData) resizeBorderWidth() SizeUnit {
+func resizableBorderWidth(view View) SizeUnit {
-	result, _ := sizeProperty(resizable, ResizeBorderWidth, resizable.Session())
+	result, _ := sizeProperty(view, ResizeBorderWidth, view.Session())
 	if result.Type == Auto || result.Value == 0 {
 		return Px(4)
 	}
 	return result
 }
 
-func (resizable *resizableData) updateResizeBorderWidth() {
+func resizableCellSizeCSS(view View) (string, string) {
-	if resizable.created {
+	w := resizableBorderWidth(view).cssString("4px", view.Session())
-		htmlID := resizable.htmlID()
+	side := resizableSide(view)
-		session := resizable.Session()
-		column, row := resizable.cellSizeCSS()
-
-		session.updateCSSProperty(htmlID, "grid-template-columns", column)
-		session.updateCSSProperty(htmlID, "grid-template-rows", row)
-	}
-}
-
-func (resizable *resizableData) cellSizeCSS() (string, string) {
-	w := resizable.resizeBorderWidth().cssString("4px", resizable.Session())
-	side := resizable.getSide()
 	column := "1fr"
 	row := "1fr"
 
@@ -392,7 +332,7 @@ func (resizable *resizableData) cellSizeCSS() (string, string) {
 }
 
 func (resizable *resizableData) cssStyle(self View, builder cssBuilder) {
-	column, row := resizable.cellSizeCSS()
+	column, row := resizableCellSizeCSS(resizable)
 
 	builder.add("grid-template-columns", column)
 	builder.add("grid-template-rows", row)
@@ -402,12 +342,12 @@ func (resizable *resizableData) cssStyle(self View, builder cssBuilder) {
 
 func (resizable *resizableData) htmlSubviews(self View, buffer *strings.Builder) {
 
-	side := resizable.getSide()
+	side := resizableSide(resizable)
 	left := 1
 	top := 1
 	leftSide := (side & LeftSide) != 0
 	rightSide := (side & RightSide) != 0
-	w := resizable.resizeBorderWidth().cssString("4px", resizable.Session())
+	w := resizableBorderWidth(resizable).cssString("4px", resizable.Session())
 
 	if leftSide {
 		left = 2
@@ -484,8 +424,7 @@ func (resizable *resizableData) htmlSubviews(self View, buffer *strings.Builder)
 		}
 	}
 
-	if len(resizable.content) > 0 {
+	if view := resizable.content(); view != nil {
-		view := resizable.content[0]
 		view.addToCSSStyle(map[string]string{
 			"grid-column-start": strconv.Itoa(left),
 			"grid-column-end":   strconv.Itoa(left + 1),

resizeEvent.go

@@ -16,7 +16,7 @@ package rui
 // `func(frame rui.Frame)`,
 // `func(view rui.View)`,
 // `func()`.
-const ResizeEvent = "resize-event"
+const ResizeEvent PropertyName = "resize-event"
 
 func (view *viewData) onResize(self View, x, y, width, height float64) {
 	view.frame.Left = x
@@ -31,21 +31,20 @@ func (view *viewData) onResize(self View, x, y, width, height float64) {
 func (view *viewData) onItemResize(self View, index string, x, y, width, height float64) {
 }
 
-func (view *viewData) setFrameListener(tag string, value any) bool {
+/*
-	listeners, ok := valueToEventListeners[View, Frame](value)
+func setFrameListener(properties Properties, tag PropertyName, value any) bool {
-	if !ok {
+	if listeners, ok := valueToEventListeners[View, Frame](value); ok {
+		if len(listeners) == 0 {
+			properties.setRaw(tag, nil)
+		} else {
+			properties.setRaw(tag, listeners)
+		}
+		return true
+	}
 	notCompatibleType(tag, value)
 	return false
 }
-
+*/
-	if listeners == nil {
-		delete(view.properties, tag)
-	} else {
-		view.properties[tag] = listeners
-	}
-	view.propertyChangedEvent(tag)
-	return true
-}
 
 func (view *viewData) setNoResizeEvent() {
 	view.noResizeEvent = true

scrollEvent.go

@@ -16,7 +16,7 @@ package rui
 // `func(frame rui.Frame)`,
 // `func(view rui.View)`,
 // `func()`.
-const ScrollEvent = "scroll-event"
+const ScrollEvent PropertyName = "scroll-event"
 
 func (view *viewData) onScroll(self View, x, y, width, height float64) {
 	view.scroll.Left = x

session.go

@@ -89,11 +89,11 @@ type Session interface {
 	RootView() View
 	// Get returns a value of the view (with id defined by the first argument) property with name defined by the second argument.
 	// The type of return value depends on the property. If the property is not set then nil is returned.
-	Get(viewID, tag string) any
+	Get(viewID string, tag PropertyName) any
 	// Set sets the value (third argument) of the property (second argument) of the view with id defined by the first argument.
 	// Return "true" if the value has been set, in the opposite case "false" are returned and
 	// a description of the error is written to the log
-	Set(viewID, tag string, value any) bool
+	Set(viewID string, tag PropertyName, value any) bool
 
 	// DownloadFile downloads (saves) on the client side the file located at the specified path on the server.
 	DownloadFile(path string)
@@ -134,7 +134,7 @@ type Session interface {
 
 	viewByHTMLID(id string) View
 	nextViewID() string
-	styleProperty(styleTag, property string) any
+	styleProperty(styleTag string, propertyTag PropertyName) any
 
 	setBridge(events chan DataObject, bridge bridge)
 	writeInitScript(writer *strings.Builder)
@@ -270,7 +270,7 @@ func (session *sessionData) close() {
 	}
 }
 
-func (session *sessionData) styleProperty(styleTag, propertyTag string) any {
+func (session *sessionData) styleProperty(styleTag string, propertyTag PropertyName) any {
 	if style := session.getCurrentTheme().style(styleTag); style != nil {
 		return style.getRaw(propertyTag)
 	}
@@ -376,14 +376,14 @@ func (session *sessionData) setIgnoreViewUpdates(ignore bool) {
 	session.ignoreUpdates = ignore
 }
 
-func (session *sessionData) Get(viewID, tag string) any {
+func (session *sessionData) Get(viewID string, tag PropertyName) any {
 	if view := ViewByID(session.RootView(), viewID); view != nil {
 		return view.Get(tag)
 	}
 	return nil
 }
 
-func (session *sessionData) Set(viewID, tag string, value any) bool {
+func (session *sessionData) Set(viewID string, tag PropertyName, value any) bool {
 	if view := ViewByID(session.RootView(), viewID); view != nil {
 		return view.Set(tag, value)
 	}
@@ -785,10 +785,10 @@ func (session *sessionData) handleEvent(command string, data DataObject) {
 		if viewID, ok := data.PropertyValue("id"); ok {
 			if viewID != "body" {
 				if view := session.viewByHTMLID(viewID); view != nil {
-					view.handleCommand(view, command, data)
+					view.handleCommand(view, PropertyName(command), data)
 				}
 			}
-			if command == KeyDownEvent {
+			if command == string(KeyDownEvent) {
 				var event KeyEvent
 				event.init(data)
 				session.hotKey(event)

shadow.go

@@ -42,7 +42,7 @@ const (
 	//
 	// Internal type is `Color`, other types converted to it during assignment.
 	// See `Color` description for more details.
-	ColorTag = "color"
+	ColorTag PropertyName = "color"
 
 	// Inset is the constant for "inset" property tag.
 	//
@@ -55,7 +55,7 @@ const (
 	// Values:
 	// `true` or `1` or "true", "yes", "on", "1" - Drop shadow inside the frame(as if the content was depressed inside the box).
 	// `false` or `0` or "false", "no", "off", "0" - Shadow is assumed to be a drop shadow(as if the box were raised above the content).
-	Inset = "inset"
+	Inset PropertyName = "inset"
 
 	// XOffset is the constant for "x-offset" property tag.
 	//
@@ -66,7 +66,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	XOffset = "x-offset"
+	XOffset PropertyName = "x-offset"
 
 	// YOffset is the constant for "y-offset" property tag.
 	//
@@ -77,7 +77,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	YOffset = "y-offset"
+	YOffset PropertyName = "y-offset"
 
 	// BlurRadius is the constant for "blur" property tag.
 	//
@@ -89,7 +89,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	BlurRadius = "blur"
+	BlurRadius PropertyName = "blur"
 
 	// SpreadRadius is the constant for "spread-radius" property tag.
 	//
@@ -100,7 +100,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	SpreadRadius = "spread-radius"
+	SpreadRadius PropertyName = "spread-radius"
 )
 
 // ViewShadow contains attributes of the view shadow
@@ -114,7 +114,7 @@ type ViewShadow interface {
 }
 
 type viewShadowData struct {
-	propertyList
+	dataProperty
 }
 
 // NewViewShadow create the new shadow for a view. Arguments:
@@ -188,11 +188,12 @@ func NewTextShadow(offsetX, offsetY, blurRadius SizeUnit, color Color) ViewShado
 // "inset" (Inset). Controls (bool) whether to draw shadow inside the frame or outside.
 func NewShadowWithParams(params Params) ViewShadow {
 	shadow := new(viewShadowData)
-	shadow.propertyList.init()
+	shadow.init()
+
 	if params != nil {
-		for _, tag := range []string{ColorTag, Inset, XOffset, YOffset, BlurRadius, SpreadRadius} {
+		for _, tag := range []PropertyName{ColorTag, Inset, XOffset, YOffset, BlurRadius, SpreadRadius} {
 			if value, ok := params[tag]; ok && value != nil {
-				shadow.Set(tag, value)
+				shadow.set(shadow, tag, value)
 			}
 		}
 	}
@@ -202,33 +203,14 @@ func NewShadowWithParams(params Params) ViewShadow {
 // parseViewShadow parse DataObject and create ViewShadow object
 func parseViewShadow(object DataObject) ViewShadow {
 	shadow := new(viewShadowData)
-	shadow.propertyList.init()
+	shadow.init()
 	parseProperties(shadow, object)
 	return shadow
 }
 
-func (shadow *viewShadowData) Remove(tag string) {
+func (shadow *viewShadowData) init() {
-	delete(shadow.properties, strings.ToLower(tag))
+	shadow.dataProperty.init()
-}
+	shadow.supportedProperties = []PropertyName{ColorTag, Inset, XOffset, YOffset, BlurRadius, SpreadRadius}
-
-func (shadow *viewShadowData) Set(tag string, value any) bool {
-	if value == nil {
-		shadow.Remove(tag)
-		return true
-	}
-
-	tag = strings.ToLower(tag)
-	switch tag {
-	case ColorTag, Inset, XOffset, YOffset, BlurRadius, SpreadRadius:
-		return shadow.propertyList.Set(tag, value)
-	}
-
-	ErrorLogF(`"%s" property is not supported by Shadow`, tag)
-	return false
-}
-
-func (shadow *viewShadowData) Get(tag string) any {
-	return shadow.propertyList.Get(strings.ToLower(tag))
 }
 
 func (shadow *viewShadowData) cssStyle(buffer *strings.Builder, session Session, lead string) bool {
@@ -316,7 +298,7 @@ func (shadow *viewShadowData) writeString(buffer *strings.Builder, indent string
 			if comma {
 				buffer.WriteString(", ")
 			}
-			buffer.WriteString(tag)
+			buffer.WriteString(string(tag))
 			buffer.WriteString(" = ")
 			writePropertyValue(buffer, tag, value, indent)
 			comma = true
@@ -325,29 +307,29 @@ func (shadow *viewShadowData) writeString(buffer *strings.Builder, indent string
 	buffer.WriteString(" }")
 }
 
-func (properties *propertyList) setShadow(tag string, value any) bool {
+func setShadowProperty(properties Properties, tag PropertyName, value any) bool {
 
 	if value == nil {
-		delete(properties.properties, tag)
+		properties.setRaw(tag, nil)
 		return true
 	}
 
 	switch value := value.(type) {
 	case ViewShadow:
-		properties.properties[tag] = []ViewShadow{value}
+		properties.setRaw(tag, []ViewShadow{value})
 
 	case []ViewShadow:
 		if len(value) == 0 {
-			delete(properties.properties, tag)
+			properties.setRaw(tag, nil)
 		} else {
-			properties.properties[tag] = value
+			properties.setRaw(tag, value)
 		}
 
 	case DataValue:
 		if !value.IsObject() {
 			return false
 		}
-		properties.properties[tag] = []ViewShadow{parseViewShadow(value.Object())}
+		properties.setRaw(tag, []ViewShadow{parseViewShadow(value.Object())})
 
 	case []DataValue:
 		shadows := []ViewShadow{}
@@ -359,7 +341,7 @@ func (properties *propertyList) setShadow(tag string, value any) bool {
 		if len(shadows) == 0 {
 			return false
 		}
-		properties.properties[tag] = shadows
+		properties.setRaw(tag, shadows)
 
 	case string:
 		obj := NewDataObject(value)
@@ -367,7 +349,7 @@ func (properties *propertyList) setShadow(tag string, value any) bool {
 			notCompatibleType(tag, value)
 			return false
 		}
-		properties.properties[tag] = []ViewShadow{parseViewShadow(obj)}
+		properties.setRaw(tag, []ViewShadow{parseViewShadow(obj)})
 
 	default:
 		notCompatibleType(tag, value)
@@ -377,7 +359,7 @@ func (properties *propertyList) setShadow(tag string, value any) bool {
 	return true
 }
 
-func getShadows(properties Properties, tag string) []ViewShadow {
+func getShadows(properties Properties, tag PropertyName) []ViewShadow {
 	if value := properties.Get(tag); value != nil {
 		switch value := value.(type) {
 		case []ViewShadow:
@@ -390,7 +372,7 @@ func getShadows(properties Properties, tag string) []ViewShadow {
 	return []ViewShadow{}
 }
 
-func shadowCSS(properties Properties, tag string, session Session) string {
+func shadowCSS(properties Properties, tag PropertyName, session Session) string {
 	shadows := getShadows(properties, tag)
 	if len(shadows) == 0 {
 		return ""

stackLayout.go

@@ -55,7 +55,7 @@ type StackLayout interface {
 
 type stackLayoutData struct {
 	viewsContainerData
-	peek              int
+	peek, prevPeek    int
 	pushView, popView View
 	animationType     int
 	onPushFinished    func()
@@ -71,7 +71,8 @@ func NewStackLayout(session Session, params Params) StackLayout {
 }
 
 func newStackLayout(session Session) View {
-	return NewStackLayout(session, nil)
+	//return NewStackLayout(session, nil)
+	return new(stackLayoutData)
 }
 
 // Init initialize fields of ViewsContainer by default values
@@ -80,10 +81,9 @@ func (layout *stackLayoutData) init(session Session) {
 	layout.tag = "StackLayout"
 	layout.systemClass = "ruiStackLayout"
 	layout.properties[TransitionEndEvent] = []func(View, string){layout.pushFinished, layout.popFinished}
-}
+	layout.getFunc = layout.get
-
+	layout.set = layout.setFunc
-func (layout *stackLayoutData) String() string {
+	layout.remove = layout.removeFunc
-	return getViewString(layout, nil)
 }
 
 func (layout *stackLayoutData) pushFinished(view View, tag string) {
@@ -97,7 +97,7 @@ func (layout *stackLayoutData) pushFinished(view View, tag string) {
 				layout.peek = 0
 			}
 			updateInnerHTML(layout.htmlID(), layout.session)
-			layout.propertyChangedEvent(Current)
+			layout.currentChanged()
 		}
 
 		if layout.onPushFinished != nil {
@@ -121,97 +121,91 @@ func (layout *stackLayoutData) popFinished(view View, tag string) {
 	}
 }
 
-func (layout *stackLayoutData) Set(tag string, value any) bool {
+func (layout *stackLayoutData) setFunc(view View, tag PropertyName, value any) []PropertyName {
-	return layout.set(strings.ToLower(tag), value)
-}
-
-func (layout *stackLayoutData) set(tag string, value any) bool {
-	if value == nil {
-		layout.remove(tag)
-		return true
-	}
-
 	switch tag {
 	case TransitionEndEvent:
 		listeners, ok := valueToEventListeners[View, string](value)
 		if ok && listeners != nil {
 			listeners = append(listeners, layout.pushFinished)
 			listeners = append(listeners, layout.popFinished)
-			layout.properties[TransitionEndEvent] = listeners
+			view.setRaw(TransitionEndEvent, listeners)
-			layout.propertyChangedEvent(TransitionEndEvent)
+			return []PropertyName{tag}
 		}
-		return ok
+		return nil
 
 	case Current:
-		setCurrent := func(index int) {
+		newCurrent := 0
-			if index != layout.peek {
-				if layout.peek < len(layout.views) {
-					layout.Session().updateCSSProperty(layout.htmlID()+"page"+strconv.Itoa(layout.peek), "visibility", "hidden")
-				}
-
-				layout.peek = index
-				layout.Session().updateCSSProperty(layout.htmlID()+"page"+strconv.Itoa(index), "visibility", "visible")
-				layout.propertyChangedEvent(Current)
-			}
-		}
 		switch value := value.(type) {
 		case string:
 			text, ok := layout.session.resolveConstants(value)
 			if !ok {
 				invalidPropertyValue(tag, value)
-				return false
+				return nil
 			}
 			n, err := strconv.Atoi(strings.Trim(text, " \t"))
 			if err != nil {
 				invalidPropertyValue(tag, value)
 				ErrorLog(err.Error())
-				return false
+				return nil
 			}
-			setCurrent(n)
+			newCurrent = n
 
 		default:
 			n, ok := isInt(value)
 			if !ok {
 				notCompatibleType(tag, value)
-				return false
+				return nil
 			} else if n < 0 || n >= len(layout.views) {
 				ErrorLogF(`The view index "%d" of "%s" property is out of range`, n, tag)
-				return false
+				return nil
 			}
-			setCurrent(n)
+			newCurrent = n
-		}
-		return true
-	}
-	return layout.viewsContainerData.set(tag, value)
 		}
 
-func (layout *stackLayoutData) Remove(tag string) {
+		layout.prevPeek = layout.peek
-	layout.remove(strings.ToLower(tag))
+		if newCurrent == layout.peek {
+			return []PropertyName{}
 		}
 
-func (layout *stackLayoutData) remove(tag string) {
+		layout.peek = newCurrent
+		return []PropertyName{tag}
+	}
+	return layout.viewsContainerData.setFunc(view, tag, value)
+}
+
+func (layout *stackLayoutData) propertyChanged(view View, tag PropertyName) {
+	switch tag {
+	case Current:
+		if layout.prevPeek != layout.peek {
+			if layout.prevPeek < len(layout.views) {
+				layout.Session().updateCSSProperty(layout.htmlID()+"page"+strconv.Itoa(layout.prevPeek), "visibility", "hidden")
+			}
+			layout.Session().updateCSSProperty(layout.htmlID()+"page"+strconv.Itoa(layout.prevPeek), "visibility", "visible")
+			layout.prevPeek = layout.peek
+		}
+	default:
+		viewsContainerPropertyChanged(view, tag)
+	}
+}
+
+func (layout *stackLayoutData) removeFunc(view View, tag PropertyName) []PropertyName {
 	switch tag {
 	case TransitionEndEvent:
-		layout.properties[TransitionEndEvent] = []func(View, string){layout.pushFinished, layout.popFinished}
+		view.setRaw(TransitionEndEvent, []func(View, string){layout.pushFinished, layout.popFinished})
-		layout.propertyChangedEvent(TransitionEndEvent)
+		return []PropertyName{tag}
 
 	case Current:
-		layout.set(Current, 0)
+		view.setRaw(Current, 0)
-
+		return []PropertyName{tag}
-	default:
-		layout.viewsContainerData.remove(tag)
 	}
+	return layout.viewsContainerData.removeFunc(view, tag)
 }
 
-func (layout *stackLayoutData) Get(tag string) any {
+func (layout *stackLayoutData) get(view View, tag PropertyName) any {
-	return layout.get(strings.ToLower(tag))
-}
-
-func (layout *stackLayoutData) get(tag string) any {
 	if tag == Current {
 		return layout.peek
 	}
-	return layout.viewsContainerData.get(tag)
+	return layout.viewsContainerData.get(view, tag)
 }
 
 func (layout *stackLayoutData) Peek() View {
@@ -233,7 +227,7 @@ func (layout *stackLayoutData) MoveToFront(view View) bool {
 
 				layout.peek = i
 				layout.Session().updateCSSProperty(layout.htmlID()+"page"+strconv.Itoa(i), "visibility", "visible")
-				layout.propertyChangedEvent(Current)
+				layout.currentChanged()
 			}
 			return true
 		}
@@ -243,6 +237,12 @@ func (layout *stackLayoutData) MoveToFront(view View) bool {
 	return false
 }
 
+func (layout *stackLayoutData) currentChanged() {
+	if listener, ok := layout.changeListener[Current]; ok {
+		listener(layout, Current)
+	}
+}
+
 func (layout *stackLayoutData) MoveToFrontByID(viewID string) bool {
 	peek := int(layout.peek)
 	for i, view := range layout.views {
@@ -254,7 +254,7 @@ func (layout *stackLayoutData) MoveToFrontByID(viewID string) bool {
 
 				layout.peek = i
 				layout.Session().updateCSSProperty(layout.htmlID()+"page"+strconv.Itoa(i), "visibility", "visible")
-				layout.propertyChangedEvent(Current)
+				layout.currentChanged()
 			}
 			return true
 		}
@@ -268,7 +268,7 @@ func (layout *stackLayoutData) Append(view View) {
 	if view != nil {
 		layout.peek = len(layout.views)
 		layout.viewsContainerData.Append(view)
-		layout.propertyChangedEvent(Current)
+		layout.currentChanged()
 	} else {
 		ErrorLog("StackLayout.Append(nil, ....) is forbidden")
 	}
@@ -283,7 +283,7 @@ func (layout *stackLayoutData) Insert(view View, index int) {
 			layout.peek = count
 		}
 		layout.viewsContainerData.Insert(view, index)
-		layout.propertyChangedEvent(Current)
+		layout.currentChanged()
 	} else {
 		ErrorLog("StackLayout.Insert(nil, ....) is forbidden")
 	}
@@ -297,7 +297,7 @@ func (layout *stackLayoutData) RemoveView(index int) View {
 	if layout.peek > 0 {
 		layout.peek--
 	}
-	defer layout.propertyChangedEvent(Current)
+	defer layout.currentChanged()
 	return layout.viewsContainerData.RemoveView(index)
 }
 
@@ -352,7 +352,10 @@ func (layout *stackLayoutData) Push(view View, animation int, onPushFinished fun
 
 	layout.views = append(layout.views, view)
 	view.setParentID(htmlID)
-	layout.propertyChangedEvent(Content)
+
+	if listener, ok := layout.changeListener[Content]; ok {
+		listener(layout, Content)
+	}
 }
 
 func (layout *stackLayoutData) Pop(animation int, onPopFinished func(View)) bool {

svgImageView.go

@@ -25,7 +25,7 @@ func NewSvgImageView(session Session, params Params) SvgImageView {
 }
 
 func newSvgImageView(session Session) View {
-	return NewSvgImageView(session, nil)
+	return new(svgImageViewData) // NewSvgImageView(session, nil)
 }
 
 // Init initialize fields of imageView by default values
@@ -33,14 +33,14 @@ func (imageView *svgImageViewData) init(session Session) {
 	imageView.viewData.init(session)
 	imageView.tag = "SvgImageView"
 	imageView.systemClass = "ruiSvgImageView"
+	imageView.normalize = normalizeSvgImageViewTag
+	imageView.set = svgImageViewSet
+	imageView.changed = svgImageViewPropertyChanged
+
 }
 
-func (imageView *svgImageViewData) String() string {
+func normalizeSvgImageViewTag(tag PropertyName) PropertyName {
-	return getViewString(imageView, nil)
+	tag = defaultNormalize(tag)
-}
-
-func (imageView *svgImageViewData) normalizeTag(tag string) string {
-	tag = strings.ToLower(tag)
 	switch tag {
 	case Source, "source":
 		tag = Content
@@ -54,51 +54,29 @@ func (imageView *svgImageViewData) normalizeTag(tag string) string {
 	return tag
 }
 
-func (imageView *svgImageViewData) Remove(tag string) {
+func svgImageViewSet(view View, tag PropertyName, value any) []PropertyName {
-	imageView.remove(imageView.normalizeTag(tag))
-}
-
-func (imageView *svgImageViewData) remove(tag string) {
-	imageView.viewData.remove(tag)
-
-	if imageView.created {
-		switch tag {
-		case Content:
-			updateInnerHTML(imageView.htmlID(), imageView.session)
-		}
-	}
-}
-
-func (imageView *svgImageViewData) Set(tag string, value any) bool {
-	return imageView.set(imageView.normalizeTag(tag), value)
-}
-
-func (imageView *svgImageViewData) set(tag string, value any) bool {
-	if value == nil {
-		imageView.remove(tag)
-		return true
-	}
-
 	switch tag {
 	case Content:
 		if text, ok := value.(string); ok {
-			imageView.properties[Content] = text
+			view.setRaw(Content, text)
-			if imageView.created {
+			return []PropertyName{tag}
-				updateInnerHTML(imageView.htmlID(), imageView.session)
-			}
-			imageView.propertyChangedEvent(Content)
-			return true
 		}
 		notCompatibleType(Source, value)
-		return false
+		return nil
 
 	default:
-		return imageView.viewData.set(tag, value)
+		return viewSet(view, tag, value)
 	}
 }
 
-func (imageView *svgImageViewData) Get(tag string) any {
+func svgImageViewPropertyChanged(view View, tag PropertyName) {
-	return imageView.viewData.get(imageView.normalizeTag(tag))
+	switch tag {
+	case Content:
+		updateInnerHTML(view.htmlID(), view.Session())
+
+	default:
+		viewPropertyChanged(view, tag)
+	}
 }
 
 func (imageView *svgImageViewData) htmlTag() string {

tableAdapter.go

@@ -256,78 +256,3 @@ func (style *simpleTableLineStyle) RowStyle(row int) Params {
 	}
 	return nil
 }
-
-func (table *tableViewData) setLineStyle(tag string, value any) bool {
-	switch value := value.(type) {
-	case []Params:
-		if len(value) > 0 {
-			style := new(simpleTableLineStyle)
-			style.params = value
-			table.properties[tag] = style
-		} else {
-			delete(table.properties, tag)
-		}
-
-	case DataNode:
-		if params := value.ArrayAsParams(); len(params) > 0 {
-			style := new(simpleTableLineStyle)
-			style.params = params
-			table.properties[tag] = style
-		} else {
-			delete(table.properties, tag)
-		}
-
-	default:
-		return false
-	}
-	return true
-}
-
-func (table *tableViewData) setRowStyle(value any) bool {
-	switch value := value.(type) {
-	case TableRowStyle:
-		table.properties[RowStyle] = value
-	}
-	return table.setLineStyle(RowStyle, value)
-}
-
-func (table *tableViewData) getRowStyle() TableRowStyle {
-	for _, tag := range []string{RowStyle, Content} {
-		if value := table.getRaw(tag); value != nil {
-			if style, ok := value.(TableRowStyle); ok {
-				return style
-			}
-		}
-	}
-	return nil
-}
-
-func (table *tableViewData) setColumnStyle(value any) bool {
-	switch value := value.(type) {
-	case TableColumnStyle:
-		table.properties[ColumnStyle] = value
-	}
-	return table.setLineStyle(ColumnStyle, value)
-}
-
-func (table *tableViewData) getColumnStyle() TableColumnStyle {
-	for _, tag := range []string{ColumnStyle, Content} {
-		if value := table.getRaw(tag); value != nil {
-			if style, ok := value.(TableColumnStyle); ok {
-				return style
-			}
-		}
-	}
-	return nil
-}
-
-func (table *tableViewData) getCellStyle() TableCellStyle {
-	for _, tag := range []string{CellStyle, Content} {
-		if value := table.getRaw(tag); value != nil {
-			if style, ok := value.(TableCellStyle); ok {
-				return style
-			}
-		}
-	}
-	return nil
-}

tableViewUtils.go

@@ -1,17 +1,19 @@
 package rui
 
-import "strings"
+func newTableCellView(session Session) *tableCellView {
-
+	view := new(tableCellView)
-func (cell *tableCellView) Set(tag string, value any) bool {
+	view.init(session)
-	return cell.set(strings.ToLower(tag), value)
+	return view
 }
 
