CODEWITHSUNDEEP
actionscript-3
Fabricio
Fabricio

Reputation: 7935

An approach to remove a listener when it is dispatched

I find addEventListener method a bit limited. I would like to use another version of it, made by me. I would like to insert a parameter that will tell if a dispatched event can be auto removed, so it will avoid me have to write this in everywhere:

obj.addEventListener(Click, function onClick(e:Event):void {
    obj.removeEventListener(Click, onClick); // <--- I want to avoid this
});

Then:

obj.addEventListener(Click, function onClick(e:Event):void {
    // no need anymore.
}, true); // <--- see

What approach can I take in order to reach that?

Upvotes: 0

Views: 94

Answers (2)

Glitcher
Glitcher

Reputation: 1184

A quick and fairly simple solution to allow for anonymous functions is the arguments.callee property

obj.addEventListener(Event.WHATEVER, function(e:Event)
{
    e.currentTarget.removeEventListener(Event.WHATEVER, arguments.callee);
    //Do your stuff
}

This creates the event listener and listen function at the same time, in the remove listener, it uses arguments.callee the reference the called function, allowing it to remove itself.

Upvotes: 0

ZuzEL
ZuzEL

Reputation: 13675

You can always intercept your addEventListener method call using override with closures: 

    override public function addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void 
    {
        var self = this;
        var weakListener:Function = function(e) {
            self.removeEventListener(type, weakListener);
            listener(e);
        }
        super.addEventListener(type, weakListener, useