Added "disabled-items" property to DropDownList

README-ru.md

@@ -3001,6 +3001,21 @@ float32, float64, int, int8…int64, uint, uint8…uint64.
 
 	func GetDropDownItems(view View, subviewID string) []string
 
+Можно запретить выбор отдельных пунктов. Для этого используется свойство "disabled-items" (константа DisabledItems).
+Данному свойству присваивается массив индексов запрещенных пунктов. Индекс может задаваться или числом или в виде текста
+или как константа. Поэтому свойству "disabled-items" могут присваиваться следующие типы данных:
+
+* []int
+* int
+* []string
+* string может содержать несколько индексов разделенных запятыми
+* []interface{} содержащий в качестве элементов только: string, int, int8…int64, uint, uint8…uint64.
+
+Все эти типы данных преопразуются в []interface{} и присваиваются свойству "disabled-items".
+Прочитать значение свойства "disabled-items" можно с помощью функции
+
+	func GetDropDownDisabledItems(view View, subviewID string) []int
+
 Выбранное значение определяется int свойством "current" (константа Current). Значение по умолчанию 0.
 Прочитать значение данного свойства можно с помощью функции
 

README.md

@@ -2972,6 +2972,20 @@ You can read the value of the "items" property using the function
 
 	func GetDropDownItems(view View, subviewID string) []string
 
+You can disable the selection of individual items. For this, the "disabled-items" property (constant DisabledItems) is used.
+This property is assigned an array of disabled item indices. The index can be specified either as a number, as text, or as a constant. Therefore, the following data types can be assigned to the "disabled-items" property:
+
+* []int
+* int
+* []string
+* string - can contain multiple indexes separated by commas
+* []interface{} - containing as elements only: string, int, int8…int64, uint, uint8…uint64.
+
+All of these data types are converted to []interface{} and assigned to the "disabled-items" property.
+You can read the value of the "disabled-items" property using the function
+
+	func GetDropDownDisabledItems(view View, subviewID string) []int
+
 The selected value is determined by the int property "current" (Current constant). The default is 0.
 You can read the value of this property using the function
 

dropDownList.go

@@ -17,6 +17,7 @@ type DropDownList interface {
 type dropDownListData struct {
 	viewData
 	items            []string
+	disabledItems    []interface{}
 	dropDownListener []func(DropDownList, int)
 }
 
@@ -36,6 +37,7 @@ func (list *dropDownListData) Init(session Session) {
 	list.viewData.Init(session)
 	list.tag = "DropDownList"
 	list.items = []string{}
+	list.disabledItems = []interface{}{}
 	list.dropDownListener = []func(DropDownList, int){}
 }
 
@@ -58,6 +60,15 @@ func (list *dropDownListData) remove(tag string) {
 			list.propertyChangedEvent(tag)
 		}
 
+	case DisabledItems:
+		if len(list.disabledItems) > 0 {
+			list.disabledItems = []interface{}{}
+			if list.created {
+				updateInnerHTML(list.htmlID(), list.session)
+			}
+			list.propertyChangedEvent(tag)
+		}
+
 	case DropDownEvent:
 		if len(list.dropDownListener) > 0 {
 			list.dropDownListener = []func(DropDownList, int){}
@@ -85,10 +96,18 @@ func (list *dropDownListData) Set(tag string, value interface{}) bool {
 }
 
 func (list *dropDownListData) set(tag string, value interface{}) bool {
+	if value == nil {
+		list.remove(tag)
+		return true
+	}
+
 	switch tag {
 	case Items:
 		return list.setItems(value)
 
+	case DisabledItems:
+		return list.setDisabledItems(value)
+
 	case DropDownEvent:
 		return list.setDropDownListener(value)
 
@@ -119,7 +138,7 @@ func (list *dropDownListData) setItems(value interface{}) bool {
 		list.items = value
 
 	case []DataValue:
-		list.items = []string{}
+		list.items = make([]string, 0, len(value))
 		for _, val := range value {
 			if !val.IsObject() {
 				list.items = append(list.items, val.Value())
@@ -133,7 +152,7 @@ func (list *dropDownListData) setItems(value interface{}) bool {
 		}
 
 	case []interface{}:
-		items := []string{}
+		items := make([]string, 0, len(value))
 		for _, v := range value {
 			switch val := v.(type) {
 			case string:
@@ -183,6 +202,91 @@ func (list *dropDownListData) setItems(value interface{}) bool {
 	return true
 }
 
+func (list *dropDownListData) setDisabledItems(value interface{}) bool {
+	switch value := value.(type) {
+	case []int:
+		list.disabledItems = make([]interface{}, len(value))
+		for i, n := range value {
+			list.disabledItems[i] = n
+		}
+
+	case []interface{}:
+		disabledItems := make([]interface{}, len(value))
+		for i, val := range value {
+			if val == nil {
+				notCompatibleType(DisabledItems, value)
+				return false
+			}
+
+			switch val := val.(type) {
+			case string:
+				if isConstantName(val) {
+					disabledItems[i] = val
+				} else {
+					n, err := strconv.Atoi(val)
+					if err != nil {
+						notCompatibleType(DisabledItems, value)
+						return false
+					}
+					disabledItems[i] = n
+				}
+			default:
+				if n, ok := isInt(val); ok {
+					disabledItems[i] = n
+				} else {
+					notCompatibleType(DisabledItems, value)
+					return false
+				}
+			}
+
+		}
+		list.disabledItems = disabledItems
+
+	case string:
+		values := strings.Split(value, ",")
+		disabledItems := make([]interface{}, len(values))
+		for i, str := range values {
+			str = strings.Trim(str, " ")
+			if str == "" {
+				notCompatibleType(DisabledItems, value)
+				return false
+			}
+			if isConstantName(str) {
+				disabledItems[i] = str
+			} else {
+				n, err := strconv.Atoi(str)
+				if err != nil {
+					notCompatibleType(DisabledItems, value)
+					return false
+				}
+				disabledItems[i] = n
+			}
+		}
+		list.disabledItems = disabledItems
+
+	case []DataValue:
+		disabledItems := make([]string, 0, len(value))
+		for _, val := range value {
+			if !val.IsObject() {
+				disabledItems = append(disabledItems, val.Value())
+			}
+		}
+		return list.setDisabledItems(disabledItems)
+
+	default:
+		notCompatibleType(DisabledItems, value)
+		return false
+	}
+
+	if list.created {
+		updateInnerHTML(list.htmlID(), list.session)
+	}
+
+	list.propertyChangedEvent(Items)
+	return true
+
+}
+
 func (list *dropDownListData) setDropDownListener(value interface{}) bool {
 	switch value := value.(type) {
 	case func(DropDownList, int):
@@ -250,6 +354,9 @@ func (list *dropDownListData) get(tag string) interface{} {
 	case Items:
 		return list.items
 
+	case DisabledItems:
+		return list.disabledItems
+
 	case Current:
 		result, _ := intProperty(list, Current, list.session, 0)
 		return result
@@ -273,8 +380,19 @@ func (list *dropDownListData) htmlSubviews(self View, buffer *strings.Builder) {
 	if list.items != nil {
 		current := GetCurrent(list, "")
 		notTranslate := GetNotTranslate(list, "")
+		disabledItems := GetDropDownDisabledItems(list, "")
 		for i, item := range list.items {
-			if i == current {
+			disabled := false
+			for _, index := range disabledItems {
+				if i == index {
+					disabled = true
+					break
+				}
+			}
+
+			if disabled {
+				buffer.WriteString("<option disabled>")
+			} else if i == current {
 				buffer.WriteString("<option selected>")
 			} else {
 				buffer.WriteString("<option>")
@@ -349,3 +467,37 @@ func GetDropDownItems(view View, subviewID string) []string {
 	}
 	return []string{}
 }
+
+// func GetDropDownDisabledItems return the list of disabled item indexes
+func GetDropDownDisabledItems(view View, subviewID string) []int {
+	if subviewID != "" {
+		view = ViewByID(view, subviewID)
+	}
+	if view != nil {
+		if value := view.Get(DisabledItems); value != nil {
+			if values, ok := value.([]interface{}); ok {
+				count := len(values)
+				if count > 0 {
+					result := make([]int, 0, count)
+					for _, value := range values {
+						switch value := value.(type) {
+						case int:
+							result = append(result, value)
+
+						case string:
+							if value != "" && value[0] == '@' {
+								if val, ok := view.Session().Constant(value[1:]); ok {
+									if n, err := strconv.Atoi(val); err == nil {
+										result = append(result, n)
+									}
+								}
+							}
+						}
+					}
+					return result
+				}
+			}
+		}
+	}
+	return []int{}
+}

propertyNames.go

@@ -328,6 +328,8 @@ const (
 	Content = "content"
 	// Items is the constant for the "items" property tag.
 	Items = "items"
+	// DisabledItems is the constant for the "disabled-items" property tag.
+	DisabledItems = "disabled-items"
 	// Current is the constant for the "current" property tag.
 	Current = "current"
 	// Type is the constant for the "type" property tag.