-func (cell *tableCellView) set(tag string, value any) bool {
+func (cell *tableCellView) init(session Session) {
-	switch tag {
+	cell.viewData.init(session)
-	case VerticalAlign:
+	cell.normalize = func(tag PropertyName) PropertyName {
-		tag = TableVerticalAlign
+		if tag == VerticalAlign {
+			return TableVerticalAlign
+		}
+		return tag
 	}
-	return cell.viewData.set(tag, value)
 }
 
 func (cell *tableCellView) cssStyle(self View, builder cssBuilder) {
@@ -31,8 +33,10 @@ func GetTableContent(view View, subviewID ...string) TableAdapter {
 	}
 
 	if view != nil {
-		if tableView, ok := view.(TableView); ok {
+		if content := view.getRaw(Content); content != nil {
-			return tableView.content()
+			if adapter, ok := content.(TableAdapter); ok {
+				return adapter
+			}
 		}
 	}
 
@@ -47,8 +51,12 @@ func GetTableRowStyle(view View, subviewID ...string) TableRowStyle {
 	}
 
 	if view != nil {
-		if tableView, ok := view.(TableView); ok {
+		for _, tag := range []PropertyName{RowStyle, Content} {
-			return tableView.getRowStyle()
+			if value := view.getRaw(tag); value != nil {
+				if style, ok := value.(TableRowStyle); ok {
+					return style
+				}
+			}
 		}
 	}
 
@@ -63,8 +71,12 @@ func GetTableColumnStyle(view View, subviewID ...string) TableColumnStyle {
 	}
 
 	if view != nil {
-		if tableView, ok := view.(TableView); ok {
+		for _, tag := range []PropertyName{ColumnStyle, Content} {
-			return tableView.getColumnStyle()
+			if value := view.getRaw(tag); value != nil {
+				if style, ok := value.(TableColumnStyle); ok {
+					return style
+				}
+			}
 		}
 	}
 
@@ -79,10 +91,15 @@ func GetTableCellStyle(view View, subviewID ...string) TableCellStyle {
 	}
 
 	if view != nil {
-		if tableView, ok := view.(TableView); ok {
+		for _, tag := range []PropertyName{CellStyle, Content} {
-			return tableView.getCellStyle()
+			if value := view.getRaw(tag); value != nil {
+				if style, ok := value.(TableCellStyle); ok {
+					return style
 				}
 			}
+		}
+		return nil
+	}
 
 	return nil
 }
@@ -125,9 +142,7 @@ func GetTableCurrent(view View, subviewID ...string) CellIndex {
 
 	if view != nil {
 		if selectionMode := GetTableSelectionMode(view); selectionMode != NoneSelection {
-			if tableView, ok := view.(TableView); ok {
+			return tableViewCurrent(view)
-				return tableView.getCurrent()
-			}
 		}
 	}
 	return CellIndex{Row: -1, Column: -1}
@@ -137,34 +152,14 @@ func GetTableCurrent(view View, subviewID ...string) CellIndex {
 // If there are no listeners then the empty list is returned.
 // If the second argument (subviewID) is not specified or it is "" then a value from the first argument (view) is returned.
 func GetTableCellClickedListeners(view View, subviewID ...string) []func(TableView, int, int) {
-	if len(subviewID) > 0 && subviewID[0] != "" {
+	return getEventWithOldListeners[TableView, int](view, subviewID, TableCellClickedEvent)
-		view = ViewByID(view, subviewID[0])
-	}
-	if view != nil {
-		if value := view.Get(TableCellClickedEvent); value != nil {
-			if result, ok := value.([]func(TableView, int, int)); ok {
-				return result
-			}
-		}
-	}
-	return []func(TableView, int, int){}
 }
 
 // GetTableCellSelectedListeners returns listeners of event which occurs when a table cell becomes selected.
 // If there are no listeners then the empty list is returned.
 // If the second argument (subviewID) is not specified or it is "" then a value from the first argument (view) is returned.
 func GetTableCellSelectedListeners(view View, subviewID ...string) []func(TableView, int, int) {
-	if len(subviewID) > 0 && subviewID[0] != "" {
+	return getEventWithOldListeners[TableView, int](view, subviewID, TableCellSelectedEvent)
-		view = ViewByID(view, subviewID[0])
-	}
-	if view != nil {
-		if value := view.Get(TableCellSelectedEvent); value != nil {
-			if result, ok := value.([]func(TableView, int, int)); ok {
-				return result
-			}
-		}
-	}
-	return []func(TableView, int, int){}
 }
 
 // GetTableRowClickedListeners returns listeners of event which occurs when the user clicks on a table row.

tabsLayout.go

@@ -5,7 +5,7 @@ import (
 	"strings"
 )
 
-// Constants for [TabsLayout] specific properties and events
+// Constants for [TabsLayout] specific view and events
 const (
 	// CurrentTabChangedEvent is the constant for "current-tab-changed" property tag.
 	//
@@ -25,7 +25,7 @@ const (
 	// `func(newTab, oldTab int)`,
 	// `func(newTab int)`,
 	// `func()`.
-	CurrentTabChangedEvent = "current-tab-changed"
+	CurrentTabChangedEvent PropertyName = "current-tab-changed"
 
 	// Icon is the constant for "icon" property tag.
 	//
@@ -47,7 +47,7 @@ const (
 	// Values:
 	// `true` or `1` or "true", "yes", "on", "1" - Tab(s) has close button.
 	// `false` or `0` or "false", "no", "off", "0" - No close button in tab(s).
-	TabCloseButton = "tab-close-button"
+	TabCloseButton PropertyName = "tab-close-button"
 
 	// TabCloseEvent is the constant for "tab-close-event" property tag.
 	//
@@ -65,7 +65,7 @@ const (
 	// `func(tab int)`,
 	// `func(tabsLayout rui.TabsLayout)`,
 	// `func()`.
-	TabCloseEvent = "tab-close-event"
+	TabCloseEvent PropertyName = "tab-close-event"
 
 	// Tabs is the constant for "tabs" property tag.
 	//
@@ -82,7 +82,7 @@ const (
 	// `4`(`LeftListTabs`) or "left-list" - Tabs on the left. The tabs are displayed as a list.
 	// `5`(`RightListTabs`) or "right-list" - Tabs on the right. The tabs are displayed as a list.
 	// `6`(`HiddenTabs`) or "hidden" - Tabs are hidden.
-	Tabs = "tabs"
+	Tabs PropertyName = "tabs"
 
 	// TabBarStyle is the constant for "tab-bar-style" property tag.
 	//
@@ -90,7 +90,7 @@ const (
 	// Set the style for the display of the tab bar. The default value is "ruiTabBar".
 	//
 	// Supported types: `string`.
-	TabBarStyle = "tab-bar-style"
+	TabBarStyle PropertyName = "tab-bar-style"
 
 	// TabStyle is the constant for "tab-style" property tag.
 	//
@@ -98,7 +98,7 @@ const (
 	// Set the style for the display of the tab. The default value is "ruiTab" or "ruiVerticalTab".
 	//
 	// Supported types: `string`.
-	TabStyle = "tab-style"
+	TabStyle PropertyName = "tab-style"
 
 	// CurrentTabStyle is the constant for "current-tab-style" property tag.
 	//
@@ -107,7 +107,7 @@ const (
 	// "ruiCurrentVerticalTab".
 	//
 	// Supported types: `string`.
-	CurrentTabStyle = "current-tab-style"
+	CurrentTabStyle PropertyName = "current-tab-style"
 
 	inactiveTabStyle = "data-inactiveTabStyle"
 	activeTabStyle   = "data-activeTabStyle"
@@ -139,8 +139,6 @@ type TabsLayout interface {
 
 type tabsLayoutData struct {
 	viewsContainerData
-	tabListener      []func(TabsLayout, int, int)
-	tabCloseListener []func(TabsLayout, int)
 }
 
 // NewTabsLayout create new TabsLayout object and return it
@@ -152,7 +150,8 @@ func NewTabsLayout(session Session, params Params) TabsLayout {
 }
 
 func newTabsLayout(session Session) View {
-	return NewTabsLayout(session, nil)
+	//return NewTabsLayout(session, nil)
+	return new(tabsLayoutData)
 }
 
 // Init initialize fields of ViewsContainer by default values
@@ -160,199 +159,82 @@ func (tabsLayout *tabsLayoutData) init(session Session) {
 	tabsLayout.viewsContainerData.init(session)
 	tabsLayout.tag = "TabsLayout"
 	tabsLayout.systemClass = "ruiTabsLayout"
-	tabsLayout.tabListener = []func(TabsLayout, int, int){}
+	tabsLayout.set = tabsLayout.setFunc
-	tabsLayout.tabCloseListener = []func(TabsLayout, int){}
+	tabsLayout.changed = tabsLayout.propertyChanged
 }
 
-func (tabsLayout *tabsLayoutData) String() string {
+func tabsLayoutCurrent(view View, defaultValue int) int {
-	return getViewString(tabsLayout, nil)
+	result, _ := intProperty(view, Current, view.Session(), defaultValue)
-}
-
-func (tabsLayout *tabsLayoutData) currentItem(defaultValue int) int {
-	result, _ := intProperty(tabsLayout, Current, tabsLayout.session, defaultValue)
 	return result
 }
 
-func (tabsLayout *tabsLayoutData) Get(tag string) any {
+func (tabsLayout *tabsLayoutData) setFunc(view View, tag PropertyName, value any) []PropertyName {
-	return tabsLayout.get(strings.ToLower(tag))
-}
-
-func (tabsLayout *tabsLayoutData) get(tag string) any {
 	switch tag {
 	case CurrentTabChangedEvent:
-		return tabsLayout.tabListener
+		return setEventWithOldListener[TabsLayout, int](view, tag, value)
 
 	case TabCloseEvent:
-		return tabsLayout.tabCloseListener
+		return setViewEventListener[TabsLayout, int](view, tag, value)
-	}
-
-	return tabsLayout.viewsContainerData.get(tag)
-}
-
-func (tabsLayout *tabsLayoutData) Remove(tag string) {
-	tabsLayout.remove(strings.ToLower(tag))
-}
-
-func (tabsLayout *tabsLayoutData) remove(tag string) {
-	switch tag {
-	case CurrentTabChangedEvent:
-		if len(tabsLayout.tabListener) > 0 {
-			tabsLayout.tabListener = []func(TabsLayout, int, int){}
-			tabsLayout.propertyChangedEvent(tag)
-		}
-		return
-
-	case TabCloseEvent:
-		if len(tabsLayout.tabCloseListener) > 0 {
-			tabsLayout.tabCloseListener = []func(TabsLayout, int){}
-			tabsLayout.propertyChangedEvent(tag)
-		}
-		return
 
 	case Current:
-		oldCurrent := tabsLayout.currentItem(0)
+		view.setRaw("old-current", tabsLayoutCurrent(view, -1))
-		delete(tabsLayout.properties, Current)
-		if oldCurrent == 0 {
-			return
-		}
-		if tabsLayout.created {
-			tabsLayout.session.callFunc("activateTab", tabsLayout.htmlID(), 0)
-			for _, listener := range tabsLayout.tabListener {
-				listener(tabsLayout, 0, oldCurrent)
-			}
-		}
 
-	case Tabs:
-		delete(tabsLayout.properties, Tabs)
-		if tabsLayout.created {
-			htmlID := tabsLayout.htmlID()
-			tabsLayout.session.updateProperty(htmlID, inactiveTabStyle, tabsLayout.inactiveTabStyle())
-			tabsLayout.session.updateProperty(htmlID, activeTabStyle, tabsLayout.activeTabStyle())
-			updateCSSStyle(htmlID, tabsLayout.session)
-			updateInnerHTML(htmlID, tabsLayout.session)
-		}
-
-	case TabStyle, CurrentTabStyle:
-		delete(tabsLayout.properties, tag)
-		if tabsLayout.created {
-			htmlID := tabsLayout.htmlID()
-			tabsLayout.session.updateProperty(htmlID, inactiveTabStyle, tabsLayout.inactiveTabStyle())
-			tabsLayout.session.updateProperty(htmlID, activeTabStyle, tabsLayout.activeTabStyle())
-			updateInnerHTML(htmlID, tabsLayout.session)
-		}
-
-	case TabCloseButton:
-		delete(tabsLayout.properties, tag)
-		if tabsLayout.created {
-			updateInnerHTML(tabsLayout.htmlID(), tabsLayout.session)
-		}
-
-	default:
-		tabsLayout.viewsContainerData.remove(tag)
-		return
-	}
-
-	tabsLayout.propertyChangedEvent(tag)
-}
-
-func (tabsLayout *tabsLayoutData) Set(tag string, value any) bool {
-	return tabsLayout.set(strings.ToLower(tag), value)
-}
-
-func (tabsLayout *tabsLayoutData) set(tag string, value any) bool {
-	if value == nil {
-		tabsLayout.remove(tag)
-		return true
-	}
-
-	switch tag {
-	case CurrentTabChangedEvent:
-		listeners := tabsLayout.valueToTabListeners(value)
-		if listeners == nil {
-			notCompatibleType(tag, value)
-			return false
-		}
-		tabsLayout.tabListener = listeners
-
-	case TabCloseEvent:
-		listeners, ok := valueToEventListeners[TabsLayout, int](value)
-		if !ok {
-			notCompatibleType(tag, value)
-			return false
-		} else if listeners == nil {
-			listeners = []func(TabsLayout, int){}
-		}
-		tabsLayout.tabCloseListener = listeners
-
-	case Current:
 		if current, ok := value.(int); ok && current < 0 {
-			tabsLayout.remove(Current)
+			view.setRaw(Current, nil)
-			return true
+			return []PropertyName{tag}
 		}
 
-		oldCurrent := tabsLayout.currentItem(-1)
+		return setIntProperty(view, Current, value)
-		if !tabsLayout.setIntProperty(Current, value) {
+
-			return false
+	case TabStyle, CurrentTabStyle, TabBarStyle:
+		if text, ok := value.(string); ok {
+			return setStringPropertyValue(view, tag, text)
+		}
+		notCompatibleType(tag, value)
+		return nil
 	}
 
-		current := tabsLayout.currentItem(0)
+	return tabsLayout.viewsContainerData.setFunc(tabsLayout, tag, value)
-		if oldCurrent == current {
-			return true
 }
-		if tabsLayout.created {
+
-			tabsLayout.session.callFunc("activateTab", tabsLayout.htmlID(), current)
+func (tabsLayout *tabsLayoutData) propertyChanged(view View, tag PropertyName) {
-			for _, listener := range tabsLayout.tabListener {
+	switch tag {
+	case Current:
+		session := view.Session()
+		current := GetCurrent(view)
+		session.callFunc("activateTab", view.htmlID(), current)
+
+		if listeners := getEventWithOldListeners[TabsLayout, int](view, nil, CurrentTabChangedEvent); len(listeners) > 0 {
+			oldCurrent, _ := intProperty(view, "old-current", session, -1)
+			for _, listener := range listeners {
 				listener(tabsLayout, current, oldCurrent)
 			}
 		}
 
 	case Tabs:
-		if !tabsLayout.setEnumProperty(Tabs, value, enumProperties[Tabs].values) {
+		htmlID := view.htmlID()
-			return false
+		session := view.Session()
-		}
+		session.updateProperty(htmlID, inactiveTabStyle, tabsLayoutInactiveTabStyle(view))
-		if tabsLayout.created {
+		session.updateProperty(htmlID, activeTabStyle, tabsLayoutActiveTabStyle(view))
-			htmlID := tabsLayout.htmlID()
+		updateCSSStyle(htmlID, session)
-			tabsLayout.session.updateProperty(htmlID, inactiveTabStyle, tabsLayout.inactiveTabStyle())
+		updateInnerHTML(htmlID, session)
-			tabsLayout.session.updateProperty(htmlID, activeTabStyle, tabsLayout.activeTabStyle())
-			updateCSSStyle(htmlID, tabsLayout.session)
-			updateInnerHTML(htmlID, tabsLayout.session)
-		}
 
 	case TabStyle, CurrentTabStyle, TabBarStyle:
-		if text, ok := value.(string); ok {
+		htmlID := view.htmlID()
-			if text == "" {
+		session := view.Session()
-				delete(tabsLayout.properties, tag)
+		session.updateProperty(htmlID, inactiveTabStyle, tabsLayoutInactiveTabStyle(view))
-			} else {
+		session.updateProperty(htmlID, activeTabStyle, tabsLayoutActiveTabStyle(view))
-				tabsLayout.properties[tag] = text
+		updateInnerHTML(htmlID, session)
-			}
-		} else {
-			notCompatibleType(tag, value)
-			return false
-		}
-
-		if tabsLayout.created {
-			htmlID := tabsLayout.htmlID()
-			tabsLayout.session.updateProperty(htmlID, inactiveTabStyle, tabsLayout.inactiveTabStyle())
-			tabsLayout.session.updateProperty(htmlID, activeTabStyle, tabsLayout.activeTabStyle())
-			updateInnerHTML(htmlID, tabsLayout.session)
-		}
 
 	case TabCloseButton:
-		if !tabsLayout.setBoolProperty(tag, value) {
+		updateInnerHTML(view.htmlID(), view.Session())
-			return false
-		}
-		if tabsLayout.created {
-			updateInnerHTML(tabsLayout.htmlID(), tabsLayout.session)
-		}
 
 	default:
-		return tabsLayout.viewsContainerData.set(tag, value)
+		viewsContainerPropertyChanged(view, tag)
-	}
+	}
-
-	tabsLayout.propertyChangedEvent(tag)
-	return true
 }
 
+/*
 	func (tabsLayout *tabsLayoutData) valueToTabListeners(value any) []func(TabsLayout, int, int) {
 		if value == nil {
 			return []func(TabsLayout, int, int){}
@@ -499,6 +381,7 @@ func (tabsLayout *tabsLayoutData) valueToTabListeners(value any) []func(TabsLayo
 
 		return nil
 	}
+*/
 
 func (tabsLayout *tabsLayoutData) tabsLocation() int {
 	tabs, _ := enumProperty(tabsLayout, Tabs, tabsLayout.session, 0)
@@ -519,36 +402,42 @@ func (tabsLayout *tabsLayoutData) tabBarStyle() string {
 	return "ruiTabBar"
 }
 
-func (tabsLayout *tabsLayoutData) inactiveTabStyle() string {
+func tabsLayoutInactiveTabStyle(view View) string {
-	if style, ok := stringProperty(tabsLayout, TabStyle, tabsLayout.session); ok {
+	session := view.Session()
+	if style, ok := stringProperty(view, TabStyle, session); ok {
 		return style
 	}
-	if value := valueFromStyle(tabsLayout, TabStyle); value != nil {
+	if value := valueFromStyle(view, TabStyle); value != nil {
 		if style, ok := value.(string); ok {
-			if style, ok = tabsLayout.session.resolveConstants(style); ok {
+			if style, ok = session.resolveConstants(style); ok {
 				return style
 			}
 		}
 	}
-	switch tabsLayout.tabsLocation() {
+
+	tabs, _ := enumProperty(view, Tabs, session, 0)
+	switch tabs {
 	case LeftTabs, RightTabs:
 		return "ruiVerticalTab"
 	}
 	return "ruiTab"
 }
 
-func (tabsLayout *tabsLayoutData) activeTabStyle() string {
+func tabsLayoutActiveTabStyle(view View) string {
-	if style, ok := stringProperty(tabsLayout, CurrentTabStyle, tabsLayout.session); ok {
+	session := view.Session()
+	if style, ok := stringProperty(view, CurrentTabStyle, session); ok {
 		return style
 	}
-	if value := valueFromStyle(tabsLayout, CurrentTabStyle); value != nil {
+	if value := valueFromStyle(view, CurrentTabStyle); value != nil {
 		if style, ok := value.(string); ok {
-			if style, ok = tabsLayout.session.resolveConstants(style); ok {
+			if style, ok = session.resolveConstants(style); ok {
 				return style
 			}
 		}
 	}
-	switch tabsLayout.tabsLocation() {
+
+	tabs, _ := enumProperty(view, Tabs, session, 0)
+	switch tabs {
 	case LeftTabs, RightTabs:
 		return "ruiCurrentVerticalTab"
 	}
@@ -610,7 +499,7 @@ func (tabsLayout *tabsLayoutData) ListItem(index int, session Session) View {
 			Column:  2,
 			Content: "✕",
 			ClickEvent: func() {
-				for _, listener := range tabsLayout.tabCloseListener {
+				for _, listener := range getEventListeners[TabsLayout, int](tabsLayout, nil, TabCloseEvent) {
 					listener(tabsLayout, index)
 				}
 			},
@@ -632,7 +521,7 @@ func (tabsLayout *tabsLayoutData) IsListItemEnabled(index int) bool {
 	return true
 }
 
-func (tabsLayout *tabsLayoutData) updateTitle(view View, tag string) {
+func (tabsLayout *tabsLayoutData) updateTitle(view View, tag PropertyName) {
 	session := tabsLayout.session
 	title, _ := stringProperty(view, Title, session)
 	if !GetNotTranslate(tabsLayout) {
@@ -641,13 +530,13 @@ func (tabsLayout *tabsLayoutData) updateTitle(view View, tag string) {
 	session.updateInnerHTML(view.htmlID()+"-title", title)
 }
 
-func (tabsLayout *tabsLayoutData) updateIcon(view View, tag string) {
+func (tabsLayout *tabsLayoutData) updateIcon(view View, tag PropertyName) {
 	session := tabsLayout.session
 	icon, _ := stringProperty(view, Icon, session)
 	session.updateProperty(view.htmlID()+"-icon", "src", icon)
 }
 
-func (tabsLayout *tabsLayoutData) updateTabCloseButton(view View, tag string) {
+func (tabsLayout *tabsLayoutData) updateTabCloseButton(view View, tag PropertyName) {
 	updateInnerHTML(tabsLayout.htmlID(), tabsLayout.session)
 }
 
@@ -662,11 +551,8 @@ func (tabsLayout *tabsLayoutData) Append(view View) {
 		view.SetChangeListener(Icon, tabsLayout.updateIcon)
 		view.SetChangeListener(TabCloseButton, tabsLayout.updateTabCloseButton)
 		if len(tabsLayout.views) == 1 {
-			tabsLayout.properties[Current] = 0
+			tabsLayout.setRaw(Current, nil)
-			for _, listener := range tabsLayout.tabListener {
+			tabsLayout.Set(Current, 0)
-				listener(tabsLayout, 0, -1)
-			}
-			defer tabsLayout.propertyChangedEvent(Current)
 		}
 	}
 }
@@ -677,9 +563,9 @@ func (tabsLayout *tabsLayoutData) Insert(view View, index int) {
 		tabsLayout.views = []View{}
 	}
 	if view != nil {
-		if current := tabsLayout.currentItem(0); current >= index {
+		if current := GetCurrent(tabsLayout); current >= index {
-			tabsLayout.properties[Current] = current + 1
+			tabsLayout.setRaw(Current, current+1)
-			defer tabsLayout.propertyChangedEvent(Current)
+			defer tabsLayout.currentChanged()
 		}
 		tabsLayout.viewsContainerData.Insert(view, index)
 		view.SetChangeListener(Title, tabsLayout.updateTitle)
@@ -688,8 +574,38 @@ func (tabsLayout *tabsLayoutData) Insert(view View, index int) {
 	}
 }
 
+func (tabsLayout *tabsLayoutData) currentChanged() {
+	if listener, ok := tabsLayout.changeListener[Current]; ok {
+		listener(tabsLayout, Current)
+	}
+}
+
 // Remove removes view from list and return it
 func (tabsLayout *tabsLayoutData) RemoveView(index int) View {
+
+	if index < 0 || index >= len(tabsLayout.views) {
+		return nil
+	}
+
+	oldCurrent := GetCurrent(tabsLayout)
+	newCurrent := oldCurrent
+	if index < oldCurrent || (index == oldCurrent && oldCurrent > 0) {
+		newCurrent--
+	}
+
+	if view := tabsLayout.viewsContainerData.RemoveView(index); view != nil {
+		view.SetChangeListener(Title, nil)
+		view.SetChangeListener(Icon, nil)
+		view.SetChangeListener(TabCloseButton, nil)
+
+		if newCurrent != oldCurrent {
+			tabsLayout.setRaw(Current, newCurrent)
+			tabsLayout.currentChanged()
+		}
+	}
+	return nil
+
+	/*
 		if tabsLayout.views == nil {
 			tabsLayout.views = []View{}
 			return nil
@@ -706,7 +622,7 @@ func (tabsLayout *tabsLayoutData) RemoveView(index int) View {
 		view.SetChangeListener(Icon, nil)
 		view.SetChangeListener(TabCloseButton, nil)
 
-	current := tabsLayout.currentItem(0)
+		current := GetCurrent(tabsLayout)
 		if index < current || (index == current && current > 0) {
 			current--
 		}
@@ -725,19 +641,20 @@ func (tabsLayout *tabsLayoutData) RemoveView(index int) View {
 		updateInnerHTML(tabsLayout.parentHTMLID(), tabsLayout.session)
 		tabsLayout.propertyChangedEvent(Content)
 
-	delete(tabsLayout.properties, Current)
+		delete(tabsLayout.view, Current)
-	tabsLayout.set(Current, current)
+		tabsLayout.Set(Current, current)
 		return view
+	*/
 }
 
 func (tabsLayout *tabsLayoutData) htmlProperties(self View, buffer *strings.Builder) {
 	tabsLayout.viewsContainerData.htmlProperties(self, buffer)
 	buffer.WriteString(` data-inactiveTabStyle="`)
-	buffer.WriteString(tabsLayout.inactiveTabStyle())
+	buffer.WriteString(tabsLayoutInactiveTabStyle(tabsLayout))
 	buffer.WriteString(`" data-activeTabStyle="`)
-	buffer.WriteString(tabsLayout.activeTabStyle())
+	buffer.WriteString(tabsLayoutActiveTabStyle(tabsLayout))
 	buffer.WriteString(`" data-current="`)
-	buffer.WriteString(strconv.Itoa(tabsLayout.currentItem(0)))
+	buffer.WriteString(strconv.Itoa(GetCurrent(tabsLayout)))
 	buffer.WriteRune('"')
 }
 
@@ -763,8 +680,7 @@ func (tabsLayout *tabsLayoutData) htmlSubviews(self View, buffer *strings.Builde
 		return
 	}
 
-	//viewCount := len(tabsLayout.views)
+	current := GetCurrent(tabsLayout)
-	current := tabsLayout.currentItem(0)
 	location := tabsLayout.tabsLocation()
 	tabsLayoutID := tabsLayout.htmlID()
 
@@ -796,8 +712,8 @@ func (tabsLayout *tabsLayoutData) htmlSubviews(self View, buffer *strings.Builde
 
 		buffer.WriteString(`">`)
 
-		inactiveStyle := tabsLayout.inactiveTabStyle()
+		inactiveStyle := tabsLayoutInactiveTabStyle(tabsLayout)
-		activeStyle := tabsLayout.activeTabStyle()
+		activeStyle := tabsLayoutActiveTabStyle(tabsLayout)
 
 		notTranslate := GetNotTranslate(tabsLayout)
 		closeButton, _ := boolProperty(tabsLayout, TabCloseButton, tabsLayout.session)
@@ -947,18 +863,18 @@ func (tabsLayout *tabsLayoutData) htmlSubviews(self View, buffer *strings.Builde
 	}
 }
 
-func (tabsLayout *tabsLayoutData) handleCommand(self View, command string, data DataObject) bool {
+func (tabsLayout *tabsLayoutData) handleCommand(self View, command PropertyName, data DataObject) bool {
 	switch command {
 	case "tabClick":
 		if numberText, ok := data.PropertyValue("number"); ok {
 			if number, err := strconv.Atoi(numberText); err == nil {
-				current := tabsLayout.currentItem(0)
+				current := GetCurrent(tabsLayout)
 				if current != number {
-					tabsLayout.properties[Current] = number
+					tabsLayout.setRaw(Current, number)
-					for _, listener := range tabsLayout.tabListener {
+					for _, listener := range getEventWithOldListeners[TabsLayout, int](tabsLayout, nil, CurrentTabChangedEvent) {
 						listener(tabsLayout, number, current)
 					}
-					tabsLayout.propertyChangedEvent(Current)
+					tabsLayout.currentChanged()
 				}
 			}
 		}
@@ -967,7 +883,7 @@ func (tabsLayout *tabsLayoutData) handleCommand(self View, command string, data
 	case "tabCloseClick":
 		if numberText, ok := data.PropertyValue("number"); ok {
 			if number, err := strconv.Atoi(numberText); err == nil {
-				for _, listener := range tabsLayout.tabCloseListener {
+				for _, listener := range getEventListeners[TabsLayout, int](tabsLayout, nil, TabCloseEvent) {
 					listener(tabsLayout, number)
 				}
 			}

textView.go

@@ -23,116 +23,79 @@ func NewTextView(session Session, params Params) TextView {
 }
 
 func newTextView(session Session) View {
-	return NewTextView(session, nil)
+	return new(textViewData)
 }
 
