Flash Game ArgumentError: Error #2025 removeChild - actionscript-3

Question

I'm trying to get the bat character to remove the jack/2/3 child(s) in my game here, but I keep getting the ArgumentError: Error #2025. I understand that I may be removing a child twice, perhaps? I'm looking around and I'm not really experienced in this stuff so I'm having a hard time understanding what needs to be done to fix this issue. Can someone tell me what needs to be done with my code specifically, please?
var jack:pumpkin = new pumpkin();
var jack2:pumpkin = new pumpkin();
var jack3:pumpkin = new pumpkin();
var score:Number = 0;
scoreBox.text = String(score);
addChild(jack);
jack.x = 125;
jack.y = 285;
addChild(jack2);
jack2.x = 270;
jack2.y = 310;
addChild(jack3);
jack3.x = 445;
jack3.y = 285;
stage.addEventListener(KeyboardEvent.KEY_DOWN, moveLeft);
stage.addEventListener(KeyboardEvent.KEY_DOWN, moveRight);
stage.addEventListener(KeyboardEvent.KEY_DOWN, moveDown);
stage.addEventListener(KeyboardEvent.KEY_DOWN, moveUp);
stage.addEventListener(KeyboardEvent.KEY_UP, bump);
function moveLeft(e:KeyboardEvent):void {
if (e.keyCode == 37) {
bat.x -= 5;
}
}
function moveRight(e:KeyboardEvent):void {
if (e.keyCode == 39) {
bat.x += 5;
}
}
function moveDown(e:KeyboardEvent):void {
if (e.keyCode == 40) {
bat.y += 5;
}
}
function moveUp(e:KeyboardEvent):void {
if (e.keyCode == 38) {
bat.y -= 5;
}
}
function bump(e:KeyboardEvent):void {
stage.addEventListener(Event.ENTER_FRAME, bumpIt);
function bumpIt(e:Event):void {
if (bat.hitTestObject(jack)) {
stage.removeEventListener(Event.ENTER_FRAME, bumpIt);
removeChild(jack);
score++;
scoreBox.text = String(score);
}
if (bat.hitTestObject(jack2)) {
stage.removeEventListener(Event.ENTER_FRAME, bumpIt);
removeChild(jack2);
score++;
scoreBox.text = String(score);
}
if (bat.hitTestObject(jack3)) {
stage.removeEventListener(Event.ENTER_FRAME, bumpIt);
removeChild(jack3);
score++;
scoreBox.text = String(score);
}
}
}

Answer 1

Due to the nested bumpit() event handler, on every key up you're adding another enter frame event if your hit-test has no collision.
On KeyboardEvent.KEY_UP, event handler calls bump() which adds an Event.ENTER_FRAME listener that will call bumpIt().
If bat.hitTestObject() is true, you remove Event.ENTER_FRAME.
If not, you still have the Event.ENTER_FRAME listener firing bumpIt() every frame.
So, every key up you're potentially adding another frame handler.
If ten key up events occurred and none of them hit test your objects, you are now calling bumpIt ten times a frame.
If you need to hit test on key up, just put the logic there:
stage.addEventListener(KeyboardEvent.KEY_UP, bump);
function bump(e:KeyboardEvent):void {
if (bat.hitTestObject(jack)) { /* ... */ }
}
Or, if you're tracking an animation sequence after key up, maybe add some state variable, such as:
var isFlying:Boolean = false;
stage.addEventListener(KeyboardEvent.KEY_UP, bump);
function bump(e:KeyboardEvent):void {
// If bat is already flying, don't add another frame handler
if (isFlying)
return;
// Otherwise, indicate bat is now flying and add frame handler
isFlying = true;
stage.addEventListener(Event.ENTER_FRAME, bumpIt);
}
Then, if your hit-test works and you remove your frame handler, reset the state variable:
stage.removeEventListener(Event.ENTER_FRAME, bumpIt);
isFlying = false;
Another solution is to remove the nested handlers. Because you have nested bumpIt() inside bump(), you are seeing cumulative firing of callbacks due to scope:
function bump():void {
function bumpIt():void { /* ... */ }
}
Simply promote bumpIt():
function bump():void { /* ... */ }
function bumpIt():void { /* ... */ }