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The workflow consists of:

• A Command to launch the popup (via the Flex PopupManager)
• A Mediator that handles events coming from the popup view component

The popup view component’s Mediator also handles closing of the popup and removes itself from the RobotLegs mediatorMap when it’s no longer required.

Note: I should point out that the source for the SWF below includes only some of the RobotLegs framework source-code. To run the source-code, please download the current version of RobotLegs.

Here’s the SWF and sample code. Feel free to use and abuse, no warranties given or implied. View source

View source

The following code will result in an image with zero width/height, so the image won’t show:

var img:Image = new Image();
img.source = "myfile.jpg";

Solutions:

1. Assign specific values for width and height:

   img.width = 100;
   img.height = 100;

2. Set the ‘scaleContent’ property to false – the image will then resize its container automatically, once it has loaded. Note that this technique has no effect if loading image from non-trusted domains!

   img.scaleContent = false;
    
   // or, if loading cross-domain, provided a crossdomain policy file allows access
   img.trustContent = true;
   img.scaleContent = false;

3. Use an event listener to detect when the image has finished loading, then assign the correct width and height. Again, this will only work if the image has been loaded from a trusted domain.

   img.addEventListener(Event.COMPLETE, onImageComplete);
    
   protected function onImageComplete(evt:Event):void
   {
       var img:Image = evt.target as Image;
       img.removeEventListener(Event.COMPLETE, onImageComplete);
       img.width = img.content.width;
       img.height = img.content.height;
   }

I’ve mainly blogged about it so I remember the next time I write some code – but maybe it will also help somebody else debug their missing image problems.

The custom preloader class extends Sprite and implements the IPreloaderDisplay class. Once the Sprite’s ‘root’ property becomes available, you can use the standard AS3 way of accessing flashvars, namely:

var flashvars:Object = root.loaderInfo.parameters;

This code should be used once the ‘root’ property has been initialised – for example in the ‘initialize()’ method defined by the IPreloaderDisplay interface:

public function initialize():void
{
     var flashvars:Object = root.loaderInfo.parameters;
}

Just for reference, compare the above approach with the standard Flex method of accessing flashvar parameters – which becomes possible once the main Application instance has been created:

var flashvars:Object = Application.application.parameters