 // Init initialize fields of TextView by default values
 func (textView *textViewData) init(session Session) {
 	textView.viewData.init(session)
 	textView.tag = "TextView"
+	textView.set = textViewSet
+	textView.changed = textViewPropertyChanged
 }
 
-func (textView *textViewData) String() string {
+func textViewPropertyChanged(view View, tag PropertyName) {
-	return getViewString(textView, nil)
-}
-
-func (textView *textViewData) Get(tag string) any {
-	return textView.get(strings.ToLower(tag))
-}
-
-func (textView *textViewData) Remove(tag string) {
-	textView.remove(strings.ToLower(tag))
-}
-
-func (textView *textViewData) remove(tag string) {
-	textView.viewData.remove(tag)
-	if textView.created {
 	switch tag {
 	case Text:
-			updateInnerHTML(textView.htmlID(), textView.session)
+		updateInnerHTML(view.htmlID(), view.Session())
 
 	case TextOverflow:
-			textView.textOverflowUpdated()
+		session := view.Session()
+		if n, ok := enumProperty(view, TextOverflow, session, 0); ok {
+			values := enumProperties[TextOverflow].cssValues
+			if n >= 0 && n < len(values) {
+				session.updateCSSProperty(view.htmlID(), string(TextOverflow), values[n])
+				return
 			}
 		}
+		session.updateCSSProperty(view.htmlID(), string(TextOverflow), "")
+
+	case NotTranslate:
+		updateInnerHTML(view.htmlID(), view.Session())
+
+	default:
+		viewPropertyChanged(view, tag)
+	}
 }
 
-func (textView *textViewData) Set(tag string, value any) bool {
+func textViewSet(view View, tag PropertyName, value any) []PropertyName {
-	return textView.set(strings.ToLower(tag), value)
-}
-
-func (textView *textViewData) set(tag string, value any) bool {
 	switch tag {
 	case Text:
 		switch value := value.(type) {
 		case string:
-			textView.properties[Text] = value
+			view.setRaw(Text, value)
 
 		case fmt.Stringer:
-			textView.properties[Text] = value.String()
+			view.setRaw(Text, value.String())
 
 		case float32:
-			textView.properties[Text] = fmt.Sprintf("%g", float64(value))
+			view.setRaw(Text, fmt.Sprintf("%g", float64(value)))
 
 		case float64:
-			textView.properties[Text] = fmt.Sprintf("%g", value)
+			view.setRaw(Text, fmt.Sprintf("%g", value))
 
 		case []rune:
-			textView.properties[Text] = string(value)
+			view.setRaw(Text, string(value))
 
 		case bool:
 			if value {
-				textView.properties[Text] = "true"
+				view.setRaw(Text, "true")
 			} else {
-				textView.properties[Text] = "false"
+				view.setRaw(Text, "false")
 			}
 
 		default:
 			if n, ok := isInt(value); ok {
-				textView.properties[Text] = fmt.Sprintf("%d", n)
+				view.setRaw(Text, fmt.Sprintf("%d", n))
 			} else {
 				notCompatibleType(tag, value)
-				return false
+				return nil
 			}
 		}
-		if textView.created {
+		return []PropertyName{Text}
-			updateInnerHTML(textView.htmlID(), textView.session)
 	}
 
-	case TextOverflow:
+	return viewSet(view, tag, value)
-		if !textView.viewData.set(tag, value) {
-			return false
-		}
-		if textView.created {
-			textView.textOverflowUpdated()
-		}
-
-	case NotTranslate:
-		if !textView.viewData.set(tag, value) {
-			return false
-		}
-		if textView.created {
-			updateInnerHTML(textView.htmlID(), textView.Session())
-		}
-
-	default:
-		return textView.viewData.set(tag, value)
-	}
-
-	textView.propertyChangedEvent(tag)
-	return true
-}
-
-func (textView *textViewData) textOverflowUpdated() {
-	session := textView.Session()
-	if n, ok := enumProperty(textView, TextOverflow, session, 0); ok {
-		values := enumProperties[TextOverflow].cssValues
-		if n >= 0 && n < len(values) {
-			session.updateCSSProperty(textView.htmlID(), TextOverflow, values[n])
-			return
-		}
-	}
-	session.updateCSSProperty(textView.htmlID(), TextOverflow, "")
 }
 
 func (textView *textViewData) htmlSubviews(self View, buffer *strings.Builder) {

theme.go

@@ -699,13 +699,13 @@ func (theme *theme) addText(themeText string) bool {
 			if node := obj.Property(i); node != nil {
 				switch node.Type() {
 				case ArrayNode:
-					params[node.Tag()] = node.ArrayElements()
+					params[PropertyName(node.Tag())] = node.ArrayElements()
 
 				case ObjectNode:
-					params[node.Tag()] = node.Object()
+					params[PropertyName(node.Tag())] = node.Object()
 
 				default:
-					params[node.Tag()] = node.Text()
+					params[PropertyName(node.Tag())] = node.Text()
 				}
 			}
 		}

timePicker.go

@@ -27,7 +27,7 @@ const (
 	// `func(newTime time.Time)`,
 	// `func(picker rui.TimePicker)`,
 	// `func()`.
-	TimeChangedEvent = "time-changed"
+	TimeChangedEvent PropertyName = "time-changed"
 
 	// TimePickerMin is the constant for "time-picker-min" property tag.
 	//
@@ -44,7 +44,7 @@ const (
 	// "HH:MM:SS PM" - "08:15:00 AM".
 	// "HH:MM" - "08:15".
 	// "HH:MM PM" - "08:15 AM".
-	TimePickerMin = "time-picker-min"
+	TimePickerMin PropertyName = "time-picker-min"
 
 	// TimePickerMax is the constant for "time-picker-max" property tag.
 	//
@@ -61,7 +61,7 @@ const (
 	// "HH:MM:SS PM" - "08:15:00 AM".
 	// "HH:MM" - "08:15".
 	// "HH:MM PM" - "08:15 AM".
-	TimePickerMax = "time-picker-max"
+	TimePickerMax PropertyName = "time-picker-max"
 
 	// TimePickerStep is the constant for "time-picker-step" property tag.
 	//
@@ -72,7 +72,7 @@ const (
 	//
 	// Values:
 	// >= `0` or >= "0" - Step value in seconds used to increment or decrement time.
-	TimePickerStep = "time-picker-step"
+	TimePickerStep PropertyName = "time-picker-step"
 
 	// TimePickerValue is the constant for "time-picker-value" property tag.
 	//
@@ -89,7 +89,7 @@ const (
 	// "HH:MM:SS PM" - "08:15:00 AM".
 	// "HH:MM" - "08:15".
 	// "HH:MM PM" - "08:15 AM".
-	TimePickerValue = "time-picker-value"
+	TimePickerValue PropertyName = "time-picker-value"
 
 	timeFormat = "15:04:05"
 )
@@ -101,8 +101,6 @@ type TimePicker interface {
 
 type timePickerData struct {
 	viewData
-	dataList
-	timeChangedListeners []func(TimePicker, time.Time, time.Time)
 }
 
 // NewTimePicker create new TimePicker object and return it
@@ -114,116 +112,38 @@ func NewTimePicker(session Session, params Params) TimePicker {
 }
 
 func newTimePicker(session Session) View {
-	return NewTimePicker(session, nil)
+	return new(timePickerData)
 }
 
 func (picker *timePickerData) init(session Session) {
 	picker.viewData.init(session)
 	picker.tag = "TimePicker"
 	picker.hasHtmlDisabled = true
-	picker.timeChangedListeners = []func(TimePicker, time.Time, time.Time){}
+	picker.normalize = normalizeTimePickerTag
-	picker.dataListInit()
+	picker.set = timePickerSet
-}
+	picker.changed = timePickerPropertyChanged
-
-func (picker *timePickerData) String() string {
-	return getViewString(picker, nil)
 }
 
 func (picker *timePickerData) Focusable() bool {
 	return true
 }
 
-func (picker *timePickerData) normalizeTag(tag string) string {
+func normalizeTimePickerTag(tag PropertyName) PropertyName {
-	tag = strings.ToLower(tag)
+	tag = defaultNormalize(tag)
 	switch tag {
 	case Type, Min, Max, Step, Value:
 		return "time-picker-" + tag
 	}
 
-	return tag
+	return normalizeDataListTag(tag)
 }
 
-func (picker *timePickerData) Remove(tag string) {
+func stringToTime(value string) (time.Time, bool) {
-	picker.remove(picker.normalizeTag(tag))
+	lowText := strings.ToUpper(value)
-}
+	pm := strings.HasSuffix(lowText, "PM") || strings.HasSuffix(lowText, "AM")
-
-func (picker *timePickerData) remove(tag string) {
-	switch tag {
-	case TimeChangedEvent:
-		if len(picker.timeChangedListeners) > 0 {
-			picker.timeChangedListeners = []func(TimePicker, time.Time, time.Time){}
-			picker.propertyChangedEvent(tag)
-		}
-		return
-
-	case TimePickerMin:
-		delete(picker.properties, TimePickerMin)
-		if picker.created {
-			picker.session.removeProperty(picker.htmlID(), Min)
-		}
-
-	case TimePickerMax:
-		delete(picker.properties, TimePickerMax)
-		if picker.created {
-			picker.session.removeProperty(picker.htmlID(), Max)
-		}
-
-	case TimePickerStep:
-		delete(picker.properties, TimePickerStep)
-		if picker.created {
-			picker.session.removeProperty(picker.htmlID(), Step)
-		}
-
-	case TimePickerValue:
-		if _, ok := picker.properties[TimePickerValue]; ok {
-			oldTime := GetTimePickerValue(picker)
-			delete(picker.properties, TimePickerValue)
-			time := GetTimePickerValue(picker)
-			if picker.created {
-				picker.session.callFunc("setInputValue", picker.htmlID(), time.Format(timeFormat))
-			}
-			for _, listener := range picker.timeChangedListeners {
-				listener(picker, time, oldTime)
-			}
-		} else {
-			return
-		}
-
-	case DataList:
-		if len(picker.dataList.dataList) > 0 {
-			picker.setDataList(picker, []string{}, true)
-		}
-
-	default:
-		picker.viewData.remove(tag)
-		return
-	}
-	picker.propertyChangedEvent(tag)
-}
-
-func (picker *timePickerData) Set(tag string, value any) bool {
-	return picker.set(picker.normalizeTag(tag), value)
-}
-
-func (picker *timePickerData) set(tag string, value any) bool {
-	if value == nil {
-		picker.remove(tag)
-		return true
-	}
-
-	setTimeValue := func(tag string) (time.Time, bool) {
-		switch value := value.(type) {
-		case time.Time:
-			picker.properties[tag] = value
-			return value, true
-
-		case string:
-			if text, ok := picker.Session().resolveConstants(value); ok {
-				lowText := strings.ToLower(text)
-				pm := strings.HasSuffix(lowText, "pm") || strings.HasSuffix(lowText, "am")
 
 	var format string
-				switch len(strings.Split(text, ":")) {
+	switch len(strings.Split(value, ":")) {
 	case 2:
 		if pm {
 			format = "3:04 PM"
@@ -239,111 +159,107 @@ func (picker *timePickerData) set(tag string, value any) bool {
 		}
 	}
 
-				if time, err := time.Parse(format, text); err == nil {
+	result, err := time.Parse(format, value)
-					picker.properties[tag] = value
+	if err != nil {
-					return time, true
-				} else {
 		ErrorLog(err.Error())
-				}
 		return time.Now(), false
 	}
+	return result, true
+}
+
+func timePickerSet(view View, tag PropertyName, value any) []PropertyName {
+
+	setTimeValue := func(tag PropertyName) []PropertyName {
+		switch value := value.(type) {
+		case time.Time:
+			view.setRaw(tag, value)
+			return []PropertyName{tag}
+
+		case string:
+			if isConstantName(value) {
+				view.setRaw(tag, value)
+				return []PropertyName{tag}
+			}
+
+			if time, ok := stringToTime(value); ok {
+				view.setRaw(tag, time)
+				return []PropertyName{tag}
+			}
 		}
 
 		notCompatibleType(tag, value)
-		return time.Now(), false
+		return nil
 	}
 
 	switch tag {
 	case TimePickerMin:
-		old, oldOK := getTimeProperty(picker, TimePickerMin, Min)
+		return setTimeValue(TimePickerMin)
-		if time, ok := setTimeValue(TimePickerMin); ok {
+
-			if !oldOK || time != old {
+	case TimePickerMax:
-				if picker.created {
+		return setTimeValue(TimePickerMax)
-					picker.session.updateProperty(picker.htmlID(), Min, time.Format(timeFormat))
+
+	case TimePickerStep:
+		return setIntProperty(view, TimePickerStep, value)
+
+	case TimePickerValue:
+		view.setRaw("old-time", GetTimePickerValue(view))
+		return setTimeValue(tag)
+
+	case TimeChangedEvent:
+		return setEventWithOldListener[TimePicker, time.Time](view, tag, value)
+
+	case DataList:
+		return setDataList(view, value, timeFormat)
 	}
-				picker.propertyChangedEvent(tag)
+
+	return viewSet(view, tag, value)
 }
-			return true
+
+func timePickerPropertyChanged(view View, tag PropertyName) {
+
+	session := view.Session()
+
+	switch tag {
+
+	case TimePickerMin:
+		if time, ok := GetTimePickerMin(view); ok {
+			session.updateProperty(view.htmlID(), "min", time.Format(timeFormat))
+		} else {
+			session.removeProperty(view.htmlID(), "min")
 		}
 
 	case TimePickerMax:
-		old, oldOK := getTimeProperty(picker, TimePickerMax, Max)
+		if time, ok := GetTimePickerMax(view); ok {
-		if time, ok := setTimeValue(TimePickerMax); ok {
+			session.updateProperty(view.htmlID(), "max", time.Format(timeFormat))
-			if !oldOK || time != old {
+		} else {
-				if picker.created {
+			session.removeProperty(view.htmlID(), "max")
-					picker.session.updateProperty(picker.htmlID(), Max, time.Format(timeFormat))
-				}
-				picker.propertyChangedEvent(tag)
-			}
-			return true
 		}
 
 	case TimePickerStep:
-		oldStep := GetTimePickerStep(picker)
+		if step := GetTimePickerStep(view); step > 0 {
-		if picker.setIntProperty(TimePickerStep, value) {
+			session.updateProperty(view.htmlID(), "step", strconv.Itoa(step))
-			if step := GetTimePickerStep(picker); oldStep != step {
-				if picker.created {
-					if step > 0 {
-						picker.session.updateProperty(picker.htmlID(), Step, strconv.Itoa(step))
 		} else {
-						picker.session.removeProperty(picker.htmlID(), Step)
+			session.removeProperty(view.htmlID(), "step")
-					}
-				}
-				picker.propertyChangedEvent(tag)
-			}
-			return true
 		}
 
 	case TimePickerValue:
-		oldTime := GetTimePickerValue(picker)
+		value := GetTimePickerValue(view)
-		if time, ok := setTimeValue(TimePickerValue); ok {
+		session.callFunc("setInputValue", view.htmlID(), value.Format(timeFormat))
-			if time != oldTime {
-				if picker.created {
-					picker.session.callFunc("setInputValue", picker.htmlID(), time.Format(timeFormat))
-				}
-				for _, listener := range picker.timeChangedListeners {
-					listener(picker, time, oldTime)
-				}
-				picker.propertyChangedEvent(tag)
-			}
-			return true
-		}
 
-	case TimeChangedEvent:
+		if listeners := GetTimeChangedListeners(view); len(listeners) > 0 {
-		listeners, ok := valueToEventWithOldListeners[TimePicker, time.Time](value)
+			oldTime := time.Now()
-		if !ok {
+			if val := view.getRaw("old-time"); val != nil {
-			notCompatibleType(tag, value)
+				if time, ok := val.(time.Time); ok {
-			return false
+					oldTime = time
-		} else if listeners == nil {
+				}
-			listeners = []func(TimePicker, time.Time, time.Time){}
+			}
+			for _, listener := range listeners {
+				listener(view, value, oldTime)
+			}
 		}
-		picker.timeChangedListeners = listeners
-		picker.propertyChangedEvent(tag)
-		return true
-
-	case DataList:
-		return picker.setDataList(picker, value, picker.created)
 
 	default:
-		return picker.viewData.set(tag, value)
+		viewPropertyChanged(view, tag)
-	}
-	return false
-}
-
-func (picker *timePickerData) Get(tag string) any {
-	return picker.get(picker.normalizeTag(tag))
-}
-
-func (picker *timePickerData) get(tag string) any {
-	switch tag {
-	case TimeChangedEvent:
-		return picker.timeChangedListeners
-
-	case DataList:
-		return picker.dataList.dataList
-
-	default:
-		return picker.viewData.get(tag)
 	}
 }
 
@@ -352,7 +268,13 @@ func (picker *timePickerData) htmlTag() string {
 }
 
 func (picker *timePickerData) htmlSubviews(self View, buffer *strings.Builder) {
-	picker.dataListHtmlSubviews(self, buffer)
+	dataListHtmlSubviews(self, buffer, func(text string, session Session) string {
+		text, _ = session.resolveConstants(text)
+		if time, ok := stringToTime(text); ok {
+			return time.Format(timeFormat)
+		}
+		return text
+	})
 }
 
 func (picker *timePickerData) htmlProperties(self View, buffer *strings.Builder) {
@@ -387,10 +309,10 @@ func (picker *timePickerData) htmlProperties(self View, buffer *strings.Builder)
 		buffer.WriteString(` onclick="stopEventPropagation(this, event)"`)
 	}
 
-	picker.dataListHtmlProperties(picker, buffer)
+	dataListHtmlProperties(picker, buffer)
 }
 
-func (picker *timePickerData) handleCommand(self View, command string, data DataObject) bool {
+func (picker *timePickerData) handleCommand(self View, command PropertyName, data DataObject) bool {
 	switch command {
 	case "textChanged":
 		if text, ok := data.PropertyValue("text"); ok {
@@ -398,9 +320,13 @@ func (picker *timePickerData) handleCommand(self View, command string, data Data
 				oldValue := GetTimePickerValue(picker)
 				picker.properties[TimePickerValue] = value
 				if value != oldValue {
-					for _, listener := range picker.timeChangedListeners {
+					for _, listener := range GetTimeChangedListeners(picker) {
 						listener(picker, value, oldValue)
 					}
+					if listener, ok := picker.changeListener[TimePickerValue]; ok {
+						listener(picker, TimePickerValue)
+					}
+
 				}
 			}
 		}
@@ -410,7 +336,7 @@ func (picker *timePickerData) handleCommand(self View, command string, data Data
 	return picker.viewData.handleCommand(self, command, data)
 }
 
-func getTimeProperty(view View, mainTag, shortTag string) (time.Time, bool) {
+func getTimeProperty(view View, mainTag, shortTag PropertyName) (time.Time, bool) {
 	valueToTime := func(value any) (time.Time, bool) {
 		if value != nil {
 			switch value := value.(type) {
@@ -419,7 +345,7 @@ func getTimeProperty(view View, mainTag, shortTag string) (time.Time, bool) {
 
 			case string:
 				if text, ok := view.Session().resolveConstants(value); ok {
-					if result, err := time.Parse(timeFormat, text); err == nil {
+					if result, ok := stringToTime(text); ok {
 						return result, true
 					}
 				}
@@ -433,12 +359,14 @@ func getTimeProperty(view View, mainTag, shortTag string) (time.Time, bool) {
 			return result, true
 		}
 
-		if value := valueFromStyle(view, shortTag); value != nil {
+		for _, tag := range []PropertyName{mainTag, shortTag} {
+			if value := valueFromStyle(view, tag); value != nil {
 				if result, ok := valueToTime(value); ok {
 					return result, true
 				}
 			}
 		}
+	}
 
 	return time.Now(), false
 }

touchEvents.go

@@ -2,7 +2,6 @@ package rui
 
 import (
 	"strconv"
-	"strings"
 )
 
 // Constants which represent [View] specific touch events properties
@@ -23,7 +22,7 @@ const (
 	// `func(event rui.TouchEvent)`,
 	// `func(view rui.View)`,
 	// `func()`.
-	TouchStart = "touch-start"
+	TouchStart PropertyName = "touch-start"
 
 	// TouchEnd is the constant for "touch-end" property tag.
 	//
@@ -41,7 +40,7 @@ const (
 	// `func(event rui.TouchEvent)`,
 	// `func(view rui.View)`,
 	// `func()`.
-	TouchEnd = "touch-end"
+	TouchEnd PropertyName = "touch-end"
 
 	// TouchMove is the constant for "touch-move" property tag.
 	//
@@ -59,7 +58,7 @@ const (
 	// `func(event rui.TouchEvent)`,
 	// `func(view rui.View)`,
 	// `func()`.
-	TouchMove = "touch-move"
+	TouchMove PropertyName = "touch-move"
 
 	// TouchCancel is the constant for "touch-cancel" property tag.
 	//
@@ -78,7 +77,7 @@ const (
 	// `func(event rui.TouchEvent)`,
 	// `func(view rui.View)`,
 	// `func()`.
-	TouchCancel = "touch-cancel"
+	TouchCancel PropertyName = "touch-cancel"
 )
 
 // Touch contains parameters of a single touch of a touch event
@@ -143,45 +142,33 @@ type TouchEvent struct {
 	MetaKey bool
 }
 
-var touchEvents = map[string]struct{ jsEvent, jsFunc string }{
+/*
-	TouchStart:  {jsEvent: "ontouchstart", jsFunc: "touchStartEvent"},
+func setTouchListener(properties Properties, tag PropertyName, value any) bool {
-	TouchEnd:    {jsEvent: "ontouchend", jsFunc: "touchEndEvent"},
+	if listeners, ok := valueToEventListeners[View, TouchEvent](value); ok {
-	TouchMove:   {jsEvent: "ontouchmove", jsFunc: "touchMoveEvent"},
+		if len(listeners) == 0 {
-	TouchCancel: {jsEvent: "ontouchcancel", jsFunc: "touchCancelEvent"},
+			properties.setRaw(tag, nil)
+		} else {
+			properties.setRaw(tag, listeners)
+		}
+		return true
 	}
-
-func (view *viewData) setTouchListener(tag string, value any) bool {
-	listeners, ok := valueToEventListeners[View, TouchEvent](value)
-	if !ok {
 	notCompatibleType(tag, value)
 	return false
 }
 
-	if listeners == nil {
+func (view *viewData) removeTouchListener(tag PropertyName) {
-		view.removeTouchListener(tag)
-	} else if js, ok := touchEvents[tag]; ok {
-		view.properties[tag] = listeners
-		if view.created {
-			view.session.updateProperty(view.htmlID(), js.jsEvent, js.jsFunc+"(this, event)")
-		}
-	} else {
-		return false
-	}
-	return true
-}
-
-func (view *viewData) removeTouchListener(tag string) {
 	delete(view.properties, tag)
 	if view.created {
-		if js, ok := touchEvents[tag]; ok {
+		if js, ok := eventJsFunc[tag]; ok {
 			view.session.removeProperty(view.htmlID(), js.jsEvent)
 		}
 	}
 }
 
 func touchEventsHtml(view View, buffer *strings.Builder) {
-	for tag, js := range touchEvents {
+	for _, tag := range []PropertyName{TouchStart, TouchEnd, TouchMove, TouchCancel} {
 		if value := view.getRaw(tag); value != nil {
+			if js, ok := eventJsFunc[tag]; ok {
 				if listeners, ok := value.([]func(View, TouchEvent)); ok && len(listeners) > 0 {
 					buffer.WriteString(js.jsEvent)
 					buffer.WriteString(`="`)
@@ -191,6 +178,8 @@ func touchEventsHtml(view View, buffer *strings.Builder) {
 			}
 		}
 	}
+}
+*/
 
 func (event *TouchEvent) init(data DataObject) {
 
@@ -225,7 +214,7 @@ func (event *TouchEvent) init(data DataObject) {
 	event.MetaKey = dataBoolProperty(data, "metaKey")
 }
 
-func handleTouchEvents(view View, tag string, data DataObject) {
+func handleTouchEvents(view View, tag PropertyName, data DataObject) {
 	listeners := getEventListeners[View, TouchEvent](view, nil, tag)
 	if len(listeners) == 0 {
 		return

videoPlayer.go

@@ -15,7 +15,7 @@ const (
 	//
 	// Values:
 	// Internal type is `float`, other types converted to it during assignment.
-	VideoWidth = "video-width"
+	VideoWidth PropertyName = "video-width"
 
 	// VideoHeight is the constant for "video-height" property tag.
 	//
@@ -25,7 +25,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	VideoHeight = "video-height"
+	VideoHeight PropertyName = "video-height"
 
 	// Poster is the constant for "poster" property tag.
 	//
@@ -34,7 +34,7 @@ const (
 	// displayed until the first frame is available, then the first frame is shown as the poster frame.
 	//
 	// Supported types: `string`.
-	Poster = "poster"
+	Poster PropertyName = "poster"
 )
 
 // VideoPlayer is a type of a [View] which can play video files
@@ -50,70 +50,33 @@ type videoPlayerData struct {
 func NewVideoPlayer(session Session, params Params) VideoPlayer {
 	view := new(videoPlayerData)
 	view.init(session)
-	view.tag = "VideoPlayer"
 	setInitParams(view, params)
 	return view
 }
 
 func newVideoPlayer(session Session) View {
-	return NewVideoPlayer(session, nil)
+	return new(videoPlayerData) // NewVideoPlayer(session, nil)
 }
 
 func (player *videoPlayerData) init(session Session) {
 	player.mediaPlayerData.init(session)
 	player.tag = "VideoPlayer"
-}
+	player.changed = videoPlayerPropertyChanged
-
-func (player *videoPlayerData) String() string {
-	return getViewString(player, nil)
 }
 
 func (player *videoPlayerData) htmlTag() string {
 	return "video"
 }
 
-func (player *videoPlayerData) Remove(tag string) {
+func videoPlayerPropertyChanged(view View, tag PropertyName) {
-	player.remove(strings.ToLower(tag))
-}
 
-func (player *videoPlayerData) remove(tag string) {
+	session := view.Session()
-	switch tag {
-
-	case VideoWidth:
-		delete(player.properties, tag)
-		player.session.removeProperty(player.htmlID(), "width")
-
-	case VideoHeight:
-		delete(player.properties, tag)
-		player.session.removeProperty(player.htmlID(), "height")
-
-	case Poster:
-		delete(player.properties, tag)
-		player.session.removeProperty(player.htmlID(), Poster)
-
-	default:
-		player.mediaPlayerData.remove(tag)
-	}
-}
-
-func (player *videoPlayerData) Set(tag string, value any) bool {
-	return player.set(strings.ToLower(tag), value)
-}
-
-func (player *videoPlayerData) set(tag string, value any) bool {
-	if value == nil {
-		player.remove(tag)
-		return true
-	}
-
-	if player.mediaPlayerData.set(tag, value) {
-		session := player.Session()
 	updateSize := func(cssTag string) {
-			if size, ok := floatTextProperty(player, tag, session, 0); ok {
+		if size, ok := floatTextProperty(view, tag, session, 0); ok {
 			if size != "0" {
-					session.updateProperty(player.htmlID(), cssTag, size)
+				session.updateProperty(view.htmlID(), cssTag, size)
 			} else {
-					session.removeProperty(player.htmlID(), cssTag)
+				session.removeProperty(view.htmlID(), cssTag)
 			}
 		}
 	}
@@ -126,14 +89,15 @@ func (player *videoPlayerData) set(tag string, value any) bool {
 		updateSize("height")
 
 	case Poster:
-			if url, ok := stringProperty(player, Poster, session); ok {
+		if url, ok := stringProperty(view, Poster, session); ok {
-				session.updateProperty(player.htmlID(), Poster, url)
+			session.updateProperty(view.htmlID(), string(Poster), url)
-			}
+		} else {
-		}
+			session.removeProperty(view.htmlID(), string(Poster))
-		return true
 		}
 
-	return false
+	default:
+		mediaPlayerPropertyChanged(view, tag)
+	}
 }
 
 func (player *videoPlayerData) htmlProperties(self View, buffer *strings.Builder) {

view.go

@@ -62,15 +62,16 @@ type View interface {
 	// SetAnimated sets the value (second argument) of the property with name defined by the first argument.
 	// Return "true" if the value has been set, in the opposite case "false" are returned and
 	// a description of the error is written to the log
-	SetAnimated(tag string, value any, animation Animation) bool
+	SetAnimated(tag PropertyName, value any, animation Animation) bool
 
