Flex - SkinnableContainer

Introduction

The SkinnableContainer class is the base class for all the skinnable containers that have visual content.

Class Declaration

Following is the declaration for spark.components.SkinnableContainer class −

public class SkinnableContainer
   extends SkinnableContainerBase
      implements IDeferredContentOwner, IVisualElementContainer

Public Properties

Sr.No	Property & Description
1	autoLayout : Boolean If true, measurement and layout are done when the position or size of a child is changed.
2	creationPolicy : String Content creation policy for this component.
3	deferredContentCreated : Boolean [read-only] Contains true if deferred content has been created.
4	layout : LayoutBase The layout object for this container.
5	mxmlContent : Array [write-only] The visual content children for this Group.
6	mxmlContentFactory : IDeferredInstance [write-only] A factory object that creates the initial value for the content property.
7	numElements : int [read-only] The number of visual elements in this container.

Public Methods

Sr.No	Method & Description
1	SkinnableContainer() Constructor.
2	addElement(element:IVisualElement):IVisualElement Adds a visual element to this container.
3	addElementAt(element:IVisualElement, index:int):IVisualElement Adds a visual element to this container.
4	createDeferredContent():void Create the content for this component.
5	getElementAt(index:int):IVisualElement Returns the visual element at the specified index.
6	getElementIndex(element:IVisualElement):int Returns the index position of a visual element.
7	removeAllElements():void Removes all visual elements from the container.
8	removeElement(element:IVisualElement):IVisualElement Removes the specified visual element from the child list of this container.
9	removeElementAt(index:int):IVisualElement Removes a visual element from the specified index position in the container.
10	setElementIndex(element:IVisualElement, index:int):void Changes the position of an existing visual element in the visual container.
11	swapElements(element1:IVisualElement, element2:IVisualElement):void Swaps the index of the two specified visual elements.
12	swapElementsAt(index1:int, index2:int):void Swaps the visual elements at the two specified index positions in the container.

Protected Methods

Sr.No	Method & Description
1	createChildren():void [override] Create content children, if the creationPolicy property is not equal to none.
2	partAdded(partName:String, instance:Object):void [override] Called when a skin part is added.
3	partRemoved(partName:String, instance:Object):void [override] Called when an instance of a skin part is being removed.

Sr.No

Method & Description

createChildren():void

[override] Create content children, if the creationPolicy property is not equal to none.

partAdded(partName:String, instance:Object):void

[override] Called when a skin part is added.

partRemoved(partName:String, instance:Object):void

[override] Called when an instance of a skin part is being removed.

Events

Sr.No	Event & Description
1	contentCreationComplete Dispatched after the content for this component has been created.
2	elementAdd Dispatched when a visual element is added to the content holder.
3	elementRemove Dispatched when a visual element is removed from the content holder.

Sr.No

Event & Description

contentCreationComplete

Dispatched after the content for this component has been created.

elementAdd

Dispatched when a visual element is added to the content holder.

elementRemove

Dispatched when a visual element is removed from the content holder.

Methods Inherited

This class inherits methods from the following classes −

spark.components.supportClasses.SkinnableContainerBase
mx.core.UIComponent
mx.core.FlexSprite
flash.display.Sprite
flash.display.DisplayObjectContainer
flash.display.InteractiveObject
flash.display.DisplayObject
flash.events.EventDispatcher
Object

Flex SkinnableContainer Example

Let us follow the following steps to check usage of SkinnableContainer in a Flex application by creating a test application −

Step	Description
1	Create a project with a name HelloWorld under a packagecom.tutorialspoint.client as explained in the Flex - Create Application chapter.
2	Create a skin SkinnableContainerSkin for a host Component SkinnableContainerunder a package com.tutorialspoint.skin as explained in Flex - Style with skinchapter. Keep rest of the files unchanged.
3	Modify HelloWorld.mxml as explained below. Keep rest of the files unchanged.
4	Compile and run the application to make sure business logic is working as per the requirements.

