Flex - Accordian Control

Introduction

The Accordian control is a navigator container which has a collection of child containers, but only one of them at a time is visible.

Class Declaration

Following is the declaration for mx.containers.Accordian class −

public class Accordion 
   extends Container
      implements IHistoryManagerClient, IFocusManagerComponent

Public Properties

Sr.No	Property & Description
1	headerRenderer : IFactory A factory used to create the navigation buttons for each child.
2	historyManagementEnabled : Boolean If set to true, this property enables history management within this Accordion container.
3	resizeToContent : Boolean If set to true, this Accordion automatically resizes to the size of its current child.
4	selectedChild : INavigatorContent A reference to the currently visible child container.
5	selectedIndex : int The zero-based index of the currently visible child container.

Protected Properties

Sr.No	Property & Description
1	contentHeight : Number [read-only] The height of the area, in pixels, in which content is displayed.
2	contentWidth : Number [read-only] The width of the area, in pixels, in which content is displayed.

Sr.No

Property & Description

contentHeight : Number

[read-only] The height of the area, in pixels, in which content is displayed.

contentWidth : Number

[read-only] The width of the area, in pixels, in which content is displayed.

Public Methods

Sr.No	Method & Description
1	Accordion() Constructor.
2	getHeaderAt(index:int):Button Returns a reference to the navigator button for a child container.
3	loadState(state:Object):void Loads the state of this object.
4	saveState():Object Saves the state of this object.

Events

Sr.No	Event & Description
1	change Dispatched when the selected child container changes.

Methods Inherited

This class inherits methods from the following classes −

mx.core.Container
mx.core.UIComponent
mx.core.FlexSprite
flash.display.Sprite
flash.display.DisplayObjectContainer
flash.display.InteractiveObject
flash.display.DisplayObject
flash.events.EventDispatcher
Object

Flex Accordian Control Example

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

Step	Description
1	Create a project with a name HelloWorld under a package com.tutorialspoint.client as explained in the Flex - Create Application chapter.
2	Modify HelloWorld.mxml as explained below. Keep rest of the files unchanged.
3	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/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 = "Complex Controls Demonstration" 
            fontSize = "40" color = "0x777777" styleName = "heading" />
            
         <s:Panel id = "accordianPanel" title = "Using Accordian" 
            width = "500" height = "300" >
            <s:layout>
               <s:HorizontalLayout  gap = "10" verticalAlign = "middle" 
                  horizontalAlign = "center" />	
            </s:layout>				
               
            <mx:Accordion id = "accordion" width = "95%" height = "90%">
               <s:NavigatorContent label = "Section 1" width = "100%" 
                  height = "100%">
                  <s:VGroup verticalAlign = "middle" horizontalAlign = "center" 
                     width = "100%" height = "100%">
                     <s:Label text = "Contents for Section 1" />	
                  </s:VGroup>							
               </s:NavigatorContent>
                  
               <s:NavigatorContent label = "Section 2" width = "100%" 
                  height = "100%">
                  <s:VGroup verticalAlign = "middle" horizontalAlign = "center"
                     width = "100%" height = "100%">
                     <s:Label text = "Contents for Section 2" />	
                  </s:VGroup>							
               </s:NavigatorContent>
                  
               <s:NavigatorContent label = "Section 3" width = "100%" 
                  height = "100%">
                  <s:VGroup verticalAlign = "middle" horizontalAlign = "center" 
                     width = "100%" height = "100%">
                     <s:Label text = "Contents for Section 3" />	
                  </s:VGroup>							
               </s:NavigatorContent>
                  
               <s:NavigatorContent label = "Section 4" width = "100%" 
                  height = "100%">
                  <s:VGroup verticalAlign = "middle" horizontalAlign = "center" 
                     width = "100%" height = "100%">
                     <s:Label text = "Contents for Section 4" />	
                  </s:VGroup>							
               </s:NavigatorContent>
            </mx:Accordion>
         </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_complex_controls.htm