 	// SetChangeListener set the function to track the change of the View property
-	SetChangeListener(tag string, listener func(View, string))
+	SetChangeListener(tag PropertyName, listener func(View, PropertyName))
 
 	// HasFocus returns 'true' if the view has focus
 	HasFocus() bool
 
-	handleCommand(self View, command string, data DataObject) bool
+	init(session Session)
+	handleCommand(self View, command PropertyName, data DataObject) bool
 	htmlClass(disabled bool) string
 	htmlTag() string
 	closeHTMLTag() bool
@@ -81,7 +82,8 @@ type View interface {
 	htmlProperties(self View, buffer *strings.Builder)
 	cssStyle(self View, builder cssBuilder)
 	addToCSSStyle(addCSS map[string]string)
-	exscludeTags() []string
+	exscludeTags() []PropertyName
+	htmlDisabledProperty() bool
 
 	onResize(self View, x, y, width, height float64)
 	onItemResize(self View, index string, x, y, width, height float64)
@@ -99,8 +101,8 @@ type viewData struct {
 	_htmlID          string
 	parentID         string
 	systemClass      string
-	changeListener   map[string]func(View, string)
+	changeListener   map[PropertyName]func(View, PropertyName)
-	singleTransition map[string]Animation
+	singleTransition map[PropertyName]Animation
 	addCSS           map[string]string
 	frame            Frame
 	scroll           Frame
@@ -108,12 +110,21 @@ type viewData struct {
 	created          bool
 	hasFocus         bool
 	hasHtmlDisabled  bool
-	//animation map[string]AnimationEndListener
+	getFunc          func(view View, tag PropertyName) any
+	set              func(view View, tag PropertyName, value any) []PropertyName
+	remove           func(view View, tag PropertyName) []PropertyName
+	changed          func(view View, tag PropertyName)
 }
 
 func newView(session Session) View {
+	return new(viewData)
+}
+
+// NewView create new View object and return it
+func NewView(session Session, params Params) View {
 	view := new(viewData)
 	view.init(session)
+	setInitParams(view, params)
 	return view
 }
 
@@ -132,22 +143,18 @@ func setInitParams(view View, params Params) {
 	}
 }
 
-// NewView create new View object and return it
-func NewView(session Session, params Params) View {
-	view := new(viewData)
-	view.init(session)
-	setInitParams(view, params)
-	return view
-}
-
 func (view *viewData) init(session Session) {
 	view.viewStyle.init()
+	view.getFunc = viewGet
+	view.set = viewSet
+	view.normalize = normalizeViewTag
+	view.changed = viewPropertyChanged
 	view.tag = "View"
 	view.session = session
-	view.changeListener = map[string]func(View, string){}
+	view.changeListener = map[PropertyName]func(View, PropertyName){}
 	view.addCSS = map[string]string{}
 	//view.animation = map[string]AnimationEndListener{}
-	view.singleTransition = map[string]Animation{}
+	view.singleTransition = map[PropertyName]Animation{}
 	view.noResizeEvent = false
 	view.created = false
 	view.hasHtmlDisabled = false
@@ -205,71 +212,112 @@ func (view *viewData) Focusable() bool {
 	return false
 }
 
-func (view *viewData) Remove(tag string) {
+func (view *viewData) Remove(tag PropertyName) {
-	view.remove(strings.ToLower(tag))
+	tag = view.normalize(tag)
-}
+	var changedTags []PropertyName = nil
 
-func (view *viewData) remove(tag string) {
 	switch tag {
 	case ID:
+		if view.viewID != "" {
 			view.viewID = ""
-
+			changedTags = []PropertyName{ID}
-	case TabIndex, "tab-index":
-		delete(view.properties, tag)
-		if view.Focusable() {
-			view.session.updateProperty(view.htmlID(), "tabindex", "0")
-		} else {
-			view.session.updateProperty(view.htmlID(), "tabindex", "-1")
 		}
 
-	case UserData:
+	case AnimationTag:
-		delete(view.properties, tag)
+		if val := view.getRaw(AnimationTag); val != nil {
-
+			if animations, ok := val.([]Animation); ok {
-	case Style, StyleDisabled:
+				for _, animation := range animations {
-		if _, ok := view.properties[tag]; ok {
+					animation.unused(view.session)
-			delete(view.properties, tag)
+				}
-			view.session.updateProperty(view.htmlID(), "class", view.htmlClass(IsDisabled(view)))
 			}
 
-	case FocusEvent, LostFocusEvent:
+			view.setRaw(AnimationTag, nil)
-		view.removeFocusListener(tag)
+			changedTags = []PropertyName{AnimationTag}
-
-	case KeyDownEvent, KeyUpEvent:
-		view.removeKeyListener(tag)
-
-	case ClickEvent, DoubleClickEvent, MouseDown, MouseUp, MouseMove, MouseOut, MouseOver, ContextMenuEvent:
-		view.removeMouseListener(tag)
-
-	case PointerDown, PointerUp, PointerMove, PointerOut, PointerOver, PointerCancel:
-		view.removePointerListener(tag)
-
-	case TouchStart, TouchEnd, TouchMove, TouchCancel:
-		view.removeTouchListener(tag)
-
-	case TransitionRunEvent, TransitionStartEvent, TransitionEndEvent, TransitionCancelEvent:
-		view.removeTransitionListener(tag)
-
-	case AnimationStartEvent, AnimationEndEvent, AnimationIterationEvent, AnimationCancelEvent:
-		view.removeAnimationListener(tag)
-
-	case ResizeEvent, ScrollEvent:
-		delete(view.properties, tag)
-
-	case Content:
-		if _, ok := view.properties[Content]; ok {
-			delete(view.properties, Content)
-			updateInnerHTML(view.htmlID(), view.session)
 		}
 
 	default:
-		view.viewStyle.remove(tag)
+		changedTags = view.remove(view, tag)
-		viewPropertyChanged(view, tag)
 	}
 
-	view.propertyChangedEvent(tag)
+	if view.created && len(changedTags) > 0 {
+		for _, tag := range changedTags {
+			view.changed(view, tag)
 		}
 
-func (view *viewData) propertyChangedEvent(tag string) {
+		for _, tag := range changedTags {
+			if listener, ok := view.changeListener[tag]; ok {
+				listener(view, tag)
+			}
+		}
+	}
+}
+
+func (view *viewData) Set(tag PropertyName, value any) bool {
+	if value == nil {
+		view.Remove(tag)
+		return true
+	}
+
+	tag = view.normalize(tag)
+	var changedTags []PropertyName = nil
+
+	switch tag {
+	case ID:
+		text, ok := value.(string)
+		if !ok {
+			notCompatibleType(ID, value)
+			return false
+		}
+		view.viewID = text
+		changedTags = []PropertyName{ID}
+
+	case AnimationTag:
+		oldAnimations := []Animation{}
+		if val := view.getRaw(AnimationTag); val != nil {
+			if animation, ok := val.([]Animation); ok {
+				oldAnimations = animation
+			}
+		}
+
+		if !setAnimationProperty(view, tag, value) {
+			return false
+		}
+
+		for _, animation := range oldAnimations {
+			animation.unused(view.session)
+		}
+		changedTags = []PropertyName{AnimationTag}
+
+	default:
+		changedTags = viewSet(view, tag, value)
+	}
+
+	if view.created && len(changedTags) > 0 {
+		for _, tag := range changedTags {
+			view.changed(view, tag)
+		}
+
+		for _, tag := range changedTags {
+			if listener, ok := view.changeListener[tag]; ok {
+				listener(view, tag)
+			}
+		}
+	}
+
+	return changedTags != nil
+}
+
+func normalizeViewTag(tag PropertyName) PropertyName {
+	tag = normalizeViewStyleTag(tag)
+	switch tag {
+	case "tab-index":
+		return TabIndex
+	}
+	return tag
+}
+
+/*
+func (view *viewData) propertyChangedEvent(tag PropertyName) {
 	if listener, ok := view.changeListener[tag]; ok {
 		listener(view, tag)
 	}
@@ -319,113 +367,58 @@ func (view *viewData) propertyChangedEvent(tag string) {
 		listener(view, tag)
 	}
 }
+*/
 
-func (view *viewData) Set(tag string, value any) bool {
+func viewRemove(properties Properties, tag PropertyName) []PropertyName {
-	return view.set(strings.ToLower(tag), value)
+	return viewStyleRemove(properties, tag)
 }
 
-func (view *viewData) set(tag string, value any) bool {
+func viewSet(view View, tag PropertyName, value any) []PropertyName {
-	if value == nil {
-		view.remove(tag)
-		return true
-	}
-
-	result := func(res bool) bool {
-		if res {
-			view.propertyChangedEvent(tag)
-		}
-		return res
-	}
 
 	switch tag {
-	case ID:
-		text, ok := value.(string)
-		if !ok {
-			notCompatibleType(ID, value)
-			return false
-		}
-		view.viewID = text
-
-	case AnimationTag:
-		oldAnimations := []Animation{}
-		if val, ok := view.properties[AnimationTag]; ok && val != nil {
-			if animation, ok := val.([]Animation); ok {
-				oldAnimations = animation
-			}
-		}
-
-		if !view.setAnimation(tag, value) {
-			return false
-		}
-
-		for _, animation := range oldAnimations {
-			animation.unused(view.session)
-		}
-		if view.created {
-			viewPropertyChanged(view, tag)
-		}
 
 	case TabIndex, "tab-index":
-		if !view.setIntProperty(tag, value) {
+		return setIntProperty(view, TabIndex, value)
-			return false
-		}
-		if value, ok := intProperty(view, TabIndex, view.Session(), 0); ok {
-			view.session.updateProperty(view.htmlID(), "tabindex", strconv.Itoa(value))
-		} else if view.Focusable() {
-			view.session.updateProperty(view.htmlID(), "tabindex", "0")
-		} else {
-			view.session.updateProperty(view.htmlID(), "tabindex", "-1")
-		}
 
 	case UserData:
-		view.properties[tag] = value
+		view.setRaw(tag, value)
+		return []PropertyName{UserData}
 
 	case Style, StyleDisabled:
-		text, ok := value.(string)
+		if text, ok := value.(string); ok {
-		if !ok {
+			view.setRaw(tag, text)
+			return []PropertyName{tag}
+		}
 		notCompatibleType(ID, value)
-			return false
+		return nil
-		}
-		view.properties[tag] = text
-		if view.created {
-			view.session.updateProperty(view.htmlID(), "class", view.htmlClass(IsDisabled(view)))
-		}
 
 	case FocusEvent, LostFocusEvent:
-		return result(view.setFocusListener(tag, value))
+		return setNoParamEventListener[View](view, tag, value)
 
 	case KeyDownEvent, KeyUpEvent:
-		return result(view.setKeyListener(tag, value))
+		return setViewEventListener[View, KeyEvent](view, tag, value)
 
 	case ClickEvent, DoubleClickEvent, MouseDown, MouseUp, MouseMove, MouseOut, MouseOver, ContextMenuEvent:
-		return result(view.setMouseListener(tag, value))
+		return setViewEventListener[View, MouseEvent](view, tag, value)
 
 	case PointerDown, PointerUp, PointerMove, PointerOut, PointerOver, PointerCancel:
-		return result(view.setPointerListener(tag, value))
+		return setViewEventListener[View, PointerEvent](view, tag, value)
 
 	case TouchStart, TouchEnd, TouchMove, TouchCancel:
-		return result(view.setTouchListener(tag, value))
+		return setViewEventListener[View, TouchEvent](view, tag, value)
 
-	case TransitionRunEvent, TransitionStartEvent, TransitionEndEvent, TransitionCancelEvent:
+	case TransitionRunEvent, TransitionStartEvent, TransitionEndEvent, TransitionCancelEvent,
-		return result(view.setTransitionListener(tag, value))
+		AnimationStartEvent, AnimationEndEvent, AnimationIterationEvent, AnimationCancelEvent:
-
+		return setViewEventListener[View, string](view, tag, value)
-	case AnimationStartEvent, AnimationEndEvent, AnimationIterationEvent, AnimationCancelEvent:
+		//return setTransitionListener(view, tag, value), tag
-		return result(view.setAnimationListener(tag, value))
+		//return setAnimationListener(view, tag, value), tag
 
 	case ResizeEvent, ScrollEvent:
-		return result(view.setFrameListener(tag, value))
+		return setViewEventListener[View, Frame](view, tag, value)
-
+		//return setFrameListener(view, tag, value), tag
-	default:
-		if !view.viewStyle.set(tag, value) {
-			return false
-		}
-		if view.created {
-			viewPropertyChanged(view, tag)
-		}
 	}
 
-	view.propertyChangedEvent(tag)
+	return viewStyleSet(view, tag, value)
-	return true
 }
 
 func (view *viewData) SetParams(params Params) bool {
@@ -446,15 +439,29 @@ func (view *viewData) SetParams(params Params) bool {
 	return result
 }
 
-func viewPropertyChanged(view *viewData, tag string) {
+func viewPropertyChanged(view View, tag PropertyName) {
+	/*
 		if view.updateTransformProperty(tag) {
 			return
 		}
+	*/
 
 	htmlID := view.htmlID()
-	session := view.session
+	session := view.Session()
 
 	switch tag {
+	case TabIndex:
+		if value, ok := intProperty(view, TabIndex, view.Session(), 0); ok {
+			session.updateProperty(view.htmlID(), "tabindex", strconv.Itoa(value))
+		} else if view.Focusable() {
+			session.updateProperty(view.htmlID(), "tabindex", "0")
+		} else {
+			session.updateProperty(view.htmlID(), "tabindex", "-1")
+		}
+
+	case Style, StyleDisabled:
+		session.updateProperty(view.htmlID(), "class", view.htmlClass(IsDisabled(view)))
+
 	case Disabled:
 		tabIndex := GetTabIndex(view, htmlID)
 		enabledClass := view.htmlClass(false)
@@ -462,7 +469,7 @@ func viewPropertyChanged(view *viewData, tag string) {
 		session.startUpdateScript(htmlID)
 		if IsDisabled(view) {
 			session.updateProperty(htmlID, "data-disabled", "1")
-			if view.hasHtmlDisabled {
+			if view.htmlDisabledProperty() {
 				session.updateProperty(htmlID, "disabled", true)
 			}
 			if tabIndex >= 0 {
@@ -473,7 +480,7 @@ func viewPropertyChanged(view *viewData, tag string) {
 			}
 		} else {
 			session.updateProperty(htmlID, "data-disabled", "0")
-			if view.hasHtmlDisabled {
+			if view.htmlDisabledProperty() {
 				session.removeProperty(htmlID, "disabled")
 			}
 			if tabIndex >= 0 {
@@ -485,82 +492,65 @@ func viewPropertyChanged(view *viewData, tag string) {
 		}
 		session.finishUpdateScript(htmlID)
 		updateInnerHTML(htmlID, session)
-		return
 
 	case Visibility:
 		switch GetVisibility(view) {
 		case Invisible:
-			session.updateCSSProperty(htmlID, Visibility, "hidden")
+			session.updateCSSProperty(htmlID, string(Visibility), "hidden")
 			session.updateCSSProperty(htmlID, "display", "")
 			session.callFunc("hideTooltip")
 
 		case Gone:
-			session.updateCSSProperty(htmlID, Visibility, "hidden")
+			session.updateCSSProperty(htmlID, string(Visibility), "hidden")
 			session.updateCSSProperty(htmlID, "display", "none")
 			session.callFunc("hideTooltip")
 
 		default:
-			session.updateCSSProperty(htmlID, Visibility, "visible")
+			session.updateCSSProperty(htmlID, string(Visibility), "visible")
 			session.updateCSSProperty(htmlID, "display", "")
 		}
-		return
 
 	case Background:
-		session.updateCSSProperty(htmlID, Background, view.backgroundCSS(session))
+		session.updateCSSProperty(htmlID, string(Background), backgroundCSS(view, session))
-		return
 
-	case Border:
+	case Border, BorderLeft, BorderRight, BorderTop, BorderBottom:
-		if getBorder(view, Border) == nil {
+		cssWidth := ""
-			if session.startUpdateScript(htmlID) {
+		cssColor := ""
-				defer session.finishUpdateScript(htmlID)
+		cssStyle := "none"
-			}
-			session.updateCSSProperty(htmlID, BorderWidth, "")
-			session.updateCSSProperty(htmlID, BorderColor, "")
-			session.updateCSSProperty(htmlID, BorderStyle, "none")
-			return
-		}
-		fallthrough
 
-	case BorderLeft, BorderRight, BorderTop, BorderBottom:
+		if border := getBorderProperty(view, Border); border != nil {
-		if border := getBorder(view, Border); border != nil {
+			cssWidth = border.cssWidthValue(session)
-			if session.startUpdateScript(htmlID) {
+			cssColor = border.cssColorValue(session)
-				defer session.finishUpdateScript(htmlID)
+			cssStyle = border.cssStyleValue(session)
 		}
-			session.updateCSSProperty(htmlID, BorderWidth, border.cssWidthValue(session))
+
-			session.updateCSSProperty(htmlID, BorderColor, border.cssColorValue(session))
+		session.updateCSSProperty(htmlID, string(BorderWidth), cssWidth)
-			session.updateCSSProperty(htmlID, BorderStyle, border.cssStyleValue(session))
+		session.updateCSSProperty(htmlID, string(BorderColor), cssColor)
-		}
+		session.updateCSSProperty(htmlID, string(BorderStyle), cssStyle)
-		return
 
 	case BorderStyle, BorderLeftStyle, BorderRightStyle, BorderTopStyle, BorderBottomStyle:
-		if border := getBorder(view, Border); border != nil {
+		if border := getBorderProperty(view, Border); border != nil {
-			session.updateCSSProperty(htmlID, BorderStyle, border.cssStyleValue(session))
+			session.updateCSSProperty(htmlID, string(BorderStyle), border.cssStyleValue(session))
 		}
-		return
 
 	case BorderColor, BorderLeftColor, BorderRightColor, BorderTopColor, BorderBottomColor:
-		if border := getBorder(view, Border); border != nil {
+		if border := getBorderProperty(view, Border); border != nil {
-			session.updateCSSProperty(htmlID, BorderColor, border.cssColorValue(session))
+			session.updateCSSProperty(htmlID, string(BorderColor), border.cssColorValue(session))
 		}
-		return
 
 	case BorderWidth, BorderLeftWidth, BorderRightWidth, BorderTopWidth, BorderBottomWidth:
-		if border := getBorder(view, Border); border != nil {
+		if border := getBorderProperty(view, Border); border != nil {
-			session.updateCSSProperty(htmlID, BorderWidth, border.cssWidthValue(session))
+			session.updateCSSProperty(htmlID, string(BorderWidth), border.cssWidthValue(session))
 		}
-		return
 
 	case Outline, OutlineColor, OutlineStyle, OutlineWidth:
-		session.updateCSSProperty(htmlID, Outline, GetOutline(view).cssString(session))
+		session.updateCSSProperty(htmlID, string(Outline), GetOutline(view).cssString(session))
-		return
 
 	case Shadow:
 		session.updateCSSProperty(htmlID, "box-shadow", shadowCSS(view, Shadow, session))
-		return
 
 	case TextShadow:
 		session.updateCSSProperty(htmlID, "text-shadow", shadowCSS(view, TextShadow, session))
-		return
 
 	case Radius, RadiusX, RadiusY, RadiusTopLeft, RadiusTopLeftX, RadiusTopLeftY,
 		RadiusTopRight, RadiusTopRightX, RadiusTopRightY,
@@ -568,19 +558,16 @@ func viewPropertyChanged(view *viewData, tag string) {
 		RadiusBottomRight, RadiusBottomRightX, RadiusBottomRightY:
 		radius := GetRadius(view)
 		session.updateCSSProperty(htmlID, "border-radius", radius.cssString(session))
-		return
 
 	case Margin, MarginTop, MarginRight, MarginBottom, MarginLeft,
 		"top-margin", "right-margin", "bottom-margin", "left-margin":
 		margin := GetMargin(view)
-		session.updateCSSProperty(htmlID, Margin, margin.cssString(session))
+		session.updateCSSProperty(htmlID, string(Margin), margin.cssString(session))
-		return
 
 	case Padding, PaddingTop, PaddingRight, PaddingBottom, PaddingLeft,
 		"top-padding", "right-padding", "bottom-padding", "left-padding":
 		padding := GetPadding(view)
-		session.updateCSSProperty(htmlID, Padding, padding.cssString(session))
+		session.updateCSSProperty(htmlID, string(Padding), padding.cssString(session))
-		return
 
 	case AvoidBreak:
 		if avoid, ok := boolProperty(view, AvoidBreak, session); ok {
@@ -590,7 +577,6 @@ func viewPropertyChanged(view *viewData, tag string) {
 				session.updateCSSProperty(htmlID, "break-inside", "auto")
 			}
 		}
-		return
 
 	case Clip:
 		if clip := getClipShape(view, Clip, session); clip != nil && clip.valid(session) {
@@ -598,29 +584,26 @@ func viewPropertyChanged(view *viewData, tag string) {
 		} else {
 			session.updateCSSProperty(htmlID, `clip-path`, "none")
 		}
-		return
 
 	case ShapeOutside:
 		if clip := getClipShape(view, ShapeOutside, session); clip != nil && clip.valid(session) {
-			session.updateCSSProperty(htmlID, ShapeOutside, clip.cssStyle(session))
+			session.updateCSSProperty(htmlID, string(ShapeOutside), clip.cssStyle(session))
 		} else {
-			session.updateCSSProperty(htmlID, ShapeOutside, "none")
+			session.updateCSSProperty(htmlID, string(ShapeOutside), "none")
 		}
-		return
 
 	case Filter:
 		text := ""
-		if value := view.getRaw(tag); value != nil {
+		if value := view.getRaw(Filter); value != nil {
 			if filter, ok := value.(ViewFilter); ok {
 				text = filter.cssStyle(session)
 			}
 		}
-		session.updateCSSProperty(htmlID, tag, text)
+		session.updateCSSProperty(htmlID, string(Filter), text)
-		return
 
 	case BackdropFilter:
 		text := ""
-		if value := view.getRaw(tag); value != nil {
+		if value := view.getRaw(BackdropFilter); value != nil {
 			if filter, ok := value.(ViewFilter); ok {
 				text = filter.cssStyle(session)
 			}
@@ -629,8 +612,7 @@ func viewPropertyChanged(view *viewData, tag string) {
 			defer session.finishUpdateScript(htmlID)
 		}
 		session.updateCSSProperty(htmlID, "-webkit-backdrop-filter", text)
-		session.updateCSSProperty(htmlID, tag, text)
+		session.updateCSSProperty(htmlID, string(BackdropFilter), text)
-		return
 
 	case FontName:
 		if font, ok := stringProperty(view, FontName, session); ok {
@@ -638,7 +620,6 @@ func viewPropertyChanged(view *viewData, tag string) {
 		} else {
 			session.updateCSSProperty(htmlID, "font-family", "")
 		}
-		return
 
 	case Italic:
 		if state, ok := boolProperty(view, tag, session); ok {
@@ -650,7 +631,6 @@ func viewPropertyChanged(view *viewData, tag string) {
 		} else {
 			session.updateCSSProperty(htmlID, "font-style", "")
 		}
-		return
 
 	case SmallCaps:
 		if state, ok := boolProperty(view, tag, session); ok {
@@ -662,22 +642,18 @@ func viewPropertyChanged(view *viewData, tag string) {
 		} else {
 			session.updateCSSProperty(htmlID, "font-variant", "")
 		}
-		return
 
 	case Strikethrough, Overline, Underline:
-		session.updateCSSProperty(htmlID, "text-decoration", view.cssTextDecoration(session))
+		session.updateCSSProperty(htmlID, "text-decoration", textDecorationCSS(view, session))
-		for _, tag2 := range []string{TextLineColor, TextLineStyle, TextLineThickness} {
+		for _, tag2 := range []PropertyName{TextLineColor, TextLineStyle, TextLineThickness} {
 			viewPropertyChanged(view, tag2)
 		}
-		return
 
 	case Transition:
-		view.updateTransitionCSS()
+		session.updateCSSProperty(htmlID, "transition", transitionCSS(view, session))
-		return
 
 	case AnimationTag:
-		session.updateCSSProperty(htmlID, AnimationTag, view.animationCSS(session))
+		session.updateCSSProperty(htmlID, "animation", animationCSS(view, session))
-		return
 
 	case AnimationPaused:
 		paused, ok := boolProperty(view, AnimationPaused, session)
@@ -688,21 +664,18 @@ func viewPropertyChanged(view *viewData, tag string) {
 		} else {
 			session.updateCSSProperty(htmlID, `animation-play-state`, `running`)
 		}
-		return
 
 	case ZIndex, Order, TabSize:
 		if i, ok := intProperty(view, tag, session, 0); ok {
-			session.updateCSSProperty(htmlID, tag, strconv.Itoa(i))
+			session.updateCSSProperty(htmlID, string(tag), strconv.Itoa(i))
 		} else {
-			session.updateCSSProperty(htmlID, tag, "")
+			session.updateCSSProperty(htmlID, string(tag), "")
 		}
-		return
 
 	case Row, Column:
 		if parentID := view.parentHTMLID(); parentID != "" {
 			updateInnerHTML(parentID, session)
 		}
-		return
 
 	case UserSelect:
 		if session.startUpdateScript(htmlID) {
@@ -720,7 +693,6 @@ func viewPropertyChanged(view *viewData, tag string) {
 			session.updateCSSProperty(htmlID, "-webkit-user-select", "")
 			session.updateCSSProperty(htmlID, "user-select", "")
 		}
-		return
 
 	case ColumnSpanAll:
 		if spanAll, ok := boolProperty(view, ColumnSpanAll, session); ok && spanAll {
@@ -728,7 +700,6 @@ func viewPropertyChanged(view *viewData, tag string) {
 		} else {
 			session.updateCSSProperty(htmlID, `column-span`, `none`)
 		}
-		return
 
 	case Tooltip:
 		if tooltip := GetTooltip(view); tooltip == "" {
@@ -738,9 +709,58 @@ func viewPropertyChanged(view *viewData, tag string) {
 			session.updateProperty(htmlID, "onmouseenter", "mouseEnterEvent(this, event)")
 			session.updateProperty(htmlID, "onmouseleave", "mouseLeaveEvent(this, event)")
 		}
-		return
+
+	case PerspectiveOriginX, PerspectiveOriginY:
+		if getTransform3D(view, session) {
+			x, y := GetPerspectiveOrigin(view)
+			value := ""
+			if x.Type != Auto || y.Type != Auto {
+				value = x.cssString("50%", session) + " " + y.cssString("50%", session)
+			}
+			session.updateCSSProperty(htmlID, "perspective-origin", value)
 		}
 
+	case BackfaceVisible:
+		if getTransform3D(view, session) {
+			if GetBackfaceVisible(view) {
+				session.updateCSSProperty(htmlID, string(BackfaceVisible), "visible")
+			} else {
+				session.updateCSSProperty(htmlID, string(BackfaceVisible), "hidden")
+			}
+		}
+
+	case OriginX, OriginY, OriginZ:
+		x, y, z := getOrigin(view, session)
+		value := ""
+
+		if z.Type != Auto {
+			value = x.cssString("50%", session) + " " + y.cssString("50%", session) + " " + z.cssString("50%", session)
+		} else if x.Type != Auto || y.Type != Auto {
+			value = x.cssString("50%", session) + " " + y.cssString("50%", session)
+		}
+		session.updateCSSProperty(htmlID, "transform-origin", value)
+
+	case TransformTag, Perspective, SkewX, SkewY, TranslateX, TranslateY, TranslateZ,
+		ScaleX, ScaleY, ScaleZ, Rotate, RotateX, RotateY, RotateZ:
+		css := ""
+		if transform := getTransformProperty(view); transform != nil {
+			css = transform.transformCSS(session)
+		}
+		session.updateCSSProperty(htmlID, "transform", css)
+
+	case FocusEvent, LostFocusEvent, ResizeEvent, ScrollEvent, KeyDownEvent, KeyUpEvent,
+		ClickEvent, DoubleClickEvent, MouseDown, MouseUp, MouseMove, MouseOut, MouseOver, ContextMenuEvent,
+		PointerDown, PointerUp, PointerMove, PointerOut, PointerOver, PointerCancel,
+		TouchStart, TouchEnd, TouchMove, TouchCancel,
+		TransitionRunEvent, TransitionStartEvent, TransitionEndEvent, TransitionCancelEvent,
+		AnimationStartEvent, AnimationEndEvent, AnimationIterationEvent, AnimationCancelEvent:
+
+		updateEventListenerHtml(view, tag)
+
+	case DataList:
+		updateInnerHTML(view.htmlID(), view.Session())
+
+	default:
 		if cssTag, ok := sizeProperties[tag]; ok {
 			if size, ok := sizeProperty(view, tag, session); ok {
 				session.updateCSSProperty(htmlID, cssTag, size.cssString("", session))
@@ -750,12 +770,12 @@ func viewPropertyChanged(view *viewData, tag string) {
 			return
 		}
 