Following is the content of the modified mxml file src/com.tutorialspoint/skin/SkinnableContainerSkin.mxml.

<?xml version = "1.0" encoding = "utf-8"?>
<s:Skin xmlns:fx = "http://ns.adobe.com/mxml/2009" 
   xmlns:s = "library://ns.adobe.com/flex/spark" 
   xmlns:fb = "http://ns.adobe.com/flashbuilder/2009" alpha.disabled = "0.5">
   
   <fx:Metadata>  
      <![CDATA[ 
         /** 
         * @copy spark.skins.spark.ApplicationSkin#hostComponent
         */
         [HostComponent("spark.components.SkinnableContainer")]
      ]]>
   </fx:Metadata> 
   
   <s:states>
      <s:State name = "normal" />
      <s:State name = "disabled" />
   </s:states>
   
   <s:Rect left = "0" right = "0" top = "0" 
      bottom = "0" radiusX = "5" radiusY = "5">
      <s:stroke>
         <s:LinearGradientStroke weight = "2" />
      </s:stroke>
      <s:fill>
         <s:LinearGradient rotation = "90">
            <s:entries>
               <s:GradientEntry color = "0xdddddd" />
               <s:GradientEntry color = "0x020202" alpha = ".5" />
            </s:entries>
         </s:LinearGradient>    
      </s:fill>
   </s:Rect>
   
   <s:Group id = "contentGroup" left = "0" right = "0" 
      top = "0" bottom = "0" minWidth = "0" minHeight = "0">
      <s:layout>
         <s:BasicLayout/>
      </s:layout>
   </s:Group>
</s:Skin>

Following is the content of the modified mxml file src/com.tutorialspoint/HelloWorld.mxml.

<?xml version = "1.0" encoding = "utf-8"?>
<s:Application xmlns:fx = "http://ns.adobe.com/mxml/2009"
   xmlns:s = "library://ns.adobe.com/flex/spark"
   xmlns:mx = "library://ns.adobe.com/flex/mx
   width = "100%" height = "100%" minWidth = "500" minHeight = "500">  
   
   <fx:Style source = "/com/tutorialspoint/client/Style.css" />
   <s:BorderContainer width = "630" height = "480" id = "mainContainer" 
      styleName = "container">
      <s:VGroup width = "100%" height = "100%" gap = "50" 
         horizontalAlign = "center" verticalAlign = "middle">
         <s:Label id = "lblHeader" text = "Layout Panels Demonstration" 
            fontSize = "40" color = "0x777777" styleName = "heading" />
         
         <s:Panel id = "skinnableContainerPanel" title = "Using SkinnableContainer" 
            width = "500" height = "300" >
            <s:layout>
               <s:VerticalLayout  gap = "10" verticalAlign = "middle" 
                  horizontalAlign = "center" />
            </s:layout>
            
            <s:SkinnableContainer 
               skinClass = "com.tutorialspoint.skin.SkinnableContainerSkin" 
               width = "50%" height = "50%" horizontalCenter = "0"
               verticalCenter = "0">
               
               <s:HGroup horizontalCenter = "0" verticalCenter = "0">
                  <s:BorderContainer width = "50" height = "50" 
                     borderWeight = "2" color = "0x323232" />
                  <s:BorderContainer width = "50" height = "50" 
                     borderWeight = "2" color = "0x323232" />
                  <s:BorderContainer width = "50" height = "50" 
                     borderWeight = "2" color = "0x323232" />
               </s:HGroup>
            </s:SkinnableContainer>
         </s:Panel>
      </s:VGroup>	 
   </s:BorderContainer>	
</s:Application>

Once you are ready with all the changes done, let us compile and run the application in normal mode as we did in Flex - Create Application chapter. If everything is fine with your application, it will produce the following result: [ Try it online ]

flex_layout_panels.htm