AS3 How to detect startTouchDrag on Stage with no target?

Question

I'm really new to using Action Script in general and could use a good explanation on how to do this as well as how it works.

I'm trying to create a stage event in AS3 for Android.

When the user touches the stage and not an object in particular I need to detect if they are dragging and the location of where there finger has dragged to.

I've started like this to detect if they have touched the stage:

stage.addEventListener(TouchEvent.TOUCH_BEGIN, stageTouchBegin); 

var stageTouchDragBounds:Rectangle = new Rectangle(0, 0, stage.stageWidth, stage.stageHeight);

function stageTouchBegin(event:TouchEvent):void
{
event.target.startTouchDrag(event.touchPointID, false, stageTouchDragBounds:Rectangle);
trace(event.stageX);
trace(event.stageY);
}

This line is where I get the error and I'm assuming that it's because target would typically be referencing a movie symbol or something but in this case it's not because its the stage. I tried replacing target with stage but it didn't work:

event.target.startTouchDrag(event.touchPointID, false, stageTouchDragBounds:Rectangle);

Here is the error: 1061: Call to a possibly undefined method startTouchDrag through a reference with static type flash.events:TouchEvent.

---

From there my plan was to proceed to use something like this to start recording where they were at:

var curPosX; var curPosY;

function stageTouchMoveHandler(event:TouchEvent):void
{   
trace(event.stageX);
this.curPosX = event.stageX;
trace(event.stageY);
this.curPosY = event.stageY;
}

Then handle the ending as such:

function stageTouchEndHandler(event:TouchEvent):void
{
event.target.stopTouchDrag(event.touchPointID);
}

Any insight/advice on how to do this or an explanation of target, especially example code, would be greatly appreciated. Thank you for your time!

Answer 1

After thinking about what you are trying to do, I think the answer to your question is don't call the startTouchDrag() method and proceed w/your plans. What you have shown is the right approach to determine where the user started/stopped their "touch move" gesture.

It makes no sense to try and drag the stage ... the stage is literally a stage that your Flash movie is shown on. It contains the entire Flash application, and as such cannot be dragged.

To reiterate what I stated in my comment above, startTouchDrag() is a method you call on a Sprite (or some object that extends Sprite). This method is meant to be used when you want to drag something across the screen, like in a drag and drop operation.