-	colorTags := map[string]string{
+		colorTags := map[PropertyName]string{
-		BackgroundColor: BackgroundColor,
+			BackgroundColor: string(BackgroundColor),
 			TextColor:       "color",
 			TextLineColor:   "text-decoration-color",
-		CaretColor:      CaretColor,
+			CaretColor:      string(CaretColor),
-		AccentColor:     AccentColor,
+			AccentColor:     string(AccentColor),
 		}
 		if cssTag, ok := colorTags[tag]; ok {
 			if color, ok := colorProperty(view, tag, session); ok {
@@ -775,31 +795,23 @@ func viewPropertyChanged(view *viewData, tag string) {
 			return
 		}
 
-	for _, floatTag := range []string{Opacity, ScaleX, ScaleY, ScaleZ, RotateX, RotateY, RotateZ} {
+		if f, ok := floatTextProperty(view, Opacity, session, 0); ok {
-		if tag == floatTag {
+			session.updateCSSProperty(htmlID, string(Opacity), f)
-			if f, ok := floatTextProperty(view, floatTag, session, 0); ok {
-				session.updateCSSProperty(htmlID, floatTag, f)
 		} else {
-				session.updateCSSProperty(htmlID, floatTag, "")
+			session.updateCSSProperty(htmlID, string(Opacity), "")
-			}
-			return
 		}
 	}
 }
 
-func (view *viewData) Get(tag string) any {
+func viewGet(view View, tag PropertyName) any {
-	return view.get(strings.ToLower(tag))
-}
-
-func (view *viewData) get(tag string) any {
 	if tag == ID {
-		if view.viewID != "" {
+		if id := view.ID(); id != "" {
-			return view.viewID
+			return id
 		} else {
 			return nil
 		}
 	}
-	return view.viewStyle.get(tag)
+	return viewStyleGet(view, tag)
 }
 
 func (view *viewData) htmlTag() string {
@@ -848,6 +860,10 @@ func (view *viewData) cssStyle(self View, builder cssBuilder) {
 	}
 }
 
+func (view *viewData) htmlDisabledProperty() bool {
+	return view.hasHtmlDisabled
+}
+
 func (view *viewData) htmlProperties(self View, buffer *strings.Builder) {
 	view.created = true
 
@@ -908,23 +924,30 @@ func viewHTML(view View, buffer *strings.Builder) {
 		}
 	}
 
-	hasTooltip := false
 	if tooltip := GetTooltip(view); tooltip != "" {
 		buffer.WriteString(`data-tooltip=" `)
 		buffer.WriteString(tooltip)
-		buffer.WriteString(`" `)
+		buffer.WriteString(`" onmouseenter="mouseEnterEvent(this, event)" onmouseleave="mouseLeaveEvent(this, event)" `)
-		hasTooltip = true
 	}
 
 	buffer.WriteString(`onscroll="scrollEvent(this, event)" `)
 
-	keyEventsHtml(view, buffer)
-	mouseEventsHtml(view, buffer, hasTooltip)
-	pointerEventsHtml(view, buffer)
-	touchEventsHtml(view, buffer)
 	focusEventsHtml(view, buffer)
-	transitionEventsHtml(view, buffer)
+	keyEventsHtml(view, buffer)
-	animationEventsHtml(view, buffer)
+
+	viewEventsHtml[MouseEvent](view, []PropertyName{ClickEvent, DoubleClickEvent, MouseDown, MouseUp, MouseMove, MouseOut, MouseOver, ContextMenuEvent}, buffer)
+	//mouseEventsHtml(view, buffer, hasTooltip)
+
+	viewEventsHtml[PointerEvent](view, []PropertyName{PointerDown, PointerUp, PointerMove, PointerOut, PointerOver, PointerCancel}, buffer)
+	//pointerEventsHtml(view, buffer)
+
+	viewEventsHtml[TouchEvent](view, []PropertyName{TouchStart, TouchEnd, TouchMove, TouchCancel}, buffer)
+	//touchEventsHtml(view, buffer)
+
+	viewEventsHtml[string](view, []PropertyName{TransitionRunEvent, TransitionStartEvent, TransitionEndEvent, TransitionCancelEvent,
+		AnimationStartEvent, AnimationEndEvent, AnimationIterationEvent, AnimationCancelEvent}, buffer)
+	//transitionEventsHtml(view, buffer)
+	//animationEventsHtml(view, buffer)
 
 	buffer.WriteRune('>')
 	view.htmlSubviews(view, buffer)
@@ -957,7 +980,7 @@ func (view *viewData) htmlClass(disabled bool) string {
 	return cls
 }
 
-func (view *viewData) handleCommand(self View, command string, data DataObject) bool {
+func (view *viewData) handleCommand(self View, command PropertyName, data DataObject) bool {
 	switch command {
 
 	case KeyDownEvent, KeyUpEvent:
@@ -976,13 +999,13 @@ func (view *viewData) handleCommand(self View, command string, data DataObject)
 
 	case FocusEvent:
 		view.hasFocus = true
-		for _, listener := range getFocusListeners(view, nil, command) {
+		for _, listener := range getNoParamEventListeners[View](view, nil, command) {
 			listener(self)
 		}
 
 	case LostFocusEvent:
 		view.hasFocus = false
-		for _, listener := range getFocusListeners(view, nil, command) {
+		for _, listener := range getNoParamEventListeners[View](view, nil, command) {
 			listener(self)
 		}
 
@@ -1030,7 +1053,7 @@ func (view *viewData) handleCommand(self View, command string, data DataObject)
 
 }
 
-func (view *viewData) SetChangeListener(tag string, listener func(View, string)) {
+func (view *viewData) SetChangeListener(tag PropertyName, listener func(View, PropertyName)) {
 	if listener == nil {
 		delete(view.changeListener, tag)
 	} else {
@@ -1043,9 +1066,12 @@ func (view *viewData) HasFocus() bool {
 }
 
 func (view *viewData) String() string {
-	return getViewString(view, nil)
+	buffer := allocStringBuilder()
+	defer freeStringBuilder(buffer)
+	writeViewStyle(view.tag, view, buffer, "", nil)
+	return buffer.String()
 }
 
-func (view *viewData) exscludeTags() []string {
+func (view *viewData) exscludeTags() []PropertyName {
 	return nil
 }

viewClip.go

@@ -15,19 +15,19 @@ type ClipShape interface {
 }
 
 type insetClip struct {
-	propertyList
+	dataProperty
 }
 
 type ellipseClip struct {
-	propertyList
+	dataProperty
 }
 
 type circleClip struct {
-	propertyList
+	dataProperty
 }
 
 type polygonClip struct {
-	points []any
+	dataProperty
 }
 
 // InsetClip creates a rectangle View clipping area.
@@ -39,12 +39,12 @@ type polygonClip struct {
 func InsetClip(top, right, bottom, left SizeUnit, radius RadiusProperty) ClipShape {
 	clip := new(insetClip)
 	clip.init()
-	clip.Set(Top, top)
+	clip.setRaw(Top, top)
-	clip.Set(Right, right)
+	clip.setRaw(Right, right)
-	clip.Set(Bottom, bottom)
+	clip.setRaw(Bottom, bottom)
-	clip.Set(Left, left)
+	clip.setRaw(Left, left)
 	if radius != nil {
-		clip.Set(Radius, radius)
+		clip.setRaw(Radius, radius)
 	}
 	return clip
 }
@@ -53,9 +53,9 @@ func InsetClip(top, right, bottom, left SizeUnit, radius RadiusProperty) ClipSha
 func CircleClip(x, y, radius SizeUnit) ClipShape {
 	clip := new(circleClip)
 	clip.init()
-	clip.Set(X, x)
+	clip.setRaw(X, x)
-	clip.Set(Y, y)
+	clip.setRaw(Y, y)
-	clip.Set(Radius, radius)
+	clip.setRaw(Radius, radius)
 	return clip
 }
 
@@ -63,10 +63,10 @@ func CircleClip(x, y, radius SizeUnit) ClipShape {
 func EllipseClip(x, y, rx, ry SizeUnit) ClipShape {
 	clip := new(ellipseClip)
 	clip.init()
-	clip.Set(X, x)
+	clip.setRaw(X, x)
-	clip.Set(Y, y)
+	clip.setRaw(Y, y)
-	clip.Set(RadiusX, rx)
+	clip.setRaw(RadiusX, rx)
-	clip.Set(RadiusY, ry)
+	clip.setRaw(RadiusY, ry)
 	return clip
 }
 
@@ -75,8 +75,8 @@ func EllipseClip(x, y, rx, ry SizeUnit) ClipShape {
 // or the text representation of SizeUnit, or elements of SizeUnit type.
 func PolygonClip(points []any) ClipShape {
 	clip := new(polygonClip)
-	clip.points = []any{}
+	clip.init()
-	if clip.Set(Points, points) {
+	if polygonClipSet(clip, Points, points) != nil {
 		return clip
 	}
 	return nil
@@ -85,34 +85,45 @@ func PolygonClip(points []any) ClipShape {
 // PolygonPointsClip creates a polygon View clipping area.
 func PolygonPointsClip(points []SizeUnit) ClipShape {
 	clip := new(polygonClip)
-	clip.points = []any{}
+	clip.init()
-	if clip.Set(Points, points) {
+	if polygonClipSet(clip, Points, points) != nil {
 		return clip
 	}
 	return nil
 }
 
-func (clip *insetClip) Set(tag string, value any) bool {
+func (clip *insetClip) init() {
-	switch strings.ToLower(tag) {
+	clip.dataProperty.init()
-	case Top, Right, Bottom, Left:
+	clip.set = insetClipSet
-		if value == nil {
+	clip.supportedProperties = []PropertyName{
-			clip.Remove(tag)
+		Top, Right, Bottom, Left, Radius,
-			return true
+		RadiusX, RadiusY, RadiusTopLeft, RadiusTopLeftX, RadiusTopLeftY,
+		RadiusTopRight, RadiusTopRightX, RadiusTopRightY,
+		RadiusBottomLeft, RadiusBottomLeftX, RadiusBottomLeftY,
+		RadiusBottomRight, RadiusBottomRightX, RadiusBottomRightY,
 	}
-		return clip.setSizeProperty(tag, value)
+}
+
+func insetClipSet(properties Properties, tag PropertyName, value any) []PropertyName {
+	switch tag {
+	case Top, Right, Bottom, Left:
+		return setSizeProperty(properties, tag, value)
 
 	case Radius:
-		return clip.setRadius(value)
+		return setRadiusProperty(properties, value)
 
 	case RadiusX, RadiusY, RadiusTopLeft, RadiusTopLeftX, RadiusTopLeftY,
 		RadiusTopRight, RadiusTopRightX, RadiusTopRightY,
 		RadiusBottomLeft, RadiusBottomLeftX, RadiusBottomLeftY,
 		RadiusBottomRight, RadiusBottomRightX, RadiusBottomRightY:
-		return clip.setRadiusElement(tag, value)
+		if setRadiusPropertyElement(properties, tag, value) {
+			return []PropertyName{tag, Radius}
+		}
+		return nil
 	}
 
 	ErrorLogF(`"%s" property is not supported by the inset clip shape`, tag)
-	return false
+	return nil
 }
 
 func (clip *insetClip) String() string {
@@ -122,12 +133,12 @@ func (clip *insetClip) String() string {
 func (clip *insetClip) writeString(buffer *strings.Builder, indent string) {
 	buffer.WriteString("inset { ")
 	comma := false
-	for _, tag := range []string{Top, Right, Bottom, Left, Radius} {
+	for _, tag := range []PropertyName{Top, Right, Bottom, Left, Radius} {
 		if value, ok := clip.properties[tag]; ok {
 			if comma {
 				buffer.WriteString(", ")
 			}
-			buffer.WriteString(tag)
+			buffer.WriteString(string(tag))
 			buffer.WriteString(" = ")
 			writePropertyValue(buffer, tag, value, indent)
 			comma = true
@@ -143,7 +154,7 @@ func (clip *insetClip) cssStyle(session Session) string {
 	defer freeStringBuilder(buffer)
 
 	leadText := "inset("
-	for _, tag := range []string{Top, Right, Bottom, Left} {
+	for _, tag := range []PropertyName{Top, Right, Bottom, Left} {
 		value, _ := sizeProperty(clip, tag, session)
 		buffer.WriteString(leadText)
 		buffer.WriteString(value.cssString("0px", session))
@@ -160,7 +171,7 @@ func (clip *insetClip) cssStyle(session Session) string {
 }
 
 func (clip *insetClip) valid(session Session) bool {
-	for _, tag := range []string{Top, Right, Bottom, Left, Radius, RadiusX, RadiusY} {
+	for _, tag := range []PropertyName{Top, Right, Bottom, Left, Radius, RadiusX, RadiusY} {
 		if value, ok := sizeProperty(clip, tag, session); ok && value.Type != Auto && value.Value != 0 {
 			return true
 		}
@@ -168,18 +179,20 @@ func (clip *insetClip) valid(session Session) bool {
 	return false
 }
 
-func (clip *circleClip) Set(tag string, value any) bool {
+func (clip *circleClip) init() {
-	if value == nil {
+	clip.dataProperty.init()
-		clip.Remove(tag)
+	clip.set = circleClipSet
+	clip.supportedProperties = []PropertyName{X, Y, Radius}
 }
 
-	switch strings.ToLower(tag) {
+func circleClipSet(properties Properties, tag PropertyName, value any) []PropertyName {
+	switch tag {
 	case X, Y, Radius:
-		return clip.setSizeProperty(tag, value)
+		return setSizeProperty(properties, tag, value)
 	}
 
 	ErrorLogF(`"%s" property is not supported by the circle clip shape`, tag)
-	return false
+	return nil
 }
 
 func (clip *circleClip) String() string {
@@ -189,12 +202,12 @@ func (clip *circleClip) String() string {
 func (clip *circleClip) writeString(buffer *strings.Builder, indent string) {
 	buffer.WriteString("circle { ")
 	comma := false
-	for _, tag := range []string{Radius, X, Y} {
+	for _, tag := range []PropertyName{Radius, X, Y} {
 		if value, ok := clip.properties[tag]; ok {
 			if comma {
 				buffer.WriteString(", ")
 			}
-			buffer.WriteString(tag)
+			buffer.WriteString(string(tag))
 			buffer.WriteString(" = ")
 			writePropertyValue(buffer, tag, value, indent)
 			comma = true
@@ -232,22 +245,27 @@ func (clip *circleClip) valid(session Session) bool {
 	return true
 }
 
-func (clip *ellipseClip) Set(tag string, value any) bool {
+func (clip *ellipseClip) init() {
-	if value == nil {
+	clip.dataProperty.init()
-		clip.Remove(tag)
+	clip.set = ellipseClipSet
+	clip.supportedProperties = []PropertyName{X, Y, Radius, RadiusX, RadiusY}
 }
 
-	switch strings.ToLower(tag) {
+func ellipseClipSet(properties Properties, tag PropertyName, value any) []PropertyName {
+	switch tag {
 	case X, Y, RadiusX, RadiusY:
-		return clip.setSizeProperty(tag, value)
+		return setSizeProperty(properties, tag, value)
 
 	case Radius:
-		return clip.setSizeProperty(RadiusX, value) &&
+		if result := setSizeProperty(properties, RadiusX, value); result != nil {
-			clip.setSizeProperty(RadiusY, value)
+			properties.setRaw(RadiusY, properties.getRaw(RadiusX))
+			return append(result, RadiusY)
+		}
+		return nil
 	}
 
 	ErrorLogF(`"%s" property is not supported by the ellipse clip shape`, tag)
-	return false
+	return nil
 }
 
 func (clip *ellipseClip) String() string {
@@ -257,12 +275,12 @@ func (clip *ellipseClip) String() string {
 func (clip *ellipseClip) writeString(buffer *strings.Builder, indent string) {
 	buffer.WriteString("ellipse { ")
 	comma := false
-	for _, tag := range []string{RadiusX, RadiusY, X, Y} {
+	for _, tag := range []PropertyName{RadiusX, RadiusY, X, Y} {
 		if value, ok := clip.properties[tag]; ok {
 			if comma {
 				buffer.WriteString(", ")
 			}
-			buffer.WriteString(tag)
+			buffer.WriteString(string(tag))
 			buffer.WriteString(" = ")
 			writePropertyValue(buffer, tag, value, indent)
 			comma = true
@@ -302,104 +320,91 @@ func (clip *ellipseClip) valid(session Session) bool {
 	return rx.Value != 0 && ry.Value != 0
 }
 
-func (clip *polygonClip) Get(tag string) any {
+func (clip *polygonClip) init() {
-	if Points == strings.ToLower(tag) {
+	clip.dataProperty.init()
-		return clip.points
+	clip.set = polygonClipSet
-	}
+	clip.supportedProperties = []PropertyName{Points}
-	return nil
 }
 
-func (clip *polygonClip) getRaw(tag string) any {
+func polygonClipSet(properties Properties, tag PropertyName, value any) []PropertyName {
-	return clip.Get(tag)
+	if Points == tag {
-}
-
-func (clip *polygonClip) Set(tag string, value any) bool {
-	if Points == strings.ToLower(tag) {
 		switch value := value.(type) {
 		case []any:
-			result := true
+			points := make([]any, len(value))
-			clip.points = make([]any, len(value))
 			for i, val := range value {
 				switch val := val.(type) {
 				case string:
 					if isConstantName(val) {
-						clip.points[i] = val
+						points[i] = val
 					} else if size, ok := StringToSizeUnit(val); ok {
-						clip.points[i] = size
+						points[i] = size
 					} else {
 						notCompatibleType(tag, val)
-						result = false
+						return nil
 					}
 
 				case SizeUnit:
-					clip.points[i] = val
+					points[i] = val
 
 				default:
 					notCompatibleType(tag, val)
-					clip.points[i] = AutoSize()
+					points[i] = AutoSize()
-					result = false
+					return nil
 				}
 			}
-			return result
+			properties.setRaw(Points, points)
+			return []PropertyName{tag}
 
 		case []SizeUnit:
-			clip.points = make([]any, len(value))
+			points := make([]any, len(value))
 			for i, point := range value {
-				clip.points[i] = point
+				points[i] = point
 			}
-			return true
+			properties.setRaw(Points, points)
+			return []PropertyName{tag}
 
 		case string:
-			result := true
 			values := strings.Split(value, ",")
-			clip.points = make([]any, len(values))
+			points := make([]any, len(values))
 			for i, val := range values {
 				val = strings.Trim(val, " \t\n\r")
 				if isConstantName(val) {
-					clip.points[i] = val
+					points[i] = val
 				} else if size, ok := StringToSizeUnit(val); ok {
-					clip.points[i] = size
+					points[i] = size
 				} else {
 					notCompatibleType(tag, val)
-					result = false
+					return nil
 				}
 			}
-			return result
+			properties.setRaw(Points, points)
+			return []PropertyName{tag}
 		}
 	}
-	return false
+	return nil
-}
-
-func (clip *polygonClip) setRaw(tag string, value any) {
-	clip.Set(tag, value)
-}
-
-func (clip *polygonClip) Remove(tag string) {
-	if Points == strings.ToLower(tag) {
-		clip.points = []any{}
-	}
-}
-
-func (clip *polygonClip) Clear() {
-	clip.points = []any{}
-}
-
-func (clip *polygonClip) AllTags() []string {
-	return []string{Points}
 }
 
 func (clip *polygonClip) String() string {
 	return runStringWriter(clip)
 }
 
+func (clip *polygonClip) points() []any {
+	if value := clip.getRaw(Points); value != nil {
+		if points, ok := value.([]any); ok {
+			return points
+		}
+	}
+	return nil
+}
+
 func (clip *polygonClip) writeString(buffer *strings.Builder, indent string) {
 
 	buffer.WriteString("inset { ")
 
-	if clip.points != nil {
+	if points := clip.points(); points != nil {
-		buffer.WriteString(Points)
+		buffer.WriteString(string(Points))
 		buffer.WriteString(` = "`)
-		for i, value := range clip.points {
+		for i, value := range points {
 			if i > 0 {
 				buffer.WriteString(", ")
 			}
@@ -408,13 +413,13 @@ func (clip *polygonClip) writeString(buffer *strings.Builder, indent string) {
 
 		buffer.WriteString(`" `)
 	}
-
 	buffer.WriteRune('}')
 }
 
 func (clip *polygonClip) cssStyle(session Session) string {
 
-	count := len(clip.points)
+	points := clip.points()
+	count := len(points)
 	if count < 2 {
 		return ""
 	}
@@ -443,9 +448,9 @@ func (clip *polygonClip) cssStyle(session Session) string {
 	leadText := "polygon("
 	for i := 1; i < count; i += 2 {
 		buffer.WriteString(leadText)
-		writePoint(clip.points[i-1])
+		writePoint(points[i-1])
 		buffer.WriteRune(' ')
-		writePoint(clip.points[i])
+		writePoint(points[i])
 		leadText = ", "
 	}
 
@@ -454,42 +459,46 @@ func (clip *polygonClip) cssStyle(session Session) string {
 }
 
 func (clip *polygonClip) valid(session Session) bool {
-	return len(clip.points) > 0
+	return len(clip.points()) > 0
 }
 
 func parseClipShape(obj DataObject) ClipShape {
 	switch obj.Tag() {
 	case "inset":
 		clip := new(insetClip)
-		for _, tag := range []string{Top, Right, Bottom, Left, Radius, RadiusX, RadiusY} {
+		clip.init()
-			if value, ok := obj.PropertyValue(tag); ok {
+		for _, tag := range []PropertyName{Top, Right, Bottom, Left, Radius, RadiusX, RadiusY} {
-				clip.Set(tag, value)
+			if value, ok := obj.PropertyValue(string(tag)); ok {
+				insetClipSet(clip, tag, value)
 			}
 		}
 		return clip
 
 	case "circle":
 		clip := new(ellipseClip)
-		for _, tag := range []string{X, Y, Radius} {
+		clip.init()
-			if value, ok := obj.PropertyValue(tag); ok {
+		for _, tag := range []PropertyName{X, Y, Radius} {
-				clip.Set(tag, value)
+			if value, ok := obj.PropertyValue(string(tag)); ok {
+				circleClipSet(clip, tag, value)
 			}
 		}
 		return clip
 
 	case "ellipse":
 		clip := new(ellipseClip)
-		for _, tag := range []string{X, Y, RadiusX, RadiusY} {
+		clip.init()
-			if value, ok := obj.PropertyValue(tag); ok {
+		for _, tag := range []PropertyName{X, Y, RadiusX, RadiusY} {
-				clip.Set(tag, value)
+			if value, ok := obj.PropertyValue(string(tag)); ok {
+				ellipseClipSet(clip, tag, value)
 			}
 		}
 		return clip
 
 	case "polygon":
 		clip := new(ellipseClip)
-		if value, ok := obj.PropertyValue(Points); ok {
+		clip.init()
-			clip.Set(Points, value)
+		if value, ok := obj.PropertyValue(string(Points)); ok {
+			polygonClipSet(clip, Points, value)
 		}
 		return clip
 	}
@@ -497,45 +506,45 @@ func parseClipShape(obj DataObject) ClipShape {
 	return nil
 }
 
-func (style *viewStyle) setClipShape(tag string, value any) bool {
+func setClipShapeProperty(properties Properties, tag PropertyName, value any) []PropertyName {
 	switch value := value.(type) {
 	case ClipShape:
-		style.properties[tag] = value
+		properties.setRaw(tag, value)
-		return true
+		return []PropertyName{tag}
 
 	case string:
 		if isConstantName(value) {
-			style.properties[tag] = value
+			properties.setRaw(tag, value)
-			return true
+			return []PropertyName{tag}
 		}
 
 		if obj := NewDataObject(value); obj == nil {
 			if clip := parseClipShape(obj); clip != nil {
-				style.properties[tag] = clip
+				properties.setRaw(tag, clip)
-				return true
+				return []PropertyName{tag}
 			}
 		}
 
 	case DataObject:
 		if clip := parseClipShape(value); clip != nil {
-			style.properties[tag] = clip
+			properties.setRaw(tag, clip)
-			return true
+			return []PropertyName{tag}
 		}
 
 	case DataValue:
 		if value.IsObject() {
 			if clip := parseClipShape(value.Object()); clip != nil {
-				style.properties[tag] = clip
+				properties.setRaw(tag, clip)
-				return true
+				return []PropertyName{tag}
 			}
 		}
 	}
 
 	notCompatibleType(tag, value)
-	return false
+	return nil
 }
 
-func getClipShape(prop Properties, tag string, session Session) ClipShape {
+func getClipShape(prop Properties, tag PropertyName, session Session) ClipShape {
 	if value := prop.getRaw(tag); value != nil {
 		switch value := value.(type) {
 		case ClipShape:

viewFactory.go

@@ -85,6 +85,7 @@ func CreateViewFromObject(session Session, object DataObject) View {
 			defer session.setIgnoreViewUpdates(false)
 		}
 		view := creator(session)
+		view.init(session)
 		if customView, ok := view.(CustomView); ok {
 			if !InitCustomView(customView, tag, session, nil) {
 				return nil

viewFilter.go

@@ -17,7 +17,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	Blur = "blur"
+	Blur PropertyName = "blur"
 
 	// Brightness is the constant for "brightness" property tag.
 	//
@@ -29,7 +29,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	Brightness = "brightness"
+	Brightness PropertyName = "brightness"
 
 	// Contrast is the constant for "contrast" property tag.
 	//
@@ -40,7 +40,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	Contrast = "contrast"
+	Contrast PropertyName = "contrast"
 
 	// DropShadow is the constant for "drop-shadow" property tag.
 	//
@@ -58,7 +58,7 @@ const (
 	// `[]ViewShadow` - stored as is, no conversion performed.
 	// `ViewShadow` - converted to `[]ViewShadow`.
 	// `string` - string representation of `ViewShadow`. Example: "_{blur = 1em, color = black, spread-radius = 0.5em}".
-	DropShadow = "drop-shadow"
+	DropShadow PropertyName = "drop-shadow"
 
 	// Grayscale is the constant for "grayscale" property tag.
 	//
@@ -70,7 +70,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	Grayscale = "grayscale"
+	Grayscale PropertyName = "grayscale"
 
 	// HueRotate is the constant for "hue-rotate" property tag.
 	//
@@ -89,7 +89,7 @@ const (
 	// `string` - must contain string representation of `AngleUnit`. If numeric value will be provided without any suffix then `AngleUnit` with value and `Radian` value type will be created.
 	// `float` - a new `AngleUnit` value will be created with `Radian` as a type.
 	// `int` - a new `AngleUnit` value will be created with `Radian` as a type.
-	HueRotate = "hue-rotate"
+	HueRotate PropertyName = "hue-rotate"
 
 	// Invert is the constant for "invert" property tag.
 	//
@@ -101,7 +101,7 @@ const (
 	// Supported types: `float64`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	Invert = "invert"
+	Invert PropertyName = "invert"
 
 	// Saturate is the constant for "saturate" property tag.
 	//
@@ -113,7 +113,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	Saturate = "saturate"
+	Saturate PropertyName = "saturate"
 
 	// Sepia is the constant for "sepia" property tag.
 	//
@@ -125,9 +125,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	Sepia = "sepia"
+	Sepia PropertyName = "sepia"
-
-	//Opacity = "opacity"
 )
 
 // ViewFilter defines an applied to a View a graphical effects like blur or color shift.
@@ -140,21 +138,21 @@ type ViewFilter interface {
 }
 
 type viewFilter struct {
-	propertyList
+	dataProperty
 }
 
 // NewViewFilter creates the new ViewFilter
 func NewViewFilter(params Params) ViewFilter {
-	if params != nil {
+	if len(params) > 0 {
 		filter := new(viewFilter)
 		filter.init()
 		for tag, value := range params {
-			filter.Set(tag, value)
+			if !filter.Set(tag, value) {
+				return nil
+			}
 		}
-		if len(filter.properties) > 0 {
 		return filter
 	}
-	}
 	return nil
 }
 
