AS3 Using Many Event Listeners Causing Problems, How to Reduce?

Question

Confusing title, my bad.

Basically, I have a list of names. Looping through, I add a MovieClip, Set 2 properties to it, the name, and an ID. The MovieClip is at the same time made to function as a button and I add 4 listeners, mouse up, over, down, or out. I do this with every name. The function each one is set to is the same.

EX: enemyButton[i].addEventListener(MouseEvent.MOUSE_UP, mouseUpHandler);

The enemyID turns up "not valid property," time to time when I click, it doesn't crash at all, but sometimes I have to hit the button a few times.

I have narrowed the problem down to having to be caused by the listeners.

The function as simple as:

EX: function mouseUpHandler(e:MouseEvent):void { enemySelected(e.target.enemyID); }

My question is, is too many listeners likely to be the problem? and how can I reduce them?

Here's a snippet of the loop:

var C:Class = Class(getDefinitionByName(enemies[i]));
var c:* = new C(); 
c.gotoAndStop(1);
enemyButton[i].enemyID = i;
c.name = "select" + i;
c.enemyID = i;
trace(c.enemyID);
enemyButton[i].addChild(c);
enemyScroll.addChild(enemyButton[i]);
enemyButton[i].enemyName.text = info[i][Const.NAME];
enemyButton[i].setChildIndex(enemyButton[i].getChildByName("enemyName"), enemyButton[i].numChildren-1);

Thanks.

Answer 1

If enemyButton is a MovieClip (created via attachMovie, maybe) and not strongly typed as a EnemyButton class, then the ID property becomes dynamic. In this situation, if your list of names contains incorrect data (missing ID field, maybe), then the ID property will remain undefined on some instances of the MovieClip.

You can check the list of data used to generate movie clips. You can run into the same error if you have blank lines in your data.

This has nothing to do with event listeners.

Answer 2

So you just want to generate a bunch of buttons with unique properties and know what button was clicked last. Generally it is very bad idea to implement button logic outside button object. Why? Because you work with object oriented language. Good news is that you work with as3 and it treats functions as objects, so you can assign function to var like this:

var callback:Function = function(name:String, enemyId:int){ /*do something*/ }

And.. you can pass function as a parameter to another function

function setCalback(func:Function){}

button.setCallback(callback);

So, what you really need is to create your own button class, add listeners inside it, add handlers(static handlers will reduce memory usage) and pass callback function to it, that will be called when user clicks button.

Answer 3

Don't mean to spam this much but this was easily fixed, though the responses might have been a better method.

I just had to change target to the currentTarget, that then allowed clicking anywhere on the "button" to work. Whereas before the target varied from childs added to it.

So, solved.

Thanks for the help.