erikdebruin/sdk.asjs/mustella/tests/mobile/utils/MultiDPIBitmapSource/swfs/comps/InstrumentedBitmapImage.as

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//  this work for additional information regarding copyright ownership.
//  The ASF licenses this file to You under the Apache License, Version 2.0
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//      http://www.apache.org/licenses/LICENSE-2.0
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package comps
{
	import flash.events.Event;
	
	import mx.events.FlexEvent;
	
	import spark.components.IItemRenderer;
	import spark.components.IconItemRenderer;
	import spark.primitives.BitmapImage;
	
	/**
	 * A very simple subclass of BitmapImage that fires an event when the
	 * icon is finished loading, whether that image is being loaded in or
	 * coming from a cache.
	 * 
	 * Designed for use in Mustella in a subclass of IconItemRenderer.  Set 
	 * the iconDisplayClass property in your renderers constructor to enable
	 * this functionality.
	 * 
	 * This fires an event of the form "itemRenderer0IconReady" against the
	 * owner of the item renderer.
	 */
	public class InstrumentedBitmapImage extends BitmapImage
	{
		public function InstrumentedBitmapImage()
		{
			super();
			// listen for when the image is changing
			addEventListener(FlexEvent.READY, fireIconReady);
		}
		
		/**
		 * Fire an event against the owner of the renderer
		 */
		private function fireIconReady(e:Event):void 
		{
			var parentItemRenderer:IconItemRenderer = parent as IconItemRenderer;
			var itemIndex:Number = parentItemRenderer.itemIndex;

			var iconReadyEventString:String = "itemRenderer" + itemIndex;
            
            if (source != parentItemRenderer.iconPlaceholder)
                iconReadyEventString += "IconReady";
            else
                iconReadyEventString += "IconPlaceholderReady";
            
			trace(iconReadyEventString);
			parentItemRenderer.owner.dispatchEvent(new Event(iconReadyEventString));
            
		}
	}
}