@@ -166,10 +164,10 @@ func newViewFilter(obj DataObject) ViewFilter {
 			tag := node.Tag()
 			switch node.Type() {
 			case TextNode:
-				filter.Set(tag, node.Text())
+				filter.Set(PropertyName(tag), node.Text())
 
 			case ObjectNode:
-				if tag == HueRotate {
+				if tag == string(HueRotate) {
 					// TODO
 				} else {
 					ErrorLog(`Invalid value of "` + tag + `"`)
@@ -188,28 +186,31 @@ func newViewFilter(obj DataObject) ViewFilter {
 	return nil
 }
 
-func (filter *viewFilter) Set(tag string, value any) bool {
+func (filter *viewFilter) init() {
-	if value == nil {
+	filter.dataProperty.init()
-		filter.Remove(tag)
+	filter.set = viewFilterSet
-		return true
+	filter.supportedProperties = []PropertyName{Blur, Brightness, Contrast, Saturate, Grayscale, Invert, Opacity, Sepia, HueRotate, DropShadow}
 }
 
-	switch strings.ToLower(tag) {
+func viewFilterSet(properties Properties, tag PropertyName, value any) []PropertyName {
+	switch tag {
 	case Blur, Brightness, Contrast, Saturate:
-		return filter.setFloatProperty(tag, value, 0, 10000)
+		return setFloatProperty(properties, tag, value, 0, 10000)
 
 	case Grayscale, Invert, Opacity, Sepia:
-		return filter.setFloatProperty(tag, value, 0, 100)
+		return setFloatProperty(properties, tag, value, 0, 100)
 
 	case HueRotate:
-		return filter.setAngleProperty(tag, value)
+		return setAngleProperty(properties, tag, value)
 
 	case DropShadow:
-		return filter.setShadow(tag, value)
+		if setShadowProperty(properties, tag, value) {
+			return []PropertyName{tag}
+		}
 	}
 
 	ErrorLogF(`"%s" property is not supported by the view filter`, tag)
-	return false
+	return nil
 }
 
 func (filter *viewFilter) String() string {
@@ -225,7 +226,7 @@ func (filter *viewFilter) writeString(buffer *strings.Builder, indent string) {
 			if comma {
 				buffer.WriteString(", ")
 			}
-			buffer.WriteString(tag)
+			buffer.WriteString(string(tag))
 			buffer.WriteString(" = ")
 			writePropertyValue(buffer, tag, value, indent)
 			comma = true
@@ -239,18 +240,18 @@ func (filter *viewFilter) cssStyle(session Session) string {
 	defer freeStringBuilder(buffer)
 
 	if value, ok := floatTextProperty(filter, Blur, session, 0); ok {
-		buffer.WriteString(Blur)
+		buffer.WriteString(string(Blur))
 		buffer.WriteRune('(')
 		buffer.WriteString(value)
 		buffer.WriteString("px)")
 	}
 
-	for _, tag := range []string{Brightness, Contrast, Saturate, Grayscale, Invert, Opacity, Sepia} {
+	for _, tag := range []PropertyName{Brightness, Contrast, Saturate, Grayscale, Invert, Opacity, Sepia} {
 		if value, ok := floatTextProperty(filter, tag, session, 0); ok {
 			if buffer.Len() > 0 {
 				buffer.WriteRune(' ')
 			}
-			buffer.WriteString(tag)
+			buffer.WriteString(string(tag))
 			buffer.WriteRune('(')
 			buffer.WriteString(value)
 			buffer.WriteString("%)")
@@ -261,7 +262,7 @@ func (filter *viewFilter) cssStyle(session Session) string {
 		if buffer.Len() > 0 {
 			buffer.WriteRune(' ')
 		}
-		buffer.WriteString(HueRotate)
+		buffer.WriteString(string(HueRotate))
 		buffer.WriteRune('(')
 		buffer.WriteString(value.cssString())
 		buffer.WriteRune(')')
@@ -284,36 +285,37 @@ func (filter *viewFilter) cssStyle(session Session) string {
 	return buffer.String()
 }
 
-func (style *viewStyle) setFilter(tag string, value any) bool {
+func setFilterProperty(properties Properties, tag PropertyName, value any) []PropertyName {
 	switch value := value.(type) {
 	case ViewFilter:
-		style.properties[tag] = value
+		properties.setRaw(tag, value)
-		return true
+		return []PropertyName{tag}
 
 	case string:
 		if obj := NewDataObject(value); obj == nil {
 			if filter := newViewFilter(obj); filter != nil {
-				style.properties[tag] = filter
+				properties.setRaw(tag, filter)
-				return true
+				return []PropertyName{tag}
 			}
 		}
+
 	case DataObject:
 		if filter := newViewFilter(value); filter != nil {
-			style.properties[tag] = filter
+			properties.setRaw(tag, filter)
-			return true
+			return []PropertyName{tag}
 		}
 
 	case DataValue:
 		if value.IsObject() {
 			if filter := newViewFilter(value.Object()); filter != nil {
-				style.properties[tag] = filter
+				properties.setRaw(tag, filter)
-				return true
+				return []PropertyName{tag}
 			}
 		}
 	}
 
 	notCompatibleType(tag, value)
-	return false
+	return nil
 }
 
 // GetFilter returns a View graphical effects like blur or color shift.

viewStyle.go

@@ -12,72 +12,31 @@ type ViewStyle interface {
 	Properties
 
 	// Transition returns the transition animation of the property. Returns nil is there is no transition animation.
-	Transition(tag string) Animation
+	Transition(tag PropertyName) Animation
 
 	// Transitions returns the map of transition animations. The result is always non-nil.
-	Transitions() map[string]Animation
+	Transitions() map[PropertyName]Animation
 
 	// SetTransition sets the transition animation for the property if "animation" argument is not nil, and
 	// removes the transition animation of the property if "animation" argument  is nil.
 	// The "tag" argument is the property name.
-	SetTransition(tag string, animation Animation)
+	SetTransition(tag PropertyName, animation Animation)
 
 	cssViewStyle(buffer cssBuilder, session Session)
 }
 
 type viewStyle struct {
 	propertyList
-	transitions map[string]Animation
+	//transitions map[PropertyName]Animation
-}
-
-// Range defines range limits. The First and Last value are included in the range
-type Range struct {
-	First, Last int
 }
 
 type stringWriter interface {
 	writeString(buffer *strings.Builder, indent string)
 }
 
-// String returns a string representation of the Range struct
-func (r Range) String() string {
-	if r.First == r.Last {
-		return fmt.Sprintf("%d", r.First)
-	}
-	return fmt.Sprintf("%d:%d", r.First, r.Last)
-}
-
-func (r *Range) setValue(value string) bool {
-	var err error
-	if strings.Contains(value, ":") {
-		values := strings.Split(value, ":")
-		if len(values) != 2 {
-			ErrorLog("Invalid range value: " + value)
-			return false
-		}
-		if r.First, err = strconv.Atoi(strings.Trim(values[0], " \t\n\r")); err != nil {
-			ErrorLog(`Invalid first range value "` + value + `" (` + err.Error() + ")")
-			return false
-		}
-		if r.Last, err = strconv.Atoi(strings.Trim(values[1], " \t\n\r")); err != nil {
-			ErrorLog(`Invalid last range value "` + value + `" (` + err.Error() + ")")
-			return false
-		}
-		return true
-	}
-
-	if r.First, err = strconv.Atoi(value); err != nil {
-		ErrorLog(`Invalid range value "` + value + `" (` + err.Error() + ")")
-		return false
-	}
-	r.Last = r.First
-	return true
-}
-
 func (style *viewStyle) init() {
 	style.propertyList.init()
-	//style.shadows = []ViewShadow{}
+	style.normalize = normalizeViewStyleTag
-	style.transitions = map[string]Animation{}
 }
 
 // NewViewStyle create new ViewStyle object
@@ -90,19 +49,19 @@ func NewViewStyle(params Params) ViewStyle {
 	return style
 }
 
-func (style *viewStyle) cssTextDecoration(session Session) string {
+func textDecorationCSS(properties Properties, session Session) string {
 	buffer := allocStringBuilder()
 	defer freeStringBuilder(buffer)
 
 	noDecoration := false
-	if strikethrough, ok := boolProperty(style, Strikethrough, session); ok {
+	if strikethrough, ok := boolProperty(properties, Strikethrough, session); ok {
 		if strikethrough {
 			buffer.WriteString("line-through")
 		}
 		noDecoration = true
 	}
 
-	if overline, ok := boolProperty(style, Overline, session); ok {
+	if overline, ok := boolProperty(properties, Overline, session); ok {
 		if overline {
 			if buffer.Len() > 0 {
 				buffer.WriteRune(' ')
@@ -112,7 +71,7 @@ func (style *viewStyle) cssTextDecoration(session Session) string {
 		noDecoration = true
 	}
 
-	if underline, ok := boolProperty(style, Underline, session); ok {
+	if underline, ok := boolProperty(properties, Underline, session); ok {
 		if underline {
 			if buffer.Len() > 0 {
 				buffer.WriteRune(' ')
@@ -149,8 +108,8 @@ func split4Values(text string) []string {
 	return []string{}
 }
 
-func (style *viewStyle) backgroundCSS(session Session) string {
+func backgroundCSS(properties Properties, session Session) string {
-	if value, ok := style.properties[Background]; ok {
+	if value := properties.getRaw(Background); value != nil {
 		if backgrounds, ok := value.([]BackgroundElement); ok {
 			buffer := allocStringBuilder()
 			defer freeStringBuilder(buffer)
@@ -184,15 +143,15 @@ func (style *viewStyle) cssViewStyle(builder cssBuilder, session Session) {
 		}
 	}
 
-	if margin, ok := boundsProperty(style, Margin, session); ok {
+	if margin, ok := getBounds(style, Margin, session); ok {
 		margin.cssValue(Margin, builder, session)
 	}
 
-	if padding, ok := boundsProperty(style, Padding, session); ok {
+	if padding, ok := getBounds(style, Padding, session); ok {
 		padding.cssValue(Padding, builder, session)
 	}
 
-	if border := getBorder(style, Border); border != nil {
+	if border := getBorderProperty(style, Border); border != nil {
 		border.cssStyle(builder, session)
 		border.cssWidth(builder, session)
 		border.cssColor(builder, session)
@@ -201,27 +160,27 @@ func (style *viewStyle) cssViewStyle(builder cssBuilder, session Session) {
 	radius := getRadius(style, session)
 	radius.cssValue(builder, session)
 
-	if outline := getOutline(style); outline != nil {
+	if outline := getOutlineProperty(style); outline != nil {
 		outline.ViewOutline(session).cssValue(builder, session)
 	}
 
-	for _, tag := range []string{ZIndex, Order} {
+	for _, tag := range []PropertyName{ZIndex, Order} {
 		if value, ok := intProperty(style, tag, session, 0); ok {
-			builder.add(tag, strconv.Itoa(value))
+			builder.add(string(tag), strconv.Itoa(value))
 		}
 	}
 
 	if opacity, ok := floatProperty(style, Opacity, session, 1.0); ok && opacity >= 0 && opacity <= 1 {
-		builder.add(Opacity, strconv.FormatFloat(opacity, 'f', 3, 32))
+		builder.add(string(Opacity), strconv.FormatFloat(opacity, 'f', 3, 32))
 	}
 
-	for _, tag := range []string{ColumnCount, TabSize} {
+	for _, tag := range []PropertyName{ColumnCount, TabSize} {
 		if value, ok := intProperty(style, tag, session, 0); ok && value > 0 {
-			builder.add(tag, strconv.Itoa(value))
+			builder.add(string(tag), strconv.Itoa(value))
 		}
 	}
 
-	for _, tag := range []string{
+	for _, tag := range []PropertyName{
 		Width, Height, MinWidth, MinHeight, MaxWidth, MaxHeight, Left, Right, Top, Bottom,
 		TextSize, TextIndent, LetterSpacing, WordSpacing, LineHeight, TextLineThickness,
 		ListRowGap, ListColumnGap, GridRowGap, GridColumnGap, ColumnGap, ColumnWidth, OutlineOffset} {
@@ -229,18 +188,22 @@ func (style *viewStyle) cssViewStyle(builder cssBuilder, session Session) {
 		if size, ok := sizeProperty(style, tag, session); ok && size.Type != Auto {
 			cssTag, ok := sizeProperties[tag]
 			if !ok {
-				cssTag = tag
+				cssTag = string(tag)
 			}
 			builder.add(cssTag, size.cssString("", session))
 		}
 	}
 
-	colorProperties := []struct{ property, cssTag string }{
+	type propertyCss struct {
-		{BackgroundColor, BackgroundColor},
+		property PropertyName
+		cssTag   string
+	}
+	colorProperties := []propertyCss{
+		{BackgroundColor, string(BackgroundColor)},
 		{TextColor, "color"},
 		{TextLineColor, "text-decoration-color"},
-		{CaretColor, CaretColor},
+		{CaretColor, string(CaretColor)},
-		{AccentColor, AccentColor},
+		{AccentColor, string(AccentColor)},
 	}
 	for _, p := range colorProperties {
 		if color, ok := colorProperty(style, p.property, session); ok && color != 0 {
@@ -249,10 +212,10 @@ func (style *viewStyle) cssViewStyle(builder cssBuilder, session Session) {
 	}
 
 	if value, ok := enumProperty(style, BackgroundClip, session, 0); ok {
-		builder.add(BackgroundClip, enumProperties[BackgroundClip].values[value])
+		builder.add(string(BackgroundClip), enumProperties[BackgroundClip].values[value])
 	}
 
-	if background := style.backgroundCSS(session); background != "" {
+	if background := backgroundCSS(style, session); background != "" {
 		builder.add("background", background)
 	}
 
@@ -261,7 +224,7 @@ func (style *viewStyle) cssViewStyle(builder cssBuilder, session Session) {
 	}
 
 	writingMode := 0
-	for _, tag := range []string{
+	for _, tag := range []PropertyName{
 		Overflow, TextAlign, TextTransform, TextWeight, TextLineStyle, WritingMode, TextDirection,
 		VerticalTextOrientation, CellVerticalAlign, CellHorizontalAlign, GridAutoFlow, Cursor,
 		WhiteSpace, WordBreak, TextOverflow, Float, TableVerticalAlign, Resize, MixBlendMode, BackgroundBlendMode} {
@@ -282,7 +245,11 @@ func (style *viewStyle) cssViewStyle(builder cssBuilder, session Session) {
 		}
 	}
 
-	for _, prop := range []struct{ tag, cssTag, off, on string }{
+	type boolPropertyCss struct {
+		tag             PropertyName
+		cssTag, off, on string
+	}
+	for _, prop := range []boolPropertyCss{
 		{tag: Italic, cssTag: "font-style", off: "normal", on: "italic"},
 		{tag: SmallCaps, cssTag: "font-variant", off: "normal", on: "small-caps"},
 	} {
@@ -295,7 +262,7 @@ func (style *viewStyle) cssViewStyle(builder cssBuilder, session Session) {
 		}
 	}
 
-	if text := style.cssTextDecoration(session); text != "" {
+	if text := textDecorationCSS(style, session); text != "" {
 		builder.add("text-decoration", text)
 	}
 
@@ -416,10 +383,10 @@ func (style *viewStyle) cssViewStyle(builder cssBuilder, session Session) {
 	if r, ok := rangeProperty(style, Column, session); ok {
 		builder.add("grid-column", fmt.Sprintf("%d / %d", r.First+1, r.Last+2))
 	}
-	if text := style.gridCellSizesCSS(CellWidth, session); text != "" {
+	if text := gridCellSizesCSS(style, CellWidth, session); text != "" {
 		builder.add(`grid-template-columns`, text)
 	}
-	if text := style.gridCellSizesCSS(CellHeight, session); text != "" {
+	if text := gridCellSizesCSS(style, CellHeight, session); text != "" {
 		builder.add(`grid-template-rows`, text)
 	}
 
@@ -436,7 +403,7 @@ func (style *viewStyle) cssViewStyle(builder cssBuilder, session Session) {
 	if value := style.getRaw(Filter); value != nil {
 		if filter, ok := value.(ViewFilter); ok {
 			if text := filter.cssStyle(session); text != "" {
-				builder.add(Filter, text)
+				builder.add(string(Filter), text)
 			}
 		}
 	}
@@ -445,17 +412,17 @@ func (style *viewStyle) cssViewStyle(builder cssBuilder, session Session) {
 		if filter, ok := value.(ViewFilter); ok {
 			if text := filter.cssStyle(session); text != "" {
 				builder.add(`-webkit-backdrop-filter`, text)
-				builder.add(BackdropFilter, text)
+				builder.add(string(BackdropFilter), text)
 			}
 		}
 	}
 
-	if transition := style.transitionCSS(session); transition != "" {
+	if transition := transitionCSS(style, session); transition != "" {
 		builder.add(`transition`, transition)
 	}
 
-	if animation := style.animationCSS(session); animation != "" {
+	if animation := animationCSS(style, session); animation != "" {
-		builder.add(AnimationTag, animation)
+		builder.add(string(AnimationTag), animation)
 	}
 
 	if pause, ok := boolProperty(style, AnimationPaused, session); ok {
@@ -504,20 +471,48 @@ func valueToOrientation(value any, session Session) (int, bool) {
 	return 0, false
 }
 
-func (style *viewStyle) Get(tag string) any {
+func normalizeViewStyleTag(tag PropertyName) PropertyName {
-	return style.get(strings.ToLower(tag))
+	tag = defaultNormalize(tag)
+	switch tag {
+	case "top-margin":
+		return MarginTop
+
+	case "right-margin":
+		return MarginRight
+
+	case "bottom-margin":
+		return MarginBottom
+
+	case "left-margin":
+		return MarginLeft
+
+	case "top-padding":
+		return PaddingTop
+
+	case "right-padding":
+		return PaddingRight
+
+	case "bottom-padding":
+		return PaddingBottom
+
+	case "left-padding":
+		return PaddingLeft
+	}
+	return tag
 }
 
-func (style *viewStyle) get(tag string) any {
+func (style *viewStyle) Get(tag PropertyName) any {
+	return viewStyleGet(style, normalizeViewStyleTag(tag))
+}
+
+func viewStyleGet(style Properties, tag PropertyName) any {
 	switch tag {
-	case Border, CellBorder:
-		return getBorder(&style.propertyList, tag)
 
 	case BorderLeft, BorderRight, BorderTop, BorderBottom,
 		BorderStyle, BorderLeftStyle, BorderRightStyle, BorderTopStyle, BorderBottomStyle,
 		BorderColor, BorderLeftColor, BorderRightColor, BorderTopColor, BorderBottomColor,
 		BorderWidth, BorderLeftWidth, BorderRightWidth, BorderTopWidth, BorderBottomWidth:
-		if border := getBorder(style, Border); border != nil {
+		if border := getBorderProperty(style, Border); border != nil {
 			return border.Get(tag)
 		}
 		return nil
@@ -526,7 +521,7 @@ func (style *viewStyle) get(tag string) any {
 		CellBorderStyle, CellBorderLeftStyle, CellBorderRightStyle, CellBorderTopStyle, CellBorderBottomStyle,
 		CellBorderColor, CellBorderLeftColor, CellBorderRightColor, CellBorderTopColor, CellBorderBottomColor,
 		CellBorderWidth, CellBorderLeftWidth, CellBorderRightWidth, CellBorderTopWidth, CellBorderBottomWidth:
-		if border := getBorder(style, CellBorder); border != nil {
+		if border := getBorderProperty(style, CellBorder); border != nil {
 			return border.Get(tag)
 		}
 		return nil
@@ -537,46 +532,22 @@ func (style *viewStyle) get(tag string) any {
 		RadiusBottomRight, RadiusBottomRightX, RadiusBottomRightY:
 		return getRadiusElement(style, tag)
 
-	case ColumnSeparator:
-		if val, ok := style.properties[ColumnSeparator]; ok {
-			return val.(ColumnSeparatorProperty)
-		}
-		return nil
-
 	case ColumnSeparatorStyle, ColumnSeparatorWidth, ColumnSeparatorColor:
-		if val, ok := style.properties[ColumnSeparator]; ok {
+		if val := style.getRaw(ColumnSeparator); val != nil {
 			separator := val.(ColumnSeparatorProperty)
 			return separator.Get(tag)
 		}
 		return nil
 
-	case Transition:
-		if len(style.transitions) == 0 {
-			return nil
-		}
-		result := map[string]Animation{}
-		for tag, animation := range style.transitions {
-			result[tag] = animation
-		}
-		return result
-
 	case RotateX, RotateY, RotateZ, Rotate, SkewX, SkewY, ScaleX, ScaleY, ScaleZ,
 		TranslateX, TranslateY, TranslateZ:
-		if transform := style.transformProperty(); transform != nil {
+		if transform := getTransformProperty(style); transform != nil {
 			return transform.Get(tag)
 		}
 		return nil
 	}
 
-	return style.propertyList.getRaw(tag)
+	return style.getRaw(tag)
-}
-
-func (style *viewStyle) AllTags() []string {
-	result := style.propertyList.AllTags()
-	if len(style.transitions) > 0 {
-		result = append(result, Transition)
-	}
-	return result
 }
 
 func supportedPropertyValue(value any) bool {
@@ -595,14 +566,14 @@ func supportedPropertyValue(value any) bool {
 	case []BackgroundElement:
 	case []BackgroundGradientPoint:
 	case []BackgroundGradientAngle:
-	case map[string]Animation:
+	case map[PropertyName]Animation:
 	default:
 		return false
 	}
 	return true
 }
 
-func writePropertyValue(buffer *strings.Builder, tag string, value any, indent string) {
+func writePropertyValue(buffer *strings.Builder, tag PropertyName, value any, indent string) {
 
 	writeString := func(text string) {
 		simple := (tag != Text && tag != Title && tag != Summary)
@@ -804,7 +775,7 @@ func writePropertyValue(buffer *strings.Builder, tag string, value any, indent s
 		}
 		buffer.WriteRune('"')
 
-	case map[string]Animation:
+	case map[PropertyName]Animation:
 		switch count := len(value); count {
 		case 0:
 			buffer.WriteString("[]")
@@ -816,11 +787,13 @@ func writePropertyValue(buffer *strings.Builder, tag string, value any, indent s
 			}
 
 		default:
-			tags := make([]string, 0, len(value))
+			tags := make([]PropertyName, 0, len(value))
 			for tag := range value {
 				tags = append(tags, tag)
 			}
-			sort.Strings(tags)
+			sort.Slice(tags, func(i, j int) bool {
+				return tags[i] < tags[j]
+			})
 			buffer.WriteString("[\n")
 			indent2 := indent + "\t"
 			for _, tag := range tags {
@@ -836,12 +809,12 @@ func writePropertyValue(buffer *strings.Builder, tag string, value any, indent s
 	}
 }
 
-func writeViewStyle(name string, view ViewStyle, buffer *strings.Builder, indent string, excludeTags []string) {
+func writeViewStyle(name string, view Properties, buffer *strings.Builder, indent string, excludeTags []PropertyName) {
 	buffer.WriteString(name)
 	buffer.WriteString(" {\n")
 	indent += "\t"
 
-	writeProperty := func(tag string, value any) {
+	writeProperty := func(tag PropertyName, value any) {
 		for _, exclude := range excludeTags {
 			if exclude == tag {
 				return
@@ -850,7 +823,7 @@ func writeViewStyle(name string, view ViewStyle, buffer *strings.Builder, indent
 
 		if supportedPropertyValue(value) {
 			buffer.WriteString(indent)
-			buffer.WriteString(tag)
+			buffer.WriteString(string(tag))
 			buffer.WriteString(" = ")
 			writePropertyValue(buffer, tag, value, indent)
 			buffer.WriteString(",\n")
@@ -858,7 +831,7 @@ func writeViewStyle(name string, view ViewStyle, buffer *strings.Builder, indent
 	}
 
 	tags := view.AllTags()
-	removeTag := func(tag string) {
+	removeTag := func(tag PropertyName) {
 		for i, t := range tags {
 			if t == tag {
 				if i == 0 {
@@ -873,7 +846,7 @@ func writeViewStyle(name string, view ViewStyle, buffer *strings.Builder, indent
 		}
 	}
 
-	tagOrder := []string{
+	tagOrder := []PropertyName{
 		ID, Row, Column, Top, Right, Bottom, Left, Semantics, Cursor, Visibility,
 		Opacity, ZIndex, Width, Height, MinWidth, MinHeight, MaxWidth, MaxHeight,
 		Margin, Padding, BackgroundClip, BackgroundColor, Background, Border, Radius, Outline, Shadow,
@@ -894,7 +867,7 @@ func writeViewStyle(name string, view ViewStyle, buffer *strings.Builder, indent
 		}
 	}
 
-	finalTags := []string{
+	finalTags := []PropertyName{
 		Perspective, PerspectiveOriginX, PerspectiveOriginY, BackfaceVisible, OriginX, OriginY, OriginZ,
 		TransformTag, Clip, Filter, BackdropFilter, Summary, Content, Transition}
 	for _, tag := range finalTags {
@@ -918,14 +891,6 @@ func writeViewStyle(name string, view ViewStyle, buffer *strings.Builder, indent
 	buffer.WriteString("}")
 }
 
-func getViewString(view View, excludeTags []string) string {
-	buffer := allocStringBuilder()
-	defer freeStringBuilder(buffer)
-	writeViewStyle(view.Tag(), view, buffer, "", excludeTags)
-	return buffer.String()
-
-}
-
 func runStringWriter(writer stringWriter) string {
 	buffer := allocStringBuilder()
 	defer freeStringBuilder(buffer)

viewStyleSet.go

@@ -4,87 +4,94 @@ import (
 	"strings"
 )
 
-func (style *viewStyle) setRange(tag string, value any) bool {
+func setTransitionProperty(properties Properties, value any) bool {
-	switch value := value.(type) {
-	case string:
-		if strings.Contains(value, "@") {
-			style.properties[tag] = value
-			return true
-		}
-		var r Range
-		if !r.setValue(value) {
-			invalidPropertyValue(tag, value)
-			return false
-		}
-		style.properties[tag] = r
 
-	case int:
+	transitions := map[PropertyName]Animation{}
-		style.properties[tag] = Range{First: value, Last: value}
 
-	case Range:
-		style.properties[tag] = value
-
-	default:
-		notCompatibleType(tag, value)
-		return false
-	}
-	return true
-}
-
-func (style *viewStyle) setBackground(value any) bool {
-	background := []BackgroundElement{}
-
-	switch value := value.(type) {
-	case BackgroundElement:
-		background = []BackgroundElement{value}
-
-	case []BackgroundElement:
-		background = value
-
-	case []DataValue:
-		for _, el := range value {
-			if el.IsObject() {
-				if element := createBackground(el.Object()); element != nil {
-					background = append(background, element)
-				}
-			} else if obj := ParseDataText(el.Value()); obj != nil {
-				if element := createBackground(obj); element != nil {
-					background = append(background, element)
-				}
-			}
-		}
-
-	case DataObject:
-		if element := createBackground(value); element != nil {
-			background = []BackgroundElement{element}
-		}
-
-	case []DataObject:
-		for _, obj := range value {
-			if element := createBackground(obj); element != nil {
-				background = append(background, element)
-			}
-		}
-
-	case string:
-		if obj := ParseDataText(value); obj != nil {
-			if element := createBackground(obj); element != nil {
-				background = []BackgroundElement{element}
-			}
-		}
-	}
-
-	if len(background) > 0 {
-		style.properties[Background] = background
-		return true
-	}
-	return false
-}
-
-func (style *viewStyle) setTransition(tag string, value any) bool {
 	setObject := func(obj DataObject) bool {
 		if obj != nil {
-			tag := strings.ToLower(tag)
+			tag := strings.ToLower(obj.Tag())
+			switch tag {
+			case "", "_":
+				ErrorLog("Invalid transition property name")
+
+			default:
+				transitions[PropertyName(tag)] = parseAnimation(obj)
+				return true
+			}
+		}
+		return false
+	}
+
+	switch value := value.(type) {
+	case Params:
+		for tag, val := range value {
+			tag = defaultNormalize(tag)
+			if tag == "" {
+				ErrorLog("Invalid transition property name")
+				return false
+			}
+
+			if val != nil {
+				if animation, ok := val.(Animation); ok {
+					transitions[PropertyName(tag)] = animation
+				} else {
+					notCompatibleType(Transition, val)
+					return false
+				}
+			}
+		}
+		if len(transitions) == 0 {
+			transitions = nil
+		}
+		properties.setRaw(Transition, transitions)
+		return true
+
+	case DataObject:
+		if setObject(value) {
+			properties.setRaw(Transition, transitions)
+			return true
+		}
+		return false
+
+	case DataNode:
+		switch value.Type() {
+		case ObjectNode:
+			if setObject(value.Object()) {
+				properties.setRaw(Transition, transitions)
+				return true
+			}
+			return false
+
+		case ArrayNode:
+			for i := 0; i < value.ArraySize(); i++ {
+				if obj := value.ArrayElement(i).Object(); obj != nil {
+					if !setObject(obj) {
+						return false
+					}
+				} else {
+					notCompatibleType(Transition, value.ArrayElement(i))
+					return false
+				}
+			}
+			if len(transitions) == 0 {
+				transitions = nil
+			}
+			properties.setRaw(Transition, transitions)
+			return true
+		}
+	}
+
+	notCompatibleType(Transition, value)
+	return false
+
+}
+
+/*
+	func (style *viewStyle) setTransition(tag PropertyName, value any) bool {
+		setObject := func(obj DataObject) bool {
+			if obj != nil {
+				tag := defaultNormalize(tag)
 				switch tag {
 				case "", "_":
 					ErrorLog("Invalid transition property name")
@@ -101,7 +108,7 @@ func (style *viewStyle) setTransition(tag string, value any) bool {
 		case Params:
 			result := true
 			for tag, val := range value {
-			tag = strings.ToLower(strings.Trim(tag, " \t"))
+				tag = defaultNormalize(tag)
 				if tag == "" {
 					ErrorLog("Invalid transition property name")
 					result = false
@@ -141,69 +148,17 @@ func (style *viewStyle) setTransition(tag string, value any) bool {
 		notCompatibleType(tag, value)
 		return false
 	}
+*/
 
