Flex TabNavigator Image Snapshot Icons

Example files below illustrate generating thumbnail snapshots of tabs in a Flex TabNavigator. The thumbnails are shows as tab icons.
See this flexcoders thread.

ImgSnapshot.mxml - Main Application File:

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" creationComplete="init()">

<mx:Script>
<![CDATA[
import mx.events.IndexChangedEvent;
import mx.containers.TabNavigator;

private var tabNav:TabNavigator = new TabNavigator();

private function init():void
{
  // tab1
  var tabChild1:MyComponent = new MyComponent(0);
  this.tabNav.addChild(tabChild1);

  // tab2
  var tabChild2:MyComponent = new MyComponent(1);
  this.tabNav.addChild(tabChild2);

  this.tabNav.percentHeight = 100;
  this.tabNav.percentWidth = 100;
  this.addChild(this.tabNav);
}     
]]>
</mx:Script>

</mx:Application>

MyComponent Class - MyComponent.as:

package
{
  import flash.events.Event;
 
  import mx.charts.PieChart;
  import mx.charts.series.PieSeries;
  import mx.collections.ArrayCollection;
  import mx.containers.HBox;
  import mx.containers.TabNavigator;
  import mx.core.Container;
  import mx.events.FlexEvent;
 
  public class MyComponent extends Container
  {
 private var box:HBox = new HBox();
 private var chart:PieChart = new PieChart();
 private var index:int;
 
 public function MyComponent(indx:int)
 {
     super();
   
     this.index = indx;
     this.label = "Tab " + this.index;
     this.percentHeight = 100;
     this.percentWidth = 100;
  
     this.addEventListener(FlexEvent.UPDATE_COMPLETE, updateComplete);
 }
  
 override protected function createChildren():void
 {
     super.createChildren();        
     this.box.addChild(this.getPie());   
     this.addChild(this.box);
 }
  
 override protected function updateDisplayList(
   unscaledWidth:Number, unscaledHeight:Number):void
 {
     super.updateDisplayList(unscaledWidth, unscaledHeight);
     this.box.setActualSize(unscaledWidth, unscaledHeight);
     this.chart.setActualSize(unscaledWidth, unscaledHeight);
 }
  
 private function updateComplete(event:Event):void
 {
     var tabNav:TabNavigator = TabNavigator(this.parent);
     if (this.width == 0 && this.height == 0) {
  var selTab:MyComponent = MyComponent(tabNav.getChildAt(tabNav.selectedIndex));    
    
         this.width = selTab.width;
         this.height = selTab.height;
         this.updateDisplayList(selTab.width, selTab.height);
        
         return;
     }         
     if (this.icon == null)
         this.icon = IconUtil.getIconClass(this, tabNav.getTabAt(this.index), 150, 100); 
      }
  
 private function getPie():PieChart
 {   
     chart.percentWidth = 100;
     chart.percentHeight = 100;
     chart.showDataTips = true;
     chart.dataProvider = this.getChartDataProvider();

     var series:PieSeries = new PieSeries();             
     series.nameField = "label";
     series.field = "data";
     series.filters = [];
     chart.series = [series];
   
     return chart;
 }
  
 private function getChartDataProvider():ArrayCollection
 {
     var arr:Array = [];
           arr.push({label:"East", data:24});
           arr.push({label:"West", data:32});
           arr.push({label:"North", data:22});
           arr.push({label:"South", data:11});
           arr.push({label:"Texas", data:5});  
           return new ArrayCollection(arr);
 }
  }
}

IconUtil.as:

package
{
import flash.display.BitmapData;
import flash.events.Event;
import flash.geom.Matrix;
import flash.utils.Dictionary;

import mx.core.BitmapAsset;
import mx.core.UIComponent;
import mx.graphics.ImageSnapshot;

public class IconUtil extends BitmapAsset
{
    private static var dictionary:Dictionary = new Dictionary(true);

    public function IconUtil()
    {
        addEventListener(Event.ADDED, addedHandler, false, 0, true);            
    }

    private function addedHandler(event:Event):void
    {
        if (this.parent == null)
            return;
    
        var value:Object = dictionary[this.parent];
        if (value == null)
            return;
        
        this.bitmapData = value.src;
        UIComponent(this.parent).invalidateSize();
    }

    public static function getIconClass(source:UIComponent, target:UIComponent,
            width:int, height:int):Class
    {         
        if (source.width <= 0 || source.height <= 0)
            return null;
       
        var scaleWidth:Number = width/source.width;          
        var scaleHeight:Number = height/source.height;          
        var mtrx:Matrix = new Matrix(scaleWidth, 0, 0, scaleHeight);          
        var bitmap:BitmapData = ImageSnapshot.captureBitmapData(source, mtrx);
        dictionary[target] = {src:bitmap, w:width, h:height};             

        return IconUtil;                      
    }           
 } 
}