center application NativeWindow on screen with semi-transparent background and content centered on screen

gistfile1.as

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication 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="800" height="600" 
					   backgroundAlpha="0.90" backgroundColor="#000000"
					   initialize="visible = false"
					   creationComplete="setupStage();" >
	<!-- -->
	<fx:Script>
		<![CDATA[
			// setup stage align and maximize window
			private function setupStage():void
			{
				if(stage)
				{
					stage.scaleMode = flash.display.StageScaleMode.NO_SCALE;
					stage.align = "";
				}
				this.nativeWindow.addEventListener(NativeWindowBoundsEvent.RESIZE, finishSetup);
				this.nativeWindow.maximize();
			};
			// when window is maximized show window on screen to avoid content flickering
			private function finishSetup(resizeEvent:NativeWindowBoundsEvent):void
			{
				this.nativeWindow.removeEventListener(NativeWindowBoundsEvent.RESIZE, finishSetup);
				this.visible = true;
			}
		]]>
	</fx:Script>
	<s:Panel width="800" height="600" horizontalCenter="0" verticalCenter="0">
		<s:controlBarContent/>
	</s:Panel>
</s:WindowedApplication>