-func (style *viewStyle) setAnimation(tag string, value any) bool {
+func viewStyleRemove(properties Properties, tag PropertyName) []PropertyName {
-
-	set := func(animations []Animation) {
-		style.properties[tag] = animations
-		for _, animation := range animations {
-			animation.used()
-		}
-	}
-
-	switch value := value.(type) {
-	case Animation:
-		set([]Animation{value})
-		return true
-
-	case []Animation:
-		set(value)
-		return true
-
-	case DataObject:
-		if animation := parseAnimation(value); animation.hasAnimatedProperty() {
-			set([]Animation{animation})
-			return true
-		}
-
-	case DataNode:
-		animations := []Animation{}
-		result := true
-		for i := 0; i < value.ArraySize(); i++ {
-			if obj := value.ArrayElement(i).Object(); obj != nil {
-				if anim := parseAnimation(obj); anim.hasAnimatedProperty() {
-					animations = append(animations, anim)
-				} else {
-					result = false
-				}
-			} else {
-				notCompatibleType(tag, value.ArrayElement(i))
-				result = false
-			}
-		}
-		if result && len(animations) > 0 {
-			set(animations)
-		}
-		return result
-	}
-
-	notCompatibleType(tag, value)
-	return false
-}
-
-func (style *viewStyle) Remove(tag string) {
-	style.remove(strings.ToLower(tag))
-}
-
-func (style *viewStyle) remove(tag string) {
 	switch tag {
 	case BorderStyle, BorderColor, BorderWidth,
 		BorderLeft, BorderLeftStyle, BorderLeftColor, BorderLeftWidth,
 		BorderRight, BorderRightStyle, BorderRightColor, BorderRightWidth,
 		BorderTop, BorderTopStyle, BorderTopColor, BorderTopWidth,
 		BorderBottom, BorderBottomStyle, BorderBottomColor, BorderBottomWidth:
-		if border := getBorder(style, Border); border != nil {
+		if border := getBorderProperty(properties, Border); border != nil && border.deleteTag(tag) {
-			border.delete(tag)
+			return []PropertyName{Border}
 		}
 
 	case CellBorderStyle, CellBorderColor, CellBorderWidth,
@@ -211,58 +166,59 @@ func (style *viewStyle) remove(tag string) {
 		CellBorderRight, CellBorderRightStyle, CellBorderRightColor, CellBorderRightWidth,
 		CellBorderTop, CellBorderTopStyle, CellBorderTopColor, CellBorderTopWidth,
 		CellBorderBottom, CellBorderBottomStyle, CellBorderBottomColor, CellBorderBottomWidth:
-		if border := getBorder(style, CellBorder); border != nil {
+		if border := getBorderProperty(properties, CellBorder); border != nil && border.deleteTag(tag) {
-			border.delete(tag)
+			return []PropertyName{CellBorder}
 		}
 
-	case MarginTop, MarginRight, MarginBottom, MarginLeft,
+	case MarginTop, MarginRight, MarginBottom, MarginLeft:
-		"top-margin", "right-margin", "bottom-margin", "left-margin":
+		return removeBoundsPropertySide(properties, Margin, tag)
-		style.removeBoundsSide(Margin, tag)
 
-	case PaddingTop, PaddingRight, PaddingBottom, PaddingLeft,
+	case PaddingTop, PaddingRight, PaddingBottom, PaddingLeft:
-		"top-padding", "right-padding", "bottom-padding", "left-padding":
+		return removeBoundsPropertySide(properties, Padding, tag)
-		style.removeBoundsSide(Padding, tag)
 
 	case CellPaddingTop, CellPaddingRight, CellPaddingBottom, CellPaddingLeft:
-		style.removeBoundsSide(CellPadding, tag)
+		return removeBoundsPropertySide(properties, CellPadding, tag)
 
 	case RadiusX, RadiusY, RadiusTopLeft, RadiusTopLeftX, RadiusTopLeftY,
 		RadiusTopRight, RadiusTopRightX, RadiusTopRightY,
 		RadiusBottomLeft, RadiusBottomLeftX, RadiusBottomLeftY,
 		RadiusBottomRight, RadiusBottomRightX, RadiusBottomRightY:
-		style.removeRadiusElement(tag)
+		if removeRadiusPropertyElement(properties, tag) {
+			return []PropertyName{Radius, tag}
+		}
 
 	case OutlineStyle, OutlineWidth, OutlineColor:
-		if outline := getOutline(style); outline != nil {
+		if outline := getOutlineProperty(properties); outline != nil {
 			outline.Remove(tag)
+			if outline.empty() {
+				properties.setRaw(Outline, nil)
+			}
+			return []PropertyName{Outline, tag}
 		}
 
 	default:
-		style.propertyList.remove(tag)
+		return propertiesRemove(properties, tag)
-	}
 	}
 
-func (style *viewStyle) Set(tag string, value any) bool {
+	return []PropertyName{}
-	return style.set(strings.ToLower(tag), value)
-}
-
-func (style *viewStyle) set(tag string, value any) bool {
-	if value == nil {
-		style.remove(tag)
-		return true
 }
 
+func viewStyleSet(style Properties, tag PropertyName, value any) []PropertyName {
 	switch tag {
 	case Shadow, TextShadow:
-		return style.setShadow(tag, value)
+		if setShadowProperty(style, tag, value) {
+			return []PropertyName{tag}
+		}
 
 	case Background:
-		return style.setBackground(value)
+		return setBackgroundProperty(style, value)
 
 	case Border, CellBorder:
 		if border := newBorderProperty(value); border != nil {
-			style.properties[tag] = border
+			style.setRaw(tag, border)
-			return true
+			return []PropertyName{tag}
+		} else {
+			return nil
 		}
 
 	case BorderStyle, BorderColor, BorderWidth,
@@ -271,16 +227,7 @@ func (style *viewStyle) set(tag string, value any) bool {
 		BorderTop, BorderTopStyle, BorderTopColor, BorderTopWidth,
 		BorderBottom, BorderBottomStyle, BorderBottomColor, BorderBottomWidth:
 
-		border := getBorder(style, Border)
+		return setBorderPropertyElement(style, Border, tag, value)
-		if border == nil {
-			border = NewBorder(nil)
-			if border.Set(tag, value) {
-				style.properties[Border] = border
-				return true
-			}
-			return false
-		}
-		return border.Set(tag, value)
 
 	case CellBorderStyle, CellBorderColor, CellBorderWidth,
 		CellBorderLeft, CellBorderLeftStyle, CellBorderLeftColor, CellBorderLeftWidth,
@@ -288,173 +235,211 @@ func (style *viewStyle) set(tag string, value any) bool {
 		CellBorderTop, CellBorderTopStyle, CellBorderTopColor, CellBorderTopWidth,
 		CellBorderBottom, CellBorderBottomStyle, CellBorderBottomColor, CellBorderBottomWidth:
 
-		border := getBorder(style, CellBorder)
+		return setBorderPropertyElement(style, CellBorder, tag, value)
-		if border == nil {
-			border = NewBorder(nil)
-			if border.Set(tag, value) {
-				style.properties[CellBorder] = border
-				return true
-			}
-			return false
-		}
-		return border.Set(tag, value)
 
 	case Radius:
-		return style.setRadius(value)
+		return setRadiusProperty(style, value)
 
 	case RadiusX, RadiusY, RadiusTopLeft, RadiusTopLeftX, RadiusTopLeftY,
 		RadiusTopRight, RadiusTopRightX, RadiusTopRightY,
 		RadiusBottomLeft, RadiusBottomLeftX, RadiusBottomLeftY,
 		RadiusBottomRight, RadiusBottomRightX, RadiusBottomRightY:
-		return style.setRadiusElement(tag, value)
+		if setRadiusPropertyElement(style, tag, value) {
+			return []PropertyName{Radius, tag}
+		}
 
 	case Margin, Padding, CellPadding:
-		return style.setBounds(tag, value)
+		return setBoundsProperty(style, tag, value)
 
-	case MarginTop, MarginRight, MarginBottom, MarginLeft,
+	case MarginTop, MarginRight, MarginBottom, MarginLeft:
-		"top-margin", "right-margin", "bottom-margin", "left-margin":
+		return setBoundsPropertySide(style, Margin, tag, value)
-		return style.setBoundsSide(Margin, tag, value)
 
-	case PaddingTop, PaddingRight, PaddingBottom, PaddingLeft,
+	case PaddingTop, PaddingRight, PaddingBottom, PaddingLeft:
-		"top-padding", "right-padding", "bottom-padding", "left-padding":
+		return setBoundsPropertySide(style, Padding, tag, value)
-		return style.setBoundsSide(Padding, tag, value)
 
 	case CellPaddingTop, CellPaddingRight, CellPaddingBottom, CellPaddingLeft:
-		return style.setBoundsSide(CellPadding, tag, value)
+		return setBoundsPropertySide(style, CellPadding, tag, value)
 
 	case HeadStyle, FootStyle:
 		switch value := value.(type) {
 		case string:
-			style.properties[tag] = value
+			style.setRaw(tag, value)
-			return true
 
 		case Params:
-			style.properties[tag] = value
+			style.setRaw(tag, value)
-			return true
 
 		case DataObject:
 			if params := value.ToParams(); len(params) > 0 {
-				style.properties[tag] = params
+				style.setRaw(tag, params)
+			} else {
+				style.setRaw(tag, nil)
 			}
-			return true
+
+		default:
+			notCompatibleType(tag, value)
+			return nil
 		}
+		return []PropertyName{tag}
 
 	case CellStyle, ColumnStyle, RowStyle:
 		switch value := value.(type) {
 		case string:
-			style.properties[tag] = value
+			style.setRaw(tag, value)
-			return true
 
 		case Params:
-			style.properties[tag] = value
+			style.setRaw(tag, value)
-			return true
 
 		case DataObject:
 			if params := value.ToParams(); len(params) > 0 {
-				style.properties[tag] = params
+				style.setRaw(tag, params)
+			} else {
+				style.setRaw(tag, nil)
 			}
-			return true
 
 		case DataNode:
 			switch value.Type() {
 			case TextNode:
 				if text := value.Text(); text != "" {
-					style.properties[tag] = text
+					style.setRaw(tag, text)
+				} else {
+					style.setRaw(tag, nil)
 				}
-				return true
 
 			case ObjectNode:
 				if obj := value.Object(); obj != nil {
 					if params := obj.ToParams(); len(params) > 0 {
-						style.properties[tag] = params
+						style.setRaw(tag, params)
+					} else {
+						style.setRaw(tag, nil)
 					}
-					return true
+				} else {
+					notCompatibleType(tag, value)
+					return nil
 				}
 
-			case ArrayNode:
+			default:
-				// TODO
+				notCompatibleType(tag, value)
+				return nil
 			}
+
+		default:
+			notCompatibleType(tag, value)
+			return nil
 		}
+		return []PropertyName{tag}
 
 	case Outline:
-		return style.setOutline(value)
+		return setOutlineProperty(style, value)
 
 	case OutlineStyle, OutlineWidth, OutlineColor:
-		if outline := getOutline(style); outline != nil {
+		if outline := getOutlineProperty(style); outline != nil {
-			return outline.Set(tag, value)
+			if outline.Set(tag, value) {
+				return []PropertyName{Outline, tag}
 			}
-		style.properties[Outline] = NewOutlineProperty(Params{tag: value})
+		} else {
-		return true
+			outline := NewOutlineProperty(nil)
+			if outline.Set(tag, value) {
+				style.setRaw(Outline, outline)
+				return []PropertyName{Outline, tag}
+			}
+		}
+		return nil
 
 	case TransformTag:
-		return style.setTransform(value)
+		if setTransformProperty(style, value) {
+			return []PropertyName{TransformTag}
+		} else {
+			return nil
+		}
 
-	case RotateX, RotateY, RotateZ, Rotate, SkewX, SkewY, ScaleX, ScaleY, ScaleZ,
+	case Perspective, RotateX, RotateY, RotateZ, Rotate, SkewX, SkewY, ScaleX, ScaleY, ScaleZ,
 		TranslateX, TranslateY, TranslateZ:
-		return style.setTransformProperty(tag, value)
+		return setTransformPropertyElement(style, tag, value)
 
 	case Orientation:
 		if text, ok := value.(string); ok {
 			switch strings.ToLower(text) {
 			case "vertical":
-				style.properties[Orientation] = TopDownOrientation
+				style.setRaw(Orientation, TopDownOrientation)
-				return true
+				return []PropertyName{Orientation}
 
 			case "horizontal":
-				style.properties[Orientation] = StartToEndOrientation
+				style.setRaw(Orientation, StartToEndOrientation)
-				return true
+				return []PropertyName{Orientation}
 			}
 		}
 
 	case TextWeight:
-		if n, ok := value.(int); ok && n >= 100 && n%100 == 0 {
+		if n, ok := value.(int); ok {
+			if n >= 100 && n%100 == 0 {
 				n /= 100
 				if n > 0 && n <= 9 {
-				style.properties[TextWeight] = n
+					style.setRaw(TextWeight, n)
-				return true
+					return []PropertyName{TextWeight}
+				}
 			}
 		}
 
 	case Row, Column:
-		return style.setRange(tag, value)
+		return setRangeProperty(style, tag, value)
 
 	case CellWidth, CellHeight:
-		return style.setGridCellSize(tag, value)
+		return setGridCellSize(style, tag, value)
 
 	case ColumnSeparator:
 		if separator := newColumnSeparatorProperty(value); separator != nil {
-			style.properties[ColumnSeparator] = separator
+			style.setRaw(ColumnSeparator, separator)
-			return true
+			return []PropertyName{tag}
 		}
-		return false
+		return nil
 
 	case ColumnSeparatorStyle, ColumnSeparatorWidth, ColumnSeparatorColor:
-		var separator ColumnSeparatorProperty = nil
+		if separator := getColumnSeparatorProperty(style); separator != nil {
-		if val, ok := style.properties[ColumnSeparator]; ok {
-			separator = val.(ColumnSeparatorProperty)
-		}
-		if separator == nil {
-			separator = newColumnSeparatorProperty(nil)
-		}
-
 			if separator.Set(tag, value) {
-			style.properties[ColumnSeparator] = separator
+				return []PropertyName{ColumnSeparator, tag}
-			return true
 			}
-		return false
+		} else {
+			separator := newColumnSeparatorProperty(nil)
+			if separator.Set(tag, value) {
+				style.setRaw(ColumnSeparator, separator)
+				return []PropertyName{ColumnSeparator, tag}
+			}
+		}
+		return nil
 
 	case Clip, ShapeOutside:
-		return style.setClipShape(tag, value)
+		return setClipShapeProperty(style, tag, value)
 
 	case Filter, BackdropFilter:
-		return style.setFilter(tag, value)
+		return setFilterProperty(style, tag, value)
 
 	case Transition:
-		return style.setTransition(tag, value)
+		if setTransitionProperty(style, value) {
+			return []PropertyName{tag}
+		} else {
+			return nil
+		}
 
 	case AnimationTag:
-		return style.setAnimation(tag, value)
+		if setAnimationProperty(style, tag, value) {
+			return []PropertyName{tag}
+		} else {
+			return nil
+		}
 	}
 
-	return style.propertyList.set(tag, value)
+	return propertiesSet(style, tag, value)
+}
+
+func (style *viewStyle) Set(tag PropertyName, value any) bool {
+	if value == nil {
+		style.Remove(tag)
+		return true
+	}
+
+	return viewStyleSet(style, normalizeViewStyleTag(tag), value) != nil
+}
+
+func (style *viewStyle) Remove(tag PropertyName) {
+	viewStyleRemove(style, normalizeViewStyleTag(tag))
 }

viewTransform.go

@@ -8,87 +8,6 @@ import (
 
 // Constants for [Transform] specific properties
 const (
-	// Perspective is the constant for "perspective" property tag.
-	//
-	// Used by `View`.
-	// Distance between the z-plane and the user in order to give a 3D-positioned element some perspective. Each 3D element 
-	// with z > 0 becomes larger, each 3D-element with z < 0 becomes smaller. The default value is 0 (no 3D effects).
-	//
-	// Supported types: `SizeUnit`, `SizeFunc`, `string`, `float`, `int`.
-	//
-	// Internal type is `SizeUnit`, other types converted to it during assignment.
-	// See `SizeUnit` description for more details.
-	Perspective = "perspective"
-
-	// PerspectiveOriginX is the constant for "perspective-origin-x" property tag.
-	//
-	// Used by `View`.
-	// x-coordinate of the position at which the viewer is looking. It is used as the vanishing point by the "perspective" 
-	// property. The default value is 50%.
-	//
-	// Supported types: `SizeUnit`, `SizeFunc`, `string`, `float`, `int`.
-	//
-	// Internal type is `SizeUnit`, other types converted to it during assignment.
-	// See `SizeUnit` description for more details.
-	PerspectiveOriginX = "perspective-origin-x"
-
-	// PerspectiveOriginY is the constant for "perspective-origin-y" property tag.
-	//
-	// Used by `View`.
-	// y-coordinate of the position at which the viewer is looking. It is used as the vanishing point by the "perspective" 
-	// property. The default value is 50%.
-	//
-	// Supported types: `SizeUnit`, `SizeFunc`, `string`, `float`, `int`.
-	//
-	// Internal type is `SizeUnit`, other types converted to it during assignment.
-	// See `SizeUnit` description for more details.
-	PerspectiveOriginY = "perspective-origin-y"
-
-	// BackfaceVisible is the constant for "backface-visibility" property tag.
-	//
-	// Used by `View`.
-	// Controls whether the back face of a view is visible when turned towards the user. Default value is `true`.
-	//
-	// Supported types: `bool`, `int`, `string`.
-	//
-	// Values:
-	// `true` or `1` or "true", "yes", "on", "1" - Back face is visible when turned towards the user.
-	// `false` or `0` or "false", "no", "off", "0" - Back face is hidden, effectively making the view invisible when turned away from the user.
-	BackfaceVisible = "backface-visibility"
-
-	// OriginX is the constant for "origin-x" property tag.
-	//
-	// Used by `View`.
-	// x-coordinate of the point around which a view transformation is applied. The default value is 50%.
-	//
-	// Supported types: `SizeUnit`, `SizeFunc`, `string`, `float`, `int`.
-	//
-	// Internal type is `SizeUnit`, other types converted to it during assignment.
-	// See `SizeUnit` description for more details.
-	OriginX = "origin-x"
-
-	// OriginY is the constant for "origin-y" property tag.
-	//
-	// Used by `View`.
-	// y-coordinate of the point around which a view transformation is applied. The default value is 50%.
-	//
-	// Supported types: `SizeUnit`, `SizeFunc`, `string`, `float`, `int`.
-	//
-	// Internal type is `SizeUnit`, other types converted to it during assignment.
-	// See `SizeUnit` description for more details.
-	OriginY = "origin-y"
-
-	// OriginZ is the constant for "origin-z" property tag.
-	//
-	// Used by `View`.
-	// z-coordinate of the point around which a view transformation is applied. The default value is 50%.
-	//
-	// Supported types: `SizeUnit`, `SizeFunc`, `string`, `float`, `int`.
-	//
-	// Internal type is `SizeUnit`, other types converted to it during assignment.
-	// See `SizeUnit` description for more details.
-	OriginZ = "origin-z"
-
 	// TransformTag is the constant for "transform" property tag.
 	//
 	// Used by `View`.
@@ -101,7 +20,88 @@ const (
 	// Conversion rules:
 	// `Transform` - stored as is, no conversion performed.
 	// `string` - string representation of `Transform` interface. Example: "_{translate-x = 10px, scale-y = 1.1}".
-	TransformTag = "transform"
+	TransformTag PropertyName = "transform"
+
+	// Perspective is the constant for "perspective" property tag.
+	//
+	// Used by `View`.
+	// Distance between the z-plane and the user in order to give a 3D-positioned element some perspective. Each 3D element
+	// with z > 0 becomes larger, each 3D-element with z < 0 becomes smaller. The default value is 0 (no 3D effects).
+	//
+	// Supported types: `SizeUnit`, `SizeFunc`, `string`, `float`, `int`.
+	//
+	// Internal type is `SizeUnit`, other types converted to it during assignment.
+	// See `SizeUnit` description for more details.
+	Perspective PropertyName = "perspective"
+
+	// PerspectiveOriginX is the constant for "perspective-origin-x" property tag.
+	//
+	// Used by `View`.
+	// x-coordinate of the position at which the viewer is looking. It is used as the vanishing point by the "perspective"
+	// property. The default value is 50%.
+	//
+	// Supported types: `SizeUnit`, `SizeFunc`, `string`, `float`, `int`.
+	//
+	// Internal type is `SizeUnit`, other types converted to it during assignment.
+	// See `SizeUnit` description for more details.
+	PerspectiveOriginX PropertyName = "perspective-origin-x"
+
+	// PerspectiveOriginY is the constant for "perspective-origin-y" property tag.
+	//
+	// Used by `View`.
+	// y-coordinate of the position at which the viewer is looking. It is used as the vanishing point by the "perspective"
+	// property. The default value is 50%.
+	//
+	// Supported types: `SizeUnit`, `SizeFunc`, `string`, `float`, `int`.
+	//
+	// Internal type is `SizeUnit`, other types converted to it during assignment.
+	// See `SizeUnit` description for more details.
+	PerspectiveOriginY PropertyName = "perspective-origin-y"
+
+	// BackfaceVisible is the constant for "backface-visibility" property tag.
+	//
+	// Used by `View`.
+	// Controls whether the back face of a view is visible when turned towards the user. Default value is `true`.
+	//
+	// Supported types: `bool`, `int`, `string`.
+	//
+	// Values:
+	// `true` or `1` or "true", "yes", "on", "1" - Back face is visible when turned towards the user.
+	// `false` or `0` or "false", "no", "off", "0" - Back face is hidden, effectively making the view invisible when turned away from the user.
+	BackfaceVisible PropertyName = "backface-visibility"
+
+	// OriginX is the constant for "origin-x" property tag.
+	//
+	// Used by `View`.
+	// x-coordinate of the point around which a view transformation is applied. The default value is 50%.
+	//
+	// Supported types: `SizeUnit`, `SizeFunc`, `string`, `float`, `int`.
+	//
+	// Internal type is `SizeUnit`, other types converted to it during assignment.
+	// See `SizeUnit` description for more details.
+	OriginX PropertyName = "origin-x"
+
+	// OriginY is the constant for "origin-y" property tag.
+	//
+	// Used by `View`.
+	// y-coordinate of the point around which a view transformation is applied. The default value is 50%.
+	//
+	// Supported types: `SizeUnit`, `SizeFunc`, `string`, `float`, `int`.
+	//
+	// Internal type is `SizeUnit`, other types converted to it during assignment.
+	// See `SizeUnit` description for more details.
+	OriginY PropertyName = "origin-y"
+
+	// OriginZ is the constant for "origin-z" property tag.
+	//
+	// Used by `View`.
+	// z-coordinate of the point around which a view transformation is applied. The default value is 50%.
+	//
+	// Supported types: `SizeUnit`, `SizeFunc`, `string`, `float`, `int`.
+	//
+	// Internal type is `SizeUnit`, other types converted to it during assignment.
+	// See `SizeUnit` description for more details.
+	OriginZ PropertyName = "origin-z"
 
 	// TranslateX is the constant for "translate-x" property tag.
 	//
@@ -122,7 +122,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	TranslateX = "translate-x"
+	TranslateX PropertyName = "translate-x"
 
 	// TranslateY is the constant for "translate-y" property tag.
 	//
@@ -143,7 +143,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	TranslateY = "translate-y"
+	TranslateY PropertyName = "translate-y"
 
 	// TranslateZ is the constant for "translate-z" property tag.
 	//
@@ -164,7 +164,7 @@ const (
 	//
 	// Internal type is `SizeUnit`, other types converted to it during assignment.
 	// See `SizeUnit` description for more details.
-	TranslateZ = "translate-z"
+	TranslateZ PropertyName = "translate-z"
 
 	// ScaleX is the constant for "scale-x" property tag.
 	//
@@ -185,7 +185,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	ScaleX = "scale-x"
+	ScaleX PropertyName = "scale-x"
 
 	// ScaleY is the constant for "scale-y" property tag.
 	//
@@ -206,7 +206,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	ScaleY = "scale-y"
+	ScaleY PropertyName = "scale-y"
 
 	// ScaleZ is the constant for "scale-z" property tag.
 	//
@@ -227,7 +227,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	ScaleZ = "scale-z"
+	ScaleZ PropertyName = "scale-z"
 
 	// Rotate is the constant for "rotate" property tag.
 	//
@@ -260,7 +260,7 @@ const (
 	// `string` - must contain string representation of `AngleUnit`. If numeric value will be provided without any suffix then `AngleUnit` with value and `Radian` value type will be created.
 	// `float` - a new `AngleUnit` value will be created with `Radian` as a type.
 	// `int` - a new `AngleUnit` value will be created with `Radian` as a type.
-	Rotate = "rotate"
+	Rotate PropertyName = "rotate"
 
 	// RotateX is the constant for "rotate-x" property tag.
 	//
@@ -279,7 +279,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	RotateX = "rotate-x"
+	RotateX PropertyName = "rotate-x"
 
 	// RotateY is the constant for "rotate-y" property tag.
 	//
@@ -298,7 +298,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	RotateY = "rotate-y"
+	RotateY PropertyName = "rotate-y"
 
 	// RotateZ is the constant for "rotate-z" property tag.
 	//
@@ -317,7 +317,7 @@ const (
 	// Supported types: `float`, `int`, `string`.
 	//
 	// Internal type is `float`, other types converted to it during assignment.
-	RotateZ = "rotate-z"
+	RotateZ PropertyName = "rotate-z"
 
 	// SkewX is the constant for "skew-x" property tag.
 	//
@@ -350,7 +350,7 @@ const (
 	// `string` - must contain string representation of `AngleUnit`. If numeric value will be provided without any suffix then `AngleUnit` with value and `Radian` value type will be created.
 	// `float` - a new `AngleUnit` value will be created with `Radian` as a type.
 	// `int` - a new `AngleUnit` value will be created with `Radian` as a type.
-	SkewX = "skew-x"
+	SkewX PropertyName = "skew-x"
 
 	// SkewY is the constant for "skew-y" property tag.
 	//
@@ -383,44 +383,97 @@ const (
 	// `string` - must contain string representation of `AngleUnit`. If numeric value will be provided without any suffix then `AngleUnit` with value and `Radian` value type will be created.
 	// `float` - a new `AngleUnit` value will be created with `Radian` as a type.
 	// `int` - a new `AngleUnit` value will be created with `Radian` as a type.
-	SkewY = "skew-y"
+	SkewY PropertyName = "skew-y"
 )
 
