How to resize stage in Adobe AIR to sit in Center when Full Screen?

Question

I've looked all over the web to try and figure out how to resize an Adobe Air apps viewport rectangle. And I can't seem to figure it out.

What I'm trying to do is make a game with Adobe AIR so that when the "backspace" key is pressed (for testing right now) it enables the game to go into FULL_SCREEN.

The game currently launches in stage.displayState.NORMAL, and I'm going to implement an option in the future to enable FULL_SCREEN.

However, the problem that I can't seem to figure out is how to get my stage to align in the center of the screen when FULL_SCREEN is active with Adobe AIR.

What I want is that when you go into FullScreen the stage is in the center like the first image posted.

<- This is the game when the adl launches with everything being centered.

<- And when the app goes into FULL_SCREEN, the stage aligns to the TOP_LEFT.

This is my Main.AS that handles the Stage Setup. How can I align the stage to be set in the middle when it goes into FullScreen. Like Binding of Issac?

[SWF(frameRate="60", width="1920", height="1080", backgroundColor="#000000")]
public class Main extends MovieClip {

    public var _starling:Starling;
    public static var screenWidth:Number = 0.0;
    public static var screenHeight:Number = 0.0;

    public function Main() {
        addEventListener(Event.ADDED_TO_STAGE, stageSetup); 
    }

    private function stageSetup(e:Event):void  {
        removeEventListener(Event.ADDED_TO_STAGE, stageSetup);

        stage.displayState = StageDisplayState.NORMAL;

        var rect:Rectangle = new Rectangle(0, 0, stage.fullScreenWidth, stage.fullScreenHeight);
        screenWidth = stage.fullScreenWidth  > 1920 ? 1920 : stage.fullScreenWidth;
        screenHeight = stage.fullScreenHeight > 1080 ? 1080  : stage.fullScreenHeight;

        Starling.handleLostContext = false;
        _starling = new Starling( GameEngine, stage);
        _starling.antiAliasing = 1;
        _starling.start();

        _starling.showStats = true; 
        stage.addEventListener(KeyboardEvent.KEY_DOWN, escKeyOverride); 
        stage.addEventListener(KeyboardEvent.KEY_DOWN, enableFullScreen);
        stage.addEventListener(Event.RESIZE, resize);   
    }
    private function enableFullScreen(e:KeyboardEvent):void {
        if (e.keyCode == 8) {
           stage.displayState = StageDisplayState.FULL_SCREEN_INTERACTIVE;
           stage.scaleMode = StageScaleMode.EXACT_FIT;
        } 
        else {
            //build in button listener for settings to resize back to normal
            stage.scaleMode = StageScaleMode.EXACT_FIT;
        }
    }
    private function escKeyOverride(e:KeyboardEvent):void  {
         if (e.keyCode == 27) {
            e.preventDefault();
        }
    }
    private function resize(e:Event):void {
        var viewPortRectangle:Rectangle = new Rectangle();
        viewPortRectangle.width     = stage.stageWidth;
        viewPortRectangle.height    = stage.stageHeight;
        Starling.current.viewPort   = viewPortRectangle;
        _starling.stage.stageWidth  = stage.stageWidth;
        _starling.stage.stageHeight = stage.stageHeight;
    }
}

Thanks.

Answer 1

When you set the fullscreen, you must set the stage.scaleMode to StageScaleMode.NO_SCALE, and set the stage.align to ""
In code:

stage.displayState = StageDisplayState.FULL_SCREEN_INTERACTIVE;
stage.scaleMode = StageScaleMode.NO_SCALE
stage.align = ""