package {

import flash.display.*;

import flash.events.*;

 

import mx.events.FlexEvent;

import mx.preloaders.DownloadProgressBar;

import mx.preloaders.IPreloaderDisplay;

 

public class Preloader extends DownloadProgressBar implements IPreloaderDisplay {

 

    [Embed(source="gui/progressBar/progressBarSources/background.png")]

    private var _backGround:Class;

 

    [Embed(source="gui/progressBar/progressBarSources/frontground.png")]

    private var _frontGround:Class;

 

    private var _imgBackGround:Bitmap = new _backGround;

    private var _imgFrontGround:Bitmap = new _frontGround;

 

    public function Preloader() {

        super();

    }

 

    override public function set preloader(preloader:Sprite):void {

        preloader.addEventListener(ProgressEvent.PROGRESS, handleProgress);

        preloader.addEventListener(Event.COMPLETE, handleComplete);

        preloader.addEventListener(FlexEvent.INIT_PROGRESS, handleInitProgress);

        preloader.addEventListener(FlexEvent.INIT_COMPLETE, handleInitComplete);

    }

 

    override public function initialize():void {

        this.addChild(_imgBackGround);

        this.addChild(_imgFrontGround);

        this.x = this.stage.stageWidth / 2 - _imgBackGround.width / 2;

        this.y = this.stage.stageHeight / 2 - _imgFrontGround.height / 2;

    }

 

    private function loaderCompleteHandler(event:Event):void {

        //

    }

 

    private function handleProgress(event:ProgressEvent):void {

        var percentage:Number = event.bytesLoaded / event.bytesTotal;

 

        if (percentage <= 1) {

            _imgFrontGround.scaleX = 1 - percentage;

            _imgFrontGround.x = uint(_imgBackGround.width * percentage) + 1;

        }

        if (percentage > 1)

            _imgFrontGround.visible = false;

    }

 

    private function handleComplete(event:Event):void {

    }

 

    private function handleInitProgress(event:Event):void {

    }

 

    private function handleInitComplete(event:Event):void {

        dispatchEvent(new Event(Event.COMPLETE));

    }

 

    private function handleIOError(event:IOErrorEvent):void {

    }

}

}

<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"

               xmlns:s="library://ns.adobe.com/flex/spark"

               xmlns:gui="gui.styles.*"

               width="760" height="730"

               backgroundColor="#001144"

               preloader="Preloader"

               addedToStage="creationCompleteHandler()">

private function handleProgress(event:ProgressEvent):void {

        var percentage:Number = event.bytesLoaded / event.bytesTotal;

 

        trace(percentage);

 

        if (percentage <= 1) {

            _imgFrontGround.scaleX = 1 - percentage;

            _imgFrontGround.x = uint(_imgBackGround.width * percentage) + 1;

        }

        if (percentage > 1)

            _imgFrontGround.visible = false;

    }