 // Transform interface specifies view transformation parameters: the x-, y-, and z-axis translation values,
 // the x-, y-, and z-axis scaling values, the angle to use to distort the element along the abscissa and ordinate,
 // the angle of the view rotation.
-// Valid property tags: TranslateX ("translate-x"), TranslateY ("translate-y"), TranslateZ ("translate-z"),
+// Valid property tags: Perspective ("perspective"),  TranslateX ("translate-x"), TranslateY ("translate-y"), TranslateZ ("translate-z"),
 // ScaleX ("scale-x"), ScaleY ("scale-y"), ScaleZ ("scale-z"), Rotate ("rotate"), RotateX ("rotate-x"),
 // RotateY ("rotate-y"), RotateZ ("rotate-z"), SkewX ("skew-x"), and SkewY ("skew-y")
 type Transform interface {
 	Properties
 	fmt.Stringer
 	stringWriter
-	transformCSS(session Session, transform3D bool) string
+	transformCSS(session Session) string
 }
 
 type transformData struct {
-	propertyList
+	dataProperty
 }
 
 // NewTransform creates a new transform property data and return its interface
 func NewTransform(params Params) Transform {
 	transform := new(transformData)
-	transform.properties = map[string]any{}
+	transform.init()
+
 	for tag, value := range params {
 		transform.Set(tag, value)
 	}
 	return transform
 }
 
-func (style *viewStyle) setTransform(value any) bool {
+func (transform *transformData) init() {
+	transform.dataProperty.init()
+	transform.set = transformSet
+	transform.supportedProperties = []PropertyName{
+		RotateX, RotateY, RotateZ, Rotate, SkewX, SkewY, ScaleX, ScaleY, ScaleZ,
+		Perspective, TranslateX, TranslateY, TranslateZ,
+	}
+}
+
+func (transform *transformData) String() string {
+	buffer := allocStringBuilder()
+	defer freeStringBuilder(buffer)
+	transform.writeString(buffer, "")
+	return buffer.String()
+}
+
+func (transform *transformData) writeString(buffer *strings.Builder, indent string) {
+	buffer.WriteString("_{ ")
+	comma := false
+	for _, tag := range transform.supportedProperties {
+		if value, ok := transform.properties[tag]; ok {
+			if comma {
+				buffer.WriteString(", ")
+			}
+			buffer.WriteString(string(tag))
+			buffer.WriteString(" = ")
+			writePropertyValue(buffer, tag, value, indent)
+			comma = true
+		}
+	}
+	buffer.WriteString(" }")
+}
+
+func transformSet(properties Properties, tag PropertyName, value any) []PropertyName {
+	switch tag {
+
+	case RotateX, RotateY, RotateZ:
+		return setFloatProperty(properties, tag, value, 0, 1)
+
+	case Rotate, SkewX, SkewY:
+		return setAngleProperty(properties, tag, value)
+
+	case ScaleX, ScaleY, ScaleZ:
+		return setFloatProperty(properties, tag, value, -math.MaxFloat64, math.MaxFloat64)
+
+	case Perspective, TranslateX, TranslateY, TranslateZ:
+		return setSizeProperty(properties, tag, value)
+	}
+
+	return nil
+}
+
+func setTransformProperty(properties Properties, value any) bool {
 
 	setObject := func(obj DataObject) bool {
 		transform := NewTransform(nil)
 		ok := true
 		for i := 0; i < obj.PropertyCount(); i++ {
 			if prop := obj.Property(i); prop.Type() == TextNode {
-				if !transform.Set(prop.Tag(), prop.Text()) {
+				if !transform.Set(PropertyName(prop.Tag()), prop.Text()) {
 					ok = false
 				}
 			} else {
@@ -428,17 +481,17 @@ func (style *viewStyle) setTransform(value any) bool {
 			}
 		}
 
-		if !ok && len(transform.AllTags()) == 0 {
+		if !ok && transform.empty() {
 			return false
 		}
 
-		style.properties[TransformTag] = transform
+		properties.setRaw(TransformTag, transform)
 		return true
 	}
 
 	switch value := value.(type) {
 	case Transform:
-		style.properties[TransformTag] = value
+		properties.setRaw(TransformTag, value)
 		return true
 
 	case DataObject:
@@ -462,8 +515,8 @@ func (style *viewStyle) setTransform(value any) bool {
 	return false
 }
 
-func (style *viewStyle) transformProperty() Transform {
+func getTransformProperty(properties Properties) Transform {
-	if val, ok := style.properties[TransformTag]; ok {
+	if val := properties.getRaw(TransformTag); val != nil {
 		if transform, ok := val.(Transform); ok {
 			return transform
 		}
@@ -471,80 +524,26 @@ func (style *viewStyle) transformProperty() Transform {
 	return nil
 }
 
-func (style *viewStyle) setTransformProperty(tag string, value any) bool {
+func setTransformPropertyElement(properties Properties, tag PropertyName, value any) []PropertyName {
 	switch tag {
-	case RotateX, RotateY, RotateZ, Rotate, SkewX, SkewY, ScaleX, ScaleY, ScaleZ, TranslateX, TranslateY, TranslateZ:
+	case Perspective, RotateX, RotateY, RotateZ, Rotate, SkewX, SkewY, ScaleX, ScaleY, ScaleZ, TranslateX, TranslateY, TranslateZ:
-		if transform := style.transformProperty(); transform != nil {
+		if transform := getTransformProperty(properties); transform != nil {
-			return transform.Set(tag, value)
+			if result := transformSet(transform, tag, value); result != nil {
+				result = append(result, TransformTag)
 			}
-
+		} else {
 			transform := NewTransform(nil)
-		if !transform.Set(tag, value) {
+			if result := transformSet(transform, tag, value); result != nil {
-			return false
+				properties.setRaw(TransformTag, transform)
-		}
+				result = append(result, TransformTag)
-
+			}
-		style.properties[TransformTag] = transform
-		return true
 		}
 
+	default:
 		ErrorLogF(`"Transform" interface does not support the "%s" property`, tag)
-	return false
 	}
 
-func (transform *transformData) String() string {
+	return nil
-	buffer := allocStringBuilder()
-	defer freeStringBuilder(buffer)
-	transform.writeString(buffer, "")
-	return buffer.String()
-}
-
-func (transform *transformData) writeString(buffer *strings.Builder, indent string) {
-	buffer.WriteString("_{ ")
-	comma := false
-	for _, tag := range []string{SkewX, SkewY, TranslateX, TranslateY, TranslateZ,
-		ScaleX, ScaleY, ScaleZ, Rotate, RotateX, RotateY, RotateZ} {
-		if value, ok := transform.properties[tag]; ok {
-			if comma {
-				buffer.WriteString(", ")
-			}
-			buffer.WriteString(tag)
-			buffer.WriteString(" = ")
-			writePropertyValue(buffer, tag, value, indent)
-			comma = true
-		}
-	}
-	buffer.WriteString(" }")
-}
-
-func (transform *transformData) Set(tag string, value any) bool {
-	return transform.set(strings.ToLower(tag), value)
-}
-
-func (transform *transformData) set(tag string, value any) bool {
-	if value == nil {
-		_, exist := transform.properties[tag]
-		if exist {
-			delete(transform.properties, tag)
-		}
-		return exist
-	}
-
-	switch tag {
-
-	case RotateX, RotateY, RotateZ:
-		return transform.setFloatProperty(tag, value, 0, 1)
-
-	case Rotate, SkewX, SkewY:
-		return transform.setAngleProperty(tag, value)
-
-	case ScaleX, ScaleY, ScaleZ:
-		return transform.setFloatProperty(tag, value, -math.MaxFloat64, math.MaxFloat64)
-
-	case TranslateX, TranslateY, TranslateZ:
-		return transform.setSizeProperty(tag, value)
-	}
-
-	return false
 }
 
 func getTransform3D(style Properties, session Session) bool {
@@ -578,61 +577,75 @@ func (transform *transformData) getTranslate(session Session) (SizeUnit, SizeUni
 	return x, y, z
 }
 
-func (transform *transformData) transformCSS(session Session, transform3D bool) string {
+func (transform *transformData) transformCSS(session Session) string {
 
 	buffer := allocStringBuilder()
 	defer freeStringBuilder(buffer)
 
+	if perspective, ok := sizeProperty(transform, Perspective, session); ok && perspective.Type != Auto && perspective.Value != 0 {
+		buffer.WriteString(`perspective(`)
+		buffer.WriteString(perspective.cssString("0", session))
+		buffer.WriteString(") ")
+	}
+
 	skewX, skewY, skewOK := transform.getSkew(session)
 	if skewOK {
 		buffer.WriteString(`skew(`)
 		buffer.WriteString(skewX.cssString())
 		buffer.WriteRune(',')
 		buffer.WriteString(skewY.cssString())
-		buffer.WriteRune(')')
+		buffer.WriteString(") ")
 	}
 
 	x, y, z := transform.getTranslate(session)
+	if z.Type != Auto && z.Value != 0 {
 
-	scaleX, okScaleX := floatTextProperty(transform, ScaleX, session, 1)
-	scaleY, okScaleY := floatTextProperty(transform, ScaleY, session, 1)
-
-	if transform3D {
-		if x.Type != Auto || y.Type != Auto || z.Type != Auto {
-			if buffer.Len() > 0 {
-				buffer.WriteRune(' ')
-			}
 		buffer.WriteString(`translate3d(`)
 		buffer.WriteString(x.cssString("0", session))
 		buffer.WriteRune(',')
 		buffer.WriteString(y.cssString("0", session))
 		buffer.WriteRune(',')
 		buffer.WriteString(z.cssString("0", session))
-			buffer.WriteRune(')')
+		buffer.WriteString(") ")
+
+	} else if (x.Type != Auto && x.Value != 0) || (y.Type != Auto && y.Value != 0) {
+
+		buffer.WriteString(`translate(`)
+		buffer.WriteString(x.cssString("0", session))
+		buffer.WriteRune(',')
+		buffer.WriteString(y.cssString("0", session))
+		buffer.WriteString(") ")
 	}
 
+	scaleX, okScaleX := floatTextProperty(transform, ScaleX, session, 1)
+	scaleY, okScaleY := floatTextProperty(transform, ScaleY, session, 1)
 	scaleZ, okScaleZ := floatTextProperty(transform, ScaleZ, session, 1)
-		if okScaleX || okScaleY || okScaleZ {
+	if okScaleZ {
-			if buffer.Len() > 0 {
+
-				buffer.WriteRune(' ')
-			}
 		buffer.WriteString(`scale3d(`)
 		buffer.WriteString(scaleX)
 		buffer.WriteRune(',')
 		buffer.WriteString(scaleY)
 		buffer.WriteRune(',')
 		buffer.WriteString(scaleZ)
-			buffer.WriteRune(')')
+		buffer.WriteString(") ")
+
+	} else if okScaleX || okScaleY {
+
+		buffer.WriteString(`scale(`)
+		buffer.WriteString(scaleX)
+		buffer.WriteRune(',')
+		buffer.WriteString(scaleY)
+		buffer.WriteString(") ")
 	}
 
 	if angle, ok := angleProperty(transform, Rotate, session); ok {
-			rotateX, _ := floatTextProperty(transform, RotateX, session, 1)
+		rotateX, xOK := floatTextProperty(transform, RotateX, session, 1)
-			rotateY, _ := floatTextProperty(transform, RotateY, session, 1)
+		rotateY, yOK := floatTextProperty(transform, RotateY, session, 1)
-			rotateZ, _ := floatTextProperty(transform, RotateZ, session, 1)
+		rotateZ, zOK := floatTextProperty(transform, RotateZ, session, 1)
+
+		if xOK || yOK || zOK {
 
-			if buffer.Len() > 0 {
-				buffer.WriteRune(' ')
-			}
 			buffer.WriteString(`rotate3d(`)
 			buffer.WriteString(rotateX)
 			buffer.WriteRune(',')
@@ -641,53 +654,25 @@ func (transform *transformData) transformCSS(session Session, transform3D bool)
 			buffer.WriteString(rotateZ)
 			buffer.WriteRune(',')
 			buffer.WriteString(angle.cssString())
-			buffer.WriteRune(')')
+			buffer.WriteString(") ")
-		}
 
 		} else {
 
-		if x.Type != Auto || y.Type != Auto {
-			if buffer.Len() > 0 {
-				buffer.WriteRune(' ')
-			}
-			buffer.WriteString(`translate(`)
-			buffer.WriteString(x.cssString("0", session))
-			buffer.WriteRune(',')
-			buffer.WriteString(y.cssString("0", session))
-			buffer.WriteRune(')')
-		}
-
-		if okScaleX || okScaleY {
-			if buffer.Len() > 0 {
-				buffer.WriteRune(' ')
-			}
-			buffer.WriteString(`scale(`)
-			buffer.WriteString(scaleX)
-			buffer.WriteRune(',')
-			buffer.WriteString(scaleY)
-			buffer.WriteRune(')')
-		}
-
-		if angle, ok := angleProperty(transform, Rotate, session); ok {
-			if buffer.Len() > 0 {
-				buffer.WriteRune(' ')
-			}
 			buffer.WriteString(`rotate(`)
 			buffer.WriteString(angle.cssString())
-			buffer.WriteRune(')')
+			buffer.WriteString(") ")
 		}
 	}
 
-	return buffer.String()
+	length := buffer.Len()
+	if length == 0 {
+		return ""
+	}
+	result := buffer.String()
+	return result[:length-1]
 }
 
 func (style *viewStyle) writeViewTransformCSS(builder cssBuilder, session Session) {
-	transform3D := getTransform3D(style, session)
-	if transform3D {
-		if perspective, ok := sizeProperty(style, Perspective, session); ok && perspective.Type != Auto && perspective.Value != 0 {
-			builder.add(`perspective`, perspective.cssString("0", session))
-		}
-
 	x, y := getPerspectiveOrigin(style, session)
 	if x.Type != Auto || y.Type != Auto {
 		builder.addValues(`perspective-origin`, ` `, x.cssString("50%", session), y.cssString("50%", session))
@@ -702,29 +687,23 @@ func (style *viewStyle) writeViewTransformCSS(builder cssBuilder, session Sessio
 	}
 
 	x, y, z := getOrigin(style, session)
-		if x.Type != Auto || y.Type != Auto || z.Type != Auto {
+	if z.Type != Auto && z.Value != 0 {
 		builder.addValues(`transform-origin`, ` `, x.cssString("50%", session), y.cssString("50%", session), z.cssString("0", session))
-		}
+	} else if x.Type != Auto || y.Type != Auto {
-	} else {
-		x, y, _ := getOrigin(style, session)
-		if x.Type != Auto || y.Type != Auto {
 		builder.addValues(`transform-origin`, ` `, x.cssString("50%", session), y.cssString("50%", session))
 	}
-	}
 
-	if transform := style.transformProperty(); transform != nil {
+	if transform := getTransformProperty(style); transform != nil {
-		builder.add(`transform`, transform.transformCSS(session, transform3D))
+		builder.add(`transform`, transform.transformCSS(session))
 	}
 }
 
-func (view *viewData) updateTransformProperty(tag string) bool {
+/*
+func (view *viewData) updateTransformProperty(tag PropertyName) bool {
 	htmlID := view.htmlID()
 	session := view.session
 
 	switch tag {
-	case Perspective:
-		updateCSSStyle(htmlID, session)
-
 	case PerspectiveOriginX, PerspectiveOriginY:
 		if getTransform3D(view, session) {
 			x, y := GetPerspectiveOrigin(view)
@@ -738,31 +717,27 @@ func (view *viewData) updateTransformProperty(tag string) bool {
 	case BackfaceVisible:
 		if getTransform3D(view, session) {
 			if GetBackfaceVisible(view) {
-				session.updateCSSProperty(htmlID, BackfaceVisible, "visible")
+				session.updateCSSProperty(htmlID, string(BackfaceVisible), "visible")
 			} else {
-				session.updateCSSProperty(htmlID, BackfaceVisible, "hidden")
+				session.updateCSSProperty(htmlID, string(BackfaceVisible), "hidden")
 			}
 		}
 
 	case OriginX, OriginY, OriginZ:
 		x, y, z := getOrigin(view, session)
 		value := ""
-		if getTransform3D(view, session) {
+
-			if x.Type != Auto || y.Type != Auto || z.Type != Auto {
+		if z.Type != Auto {
 			value = x.cssString("50%", session) + " " + y.cssString("50%", session) + " " + z.cssString("50%", session)
-			}
+		} else if x.Type != Auto || y.Type != Auto {
-		} else {
-			if x.Type != Auto || y.Type != Auto {
 			value = x.cssString("50%", session) + " " + y.cssString("50%", session)
 		}
-		}
 		session.updateCSSProperty(htmlID, "transform-origin", value)
 
 	case TransformTag, SkewX, SkewY, TranslateX, TranslateY, TranslateZ,
 		ScaleX, ScaleY, ScaleZ, Rotate, RotateX, RotateY, RotateZ:
-		if transform := view.transformProperty(); transform != nil {
+		if transform := getTransformProperty(view); transform != nil {
-			transform3D := getTransform3D(view, session)
+			session.updateCSSProperty(htmlID, "transform", transform.transformCSS(session))
-			session.updateCSSProperty(htmlID, "transform", transform.transformCSS(session, transform3D))
 		} else {
 			session.updateCSSProperty(htmlID, "transform", "")
 		}
@@ -773,3 +748,4 @@ func (view *viewData) updateTransformProperty(tag string) bool {
 
 	return true
 }
+*/

viewUtils.go

@@ -3,7 +3,7 @@ package rui
 // Get returns a value of the property with name "tag" of the "rootView" subview with "viewID" id value.
 // The type of return value depends on the property.
 // If the subview don't exists or the property is not set then nil is returned.
-func Get(rootView View, viewID, tag string) any {
+func Get(rootView View, viewID string, tag PropertyName) any {
 	var view View
 	if viewID != "" {
 		view = ViewByID(rootView, viewID)
@@ -19,7 +19,7 @@ func Get(rootView View, viewID, tag string) any {
 // Set sets the property with name "tag" of the "rootView" subview with "viewID" id by value. Result:
 // true - success,
 // false - error (incompatible type or invalid format of a string value, see AppLog).
-func Set(rootView View, viewID, tag string, value any) bool {
+func Set(rootView View, viewID string, tag PropertyName, value any) bool {
 	var view View
 	if viewID != "" {
 		view = ViewByID(rootView, viewID)
@@ -34,7 +34,7 @@ func Set(rootView View, viewID, tag string, value any) bool {
 
 // SetChangeListener sets a listener for changing a subview property value.
 // If the second argument (subviewID) is not specified or it is "" then a listener for the first argument (view) is set
-func SetChangeListener(view View, viewID, tag string, listener func(View, string)) {
+func SetChangeListener(view View, viewID string, tag PropertyName, listener func(View, PropertyName)) {
 	if viewID != "" {
 		view = ViewByID(view, viewID)
 	}
@@ -294,7 +294,7 @@ func GetBorder(view View, subviewID ...string) ViewBorders {
 		view = ViewByID(view, subviewID[0])
 	}
 	if view != nil {
-		if border := getBorder(view, Border); border != nil {
+		if border := getBorderProperty(view, Border); border != nil {
 			return border.ViewBorders(view.Session())
 		}
 	}
@@ -320,7 +320,7 @@ func GetOutline(view View, subviewID ...string) ViewOutline {
 		view = ViewByID(view, subviewID[0])
 	}
 	if view != nil {
-		if outline := getOutline(view); outline != nil {
+		if outline := getOutlineProperty(view); outline != nil {
 			return outline.ViewOutline(view.Session())
 		}
 	}
@@ -706,9 +706,9 @@ func GetNotTranslate(view View, subviewID ...string) bool {
 	return boolStyledProperty(view, subviewID, NotTranslate, true)
 }
 
-func valueFromStyle(view View, tag string) any {
+func valueFromStyle(view View, tag PropertyName) any {
 	session := view.Session()
-	getValue := func(styleTag string) any {
+	getValue := func(styleTag PropertyName) any {
 		if style, ok := stringProperty(view, styleTag, session); ok {
 			if style, ok := session.resolveConstants(style); ok {
 				return session.styleProperty(style, tag)
@@ -725,7 +725,7 @@ func valueFromStyle(view View, tag string) any {
 	return getValue(Style)
 }
 
-func sizeStyledProperty(view View, subviewID []string, tag string, inherit bool) SizeUnit {
+func sizeStyledProperty(view View, subviewID []string, tag PropertyName, inherit bool) SizeUnit {
 	if len(subviewID) > 0 && subviewID[0] != "" {
 		view = ViewByID(view, subviewID[0])
 	}
@@ -749,7 +749,7 @@ func sizeStyledProperty(view View, subviewID []string, tag string, inherit bool)
 	return AutoSize()
 }
 
-func enumStyledProperty(view View, subviewID []string, tag string, defaultValue int, inherit bool) int {
+func enumStyledProperty(view View, subviewID []string, tag PropertyName, defaultValue int, inherit bool) int {
 	if len(subviewID) > 0 && subviewID[0] != "" {
 		view = ViewByID(view, subviewID[0])
 	}
@@ -773,7 +773,7 @@ func enumStyledProperty(view View, subviewID []string, tag string, defaultValue
 	return defaultValue
 }
 
-func boolStyledProperty(view View, subviewID []string, tag string, inherit bool) bool {
+func boolStyledProperty(view View, subviewID []string, tag PropertyName, inherit bool) bool {
 	if len(subviewID) > 0 && subviewID[0] != "" {
 		view = ViewByID(view, subviewID[0])
 	}
@@ -798,7 +798,7 @@ func boolStyledProperty(view View, subviewID []string, tag string, inherit bool)
 	return false
 }
 
-func intStyledProperty(view View, subviewID []string, tag string, defaultValue int) int {
+func intStyledProperty(view View, subviewID []string, tag PropertyName, defaultValue int) int {
 	if len(subviewID) > 0 && subviewID[0] != "" {
 		view = ViewByID(view, subviewID[0])
 	}
@@ -815,7 +815,7 @@ func intStyledProperty(view View, subviewID []string, tag string, defaultValue i
 	return defaultValue
 }
 
-func floatStyledProperty(view View, subviewID []string, tag string, defaultValue float64) float64 {
+func floatStyledProperty(view View, subviewID []string, tag PropertyName, defaultValue float64) float64 {
 	if len(subviewID) > 0 && subviewID[0] != "" {
 		view = ViewByID(view, subviewID[0])
 	}
@@ -831,7 +831,7 @@ func floatStyledProperty(view View, subviewID []string, tag string, defaultValue
 	return defaultValue
 }
 
-func colorStyledProperty(view View, subviewID []string, tag string, inherit bool) Color {
+func colorStyledProperty(view View, subviewID []string, tag PropertyName, inherit bool) Color {
 	if len(subviewID) > 0 && subviewID[0] != "" {
 		view = ViewByID(view, subviewID[0])
 	}

viewsContainer.go

@@ -24,6 +24,8 @@ type ViewsContainer interface {
 
 	// ViewIndex returns the index of view, -1 overwise
 	ViewIndex(view View) int
+
+	setContent(value any) bool
 }
 
 type viewsContainerData struct {
@@ -36,10 +38,10 @@ func (container *viewsContainerData) init(session Session) {
 	container.viewData.init(session)
 	container.tag = "ViewsContainer"
 	container.views = []View{}
-}
+	container.getFunc = container.get
-
+	container.set = container.setFunc
-func (container *viewsContainerData) String() string {
+	container.remove = container.removeFunc
-	return getViewString(container, nil)
+	container.changed = viewsContainerPropertyChanged
 }
 
 func (container *viewsContainerData) setParentID(parentID string) {
@@ -62,6 +64,13 @@ func (container *viewsContainerData) Views() []View {
 	return []View{}
 }
 
+func viewsContainerContentChanged(container *viewsContainerData) {
+	updateInnerHTML(container.htmlID(), container.Session())
+	if listener, ok := container.changeListener[Content]; ok {
+		listener(container, Content)
+	}
+}
+
 // Append appends a view to the end of the list of a view children
 func (container *viewsContainerData) Append(view View) {
 	if view != nil {
@@ -72,8 +81,7 @@ func (container *viewsContainerData) Append(view View) {
 		} else {
 			container.views = append(container.views, view)
 		}
-		updateInnerHTML(container.htmlID(), container.session)
+		viewsContainerContentChanged(container)
-		container.propertyChangedEvent(Content)
 	}
 }
 
@@ -86,13 +94,11 @@ func (container *viewsContainerData) Insert(view View, index int) {
 		} else if index > 0 {
 			view.setParentID(htmlID)
 			container.views = append(container.views[:index], append([]View{view}, container.views[index:]...)...)
-			updateInnerHTML(container.htmlID(), container.session)
+			viewsContainerContentChanged(container)
-			container.propertyChangedEvent(Content)
 		} else {
 			view.setParentID(htmlID)
 			container.views = append([]View{view}, container.views...)
-			updateInnerHTML(container.htmlID(), container.session)
+			viewsContainerContentChanged(container)
-			container.propertyChangedEvent(Content)
 		}
 	}
 }
@@ -119,8 +125,7 @@ func (container *viewsContainerData) RemoveView(index int) View {
 	}
 
 	view.setParentID("")
-	updateInnerHTML(container.htmlID(), container.session)
+	viewsContainerContentChanged(container)
-	container.propertyChangedEvent(Content)
 	return view
 }
 
@@ -158,67 +163,60 @@ func viewFromTextValue(text string, session Session) View {
 	return NewTextView(session, Params{Text: text})
 }
 
-func (container *viewsContainerData) Remove(tag string) {
+func (container *viewsContainerData) removeFunc(view View, tag PropertyName) []PropertyName {
-	container.remove(strings.ToLower(tag))
-}
-
-func (container *viewsContainerData) remove(tag string) {
 	switch tag {
 	case Content:
-		if container.views == nil || len(container.views) > 0 {
+		if len(container.views) > 0 {
 			container.views = []View{}
-			updateInnerHTML(container.htmlID(), container.Session())
+			return []PropertyName{tag}
 		}
-		container.propertyChangedEvent(Content)
+		return []PropertyName{}
 
 	case Disabled:
-		if _, ok := container.properties[Disabled]; ok {
+		if view.getRaw(Disabled) != nil {
-			delete(container.properties, Disabled)
+			view.setRaw(Disabled, nil)
-			if container.views != nil {
 			for _, view := range container.views {
 				view.Remove(Disabled)
 			}
+			return []PropertyName{tag}
 		}
-			container.propertyChangedEvent(tag)
+	}
-		}
+	return viewRemove(view, tag)
-
-	default:
-		container.viewData.remove(tag)
-	}
-}
-
-func (container *viewsContainerData) Set(tag string, value any) bool {
-	return container.set(strings.ToLower(tag), value)
-}
-
-func (container *viewsContainerData) set(tag string, value any) bool {
-	if value == nil {
-		container.remove(tag)
-		return true
 }
 
+func (container *viewsContainerData) setFunc(self View, tag PropertyName, value any) []PropertyName {
 	switch tag {
 	case Content:
-		return container.setContent(value)
+		if container.setContent(value) {
+			return []PropertyName{tag}
+		}
+		return nil
 
 	case Disabled:
 		oldDisabled := IsDisabled(container)
-		if container.viewData.Set(Disabled, value) {
+		result := viewSet(self, Disabled, value)
+		if result != nil {
 			disabled := IsDisabled(container)
 			if oldDisabled != disabled {
-				if container.views != nil {
 				for _, view := range container.views {
 					view.Set(Disabled, disabled)
 				}
 			}
 		}
-			container.propertyChangedEvent(tag)
+		return result
-			return true
-		}
-		return false
 	}
 
-	return container.viewData.set(tag, value)
+	return viewSet(self, tag, value)
+}
+
+func viewsContainerPropertyChanged(view View, tag PropertyName) {
+	switch tag {
+	case Content:
+		updateInnerHTML(view.htmlID(), view.Session())
+
+	default:
+		viewPropertyChanged(view, tag)
+	}
 }
 
 func (container *viewsContainerData) setContent(value any) bool {
@@ -291,25 +289,16 @@ func (container *viewsContainerData) setContent(value any) bool {
 		}
 	}
 
-	if container.created {
-		updateInnerHTML(htmlID, container.session)
-	}
-
-	container.propertyChangedEvent(Content)
 	return true
 }
 
-func (container *viewsContainerData) Get(tag string) any {
+func (container *viewsContainerData) get(view View, tag PropertyName) any {
-	return container.get(strings.ToLower(tag))
-}
-
-func (container *viewsContainerData) get(tag string) any {
 	switch tag {
 	case Content:
 		return container.views
 
 	default:
-		return container.viewData.get(tag)
+		return viewGet(view, tag)
 	}
 }