Thanks for the comment.

Yes, that solution does work fine (it’s in Adobe’s bug report), providing you do not remove the item from the Display List then add it again – because then there’s no init handler.

I’ve had a further look at the issue and put together a few files for testing. I called your fix “Fix 1″ and the other one “Fix 2″. See what you think:

[download id="1" format="1"]

Your fix can be made to work fully by us adding the init handler again on removal, and that’s what I’ve done in the files. So it looks like this:

public function SquareInner()
{
  addEventListener(Event.ADDED_TO_STAGE, init,
  false, 0, true);
  addEventListener(Event.REMOVED_FROM_STAGE, onRemove,
  false, 0, true);
}

/***************************************************
Instance methods
***************************************************/

private function init(e:Event):void
{
  // remove handler so it only fires once:
  removeEventListener(Event.ADDED_TO_STAGE, init, false);
  trace(e.target + " was added to the stage");
}

private function onRemove(e:Event):void
{
  trace(this + " was removed from stage - adding init
  handler again");
  addEventListener(Event.ADDED_TO_STAGE, init, false,
  0, true);
}

This method might actually be neater than Fix 2 (it is less verbose).

We have to be so careful not to leave stray event handlers in AS3 because they can lead to memory leaks. Both of these methods leave the ADDED_TO_STAGE handler in the object while it is off the Display List, but this should not be a problem for GC as it it not repeatedly firing and doesn’t depend on the stage.

This is quite a fiddly issue. But inside the “Fix 1″ folder, there’s another folder called “With Inheritance”. Here I think I have really cracked it, by taking care of business in a superclass. You then override its methods with further code. Let me know what you think about it all anyway and if you spot any problems with this approach.

public function init(e:Event):void
{
  // remove the listener so init will only
  // be called once....
  removeEventListener(Event.ADDED_TO_STAGE, init);

  // code dependent on stage property
  y = stage.stageHeight-100;
}