Changed the main DropDownList and EditView listener

README-ru.md

@@ -3107,13 +3107,21 @@ string свойство "edit-view-pattern" (константа EditViewPattern)
 Для отслеживания изменения текста используется событие "edit-text-changed" (константа
 EditTextChangedEvent). Основной слушатель события имеет следующий формат:
 
-	func(EditView, string)
+	func(EditView, string, string)
 
-где второй аргумент это новое значение текста
+где второй аргумент это новое значение текста, третий аргумент - предыдущее значение текста.
+
+Дополнительные слушатели события могут иметь следующий формат
+
+	func(EditView, newText string)
+	func(newText, oldText string)
+	func(newText string)
+	func(EditView)
+	func()
 
 Получить текущий список слушателей изменения текста можно с помощью функции
 
-	func GetTextChangedListeners(view View, subviewID ...string) []func(EditView, string)
+	func GetTextChangedListeners(view View, subviewID ...string) []func(EditView, string, string)
 
 ## NumberPicker
 
@@ -3425,13 +3433,21 @@ float32, float64, int, int8…int64, uint, uint8…uint64.
 Для отслеживания изменения свойства "current" используется событие "drop-down-event" (константа
 DropDownEvent). Основной слушатель события имеет следующий формат:
 
-	func(list DropDownList, newCurrent int)
+	func(list DropDownList, newCurrent, oldCurrent int)
 
-где второй аргумент это индекс выбранного элемента
+где второй аргумент это индекс выбранного элемента, третий аргумент - предыдущее значение индекса.
+
+Дополнительные слушатели события могут иметь следующий формат
+
+	func(list DropDownList, newCurrent int)
+	func(newCurrent, oldCurrent int)
+	func(newCurrent int)
+	func(list DropDownList)
+	func()
 
 Получить текущий список слушателей изменения даты можно с помощью функции
 
-	func GetDropDownListeners(view View, subviewID ...string) []func(DropDownList, int)
+	func GetDropDownListeners(view View, subviewID ...string) []func(DropDownList, int, int)
 
 ## ProgressBar
 

README.md

@@ -3071,13 +3071,21 @@ The following functions can be used to get the values of the properties of an Ed
 The "edit-text-changed" event (EditTextChangedEvent constant) is used to track changes to the text. 
 The main event listener has the following format:
 
-	func(EditView, string)
+	func(EditView, string, string)
 
-where the second argument is the new text value
+where the second argument is the new text value the third argument is the previous text value.
+
+Additional event listeners can have the following format
+
+	func(EditView, newText string)
+	func(newText, oldText string)
+	func(newText string)
+	func(EditView)
+	func()
 
 You can get the current list of text change listeners using the function
 
-	func GetTextChangedListeners(view View, subviewID ...string) []func(EditView, string)
+	func GetTextChangedListeners(view View, subviewID ...string) []func(EditView, string, string)
 
 ## NumberPicker
 
@@ -3393,11 +3401,19 @@ The main event listener has the following format:
 
 	func(list DropDownList, newCurrent int)
 
-where the second argument is the index of the selected item
+where the second argument is the index of the selected item, the third argument is the previous index value.
+
+Additional event listeners can have the following format
+
+	func(list DropDownList, newCurrent int)
+	func(newCurrent, oldCurrent int)
+	func(newCurrent int)
+	func(list DropDownList)
+	func()
 
 You can get the current list of date change listeners using the function
 
-	func GetDropDownListeners(view View, subviewID ...string) []func(DropDownList, int)
+	func GetDropDownListeners(view View, subviewID ...string) []func(DropDownList, int, int)
 
 ## ProgressBar
 

dropDownList.go

@@ -21,7 +21,7 @@ type dropDownListData struct {
 	viewData
 	items            []string
 	disabledItems    []any
-	dropDownListener []func(DropDownList, int)
+	dropDownListener []func(DropDownList, int, int)
 }
 
 // NewDropDownList create new DropDownList object and return it
@@ -41,7 +41,7 @@ func (list *dropDownListData) init(session Session) {
 	list.tag = "DropDownList"
 	list.items = []string{}
 	list.disabledItems = []any{}
-	list.dropDownListener = []func(DropDownList, int){}
+	list.dropDownListener = []func(DropDownList, int, int){}
 }
 
 func (list *dropDownListData) String() string {
@@ -78,7 +78,7 @@ func (list *dropDownListData) remove(tag string) {
 
 	case DropDownEvent:
 		if len(list.dropDownListener) > 0 {
-			list.dropDownListener = []func(DropDownList, int){}
+			list.dropDownListener = []func(DropDownList, int, int){}
 			list.propertyChangedEvent(tag)
 		}
 
@@ -89,7 +89,7 @@ func (list *dropDownListData) remove(tag string) {
 			if list.created {
 				list.session.callFunc("selectDropDownListItem", list.htmlID(), 0)
 			}
-			list.onSelectedItemChanged(0)
+			list.onSelectedItemChanged(0, oldCurrent)
 		}
 
 	default:
@@ -116,12 +116,12 @@ func (list *dropDownListData) set(tag string, value any) bool {
 		return list.setDisabledItems(value)
 
 	case DropDownEvent:
-		listeners, ok := valueToEventListeners[DropDownList, int](value)
+		listeners, ok := valueToEventWithOldListeners[DropDownList, int](value)
 		if !ok {
 			notCompatibleType(tag, value)
 			return false
 		} else if listeners == nil {
-			listeners = []func(DropDownList, int){}
+			listeners = []func(DropDownList, int, int){}
 		}
 		list.dropDownListener = listeners
 		list.propertyChangedEvent(tag)
@@ -137,7 +137,7 @@ func (list *dropDownListData) set(tag string, value any) bool {
 			if list.created {
 				list.session.callFunc("selectDropDownListItem", list.htmlID(), current)
 			}
-			list.onSelectedItemChanged(current)
+			list.onSelectedItemChanged(current, oldCurrent)
 		}
 		return true
 	}
@@ -377,9 +377,9 @@ func (list *dropDownListData) htmlDisabledProperties(self View, buffer *strings.
 	}
 }
 
-func (list *dropDownListData) onSelectedItemChanged(number int) {
+func (list *dropDownListData) onSelectedItemChanged(number, old int) {
 	for _, listener := range list.dropDownListener {
-		listener(list, number)
+		listener(list, number, old)
 	}
 	list.propertyChangedEvent(Current)
 }
@@ -390,8 +390,9 @@ func (list *dropDownListData) handleCommand(self View, command string, data Data
 		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) {
+					old := GetCurrent(list)
 					list.properties[Current] = number
-					list.onSelectedItemChanged(number)
+					list.onSelectedItemChanged(number, old)
 				}
 			} else {
 				ErrorLog(err.Error())
@@ -406,8 +407,8 @@ func (list *dropDownListData) handleCommand(self View, command string, data Data
 
 // GetDropDownListeners returns the "drop-down-event" listener 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 GetDropDownListeners(view View, subviewID ...string) []func(DropDownList, int) {
+func GetDropDownListeners(view View, subviewID ...string) []func(DropDownList, int, int) {
-	return getEventListeners[DropDownList, int](view, subviewID, DropDownEvent)
+	return getEventWithOldListeners[DropDownList, int](view, subviewID, DropDownEvent)
 }
 
 // GetDropDownItems return the DropDownList items list.

editView.go

@@ -41,7 +41,7 @@ type EditView interface {
 
 type editViewData struct {
 	viewData
-	textChangeListeners []func(EditView, string)
+	textChangeListeners []func(EditView, string, string)
 }
 
 // NewEditView create new EditView object and return it
@@ -58,7 +58,7 @@ func newEditView(session Session) View {
 
 func (edit *editViewData) init(session Session) {
 	edit.viewData.init(session)
-	edit.textChangeListeners = []func(EditView, string){}
+	edit.textChangeListeners = []func(EditView, string, string){}
 	edit.tag = "EditView"
 }
 
@@ -125,7 +125,7 @@ func (edit *editViewData) remove(tag string) {
 
 	case EditTextChangedEvent:
 		if len(edit.textChangeListeners) > 0 {
-			edit.textChangeListeners = []func(EditView, string){}
+			edit.textChangeListeners = []func(EditView, string, string){}
 			edit.propertyChangedEvent(tag)
 		}
 
@@ -134,7 +134,7 @@ func (edit *editViewData) remove(tag string) {
 			oldText := GetText(edit)
 			delete(edit.properties, tag)
 			if oldText != "" {
-				edit.textChanged("")
+				edit.textChanged("", oldText)
 				if edit.created {
 					edit.session.callFunc("setInputValue", edit.htmlID(), "")
 				}
@@ -205,7 +205,7 @@ func (edit *editViewData) set(tag string, value any) bool {
 		if text, ok := value.(string); ok {
 			edit.properties[Text] = text
 			if text = GetText(edit); oldText != text {
-				edit.textChanged(text)
+				edit.textChanged(text, oldText)
 				if edit.created {
 					if GetEditViewType(edit) == MultiLineText {
 						updateInnerHTML(edit.htmlID(), edit.Session())
@@ -328,12 +328,12 @@ func (edit *editViewData) set(tag string, value any) bool {
 		return false
 
 	case EditTextChangedEvent:
-		listeners, ok := valueToEventListeners[EditView, string](value)
+		listeners, ok := valueToEventWithOldListeners[EditView, string](value)
 		if !ok {
 			notCompatibleType(tag, value)
 			return false
 		} else if listeners == nil {
-			listeners = []func(EditView, string){}
+			listeners = []func(EditView, string, string){}
 		}
 		edit.textChangeListeners = listeners
 		edit.propertyChangedEvent(tag)
@@ -358,10 +358,11 @@ func (edit *editViewData) AppendText(text string) {
 	if GetEditViewType(edit) == MultiLineText {
 		if value := edit.getRaw(Text); value != nil {
 			if textValue, ok := value.(string); ok {
+				oldText := textValue
 				textValue += text
 				edit.properties[Text] = textValue
 				edit.session.callFunc("appendToInnerHTML", edit.htmlID(), text)
-				edit.textChanged(textValue)
+				edit.textChanged(textValue, oldText)
 				return
 			}
 		}
@@ -371,9 +372,9 @@ func (edit *editViewData) AppendText(text string) {
 	}
 }
 
-func (edit *editViewData) textChanged(newText string) {
+func (edit *editViewData) textChanged(newText, oldText string) {
 	for _, listener := range edit.textChangeListeners {
-		listener(edit, newText)
+		listener(edit, newText, oldText)
 	}
 	edit.propertyChangedEvent(Text)
 }
@@ -485,7 +486,7 @@ func (edit *editViewData) handleCommand(self View, command string, data DataObje
 		if text, ok := data.PropertyValue("text"); ok {
 			edit.properties[Text] = text
 			if text := GetText(edit); text != oldText {
-				edit.textChanged(text)
+				edit.textChanged(text, oldText)
 			}
 		}
 		return true
@@ -552,8 +553,8 @@ func IsSpellcheck(view View, subviewID ...string) bool {
 // GetTextChangedListeners returns the TextChangedListener list of an EditView or MultiLineEditView subview.
 // 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 GetTextChangedListeners(view View, subviewID ...string) []func(EditView, string) {
+func GetTextChangedListeners(view View, subviewID ...string) []func(EditView, string, string) {
-	return getEventListeners[EditView, string](view, subviewID, EditTextChangedEvent)
+	return getEventWithOldListeners[EditView, string](view, subviewID, EditTextChangedEvent)
 }
 
 // GetEditViewType returns a value of the Type property of EditView.

keyEvents.go

@@ -193,6 +193,185 @@ func valueToEventListeners[V View, E any](value any) ([]func(V, E), bool) {
 	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
+}
+
 var keyEvents = map[string]struct{ jsEvent, jsFunc string }{
 	KeyDownEvent: {jsEvent: "onkeydown", jsFunc: "keyDownEvent"},
 	KeyUpEvent:   {jsEvent: "onkeyup", jsFunc: "keyUpEvent"},
@@ -227,6 +406,19 @@ 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])