Load and play embedded SWF file in Flex / Actionscript

Question

I'm trying to create / use a pre-loader in my flex application. The preloader is a SWF file which has 100 frames (1 for every percent of the loader progress). Basically I am trying to Embed this SWF file in my application, display it on screen and change the frame number being displayed as the progress completes.

The code I have so far is (which extends Canvas):

[Embed("/../assets/preLoader.swf")]
private var SWFClass:Class;

private var _preLoader:MovieClip;

private var _progress:Number;

public function set progress(value:Number) : void {
    _progress = value;

    if(progress < 100) {
        _preLoader.gotoAndPlay(progress, null);
    }else {
        _preLoader.gotoAndStop(0, null);
    }
}   

[Bindable]
public function get progress() : Number {
    return _progress;
}



(Called on creationComplete event)          
private function init() : void {
    _preLoader = MovieClip(new SWFClass());

    this.addChild(_preLoader);

    _preLoader.play();
}

The error I am getting is:

TypeError: Error #1034: Type Coercion failed: cannot convert widgets::PreLoader_SWFClass@30b3be51 to mx.core.IUIComponent.at mx.core::Container/http://www.adobe.com/2006/flex/mx/internal::addingChild()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\Container.as:3259]

Please help!

Answer 1

You need to have a wrapper over MovieClip that implements the IUIComponent in order to be able to pass to addChild(). From the addChild() documentation:

Note: While the child argument to the method is specified as of type DisplayObject, the argument must implement the IUIComponent interface to be added as a child of a container. All Flex components implement this interface.

You will need something like this:

public class MovieClipUIComponent extends UIComponent {
   public function MovieClipUIComponent (mc:MovieClip) {
      super ();

      mcHeight = mc.height;
      mcWidth = mc.width;

      // add your own magic

      addChild (mc);
   }
}

Warning: Untested code, should give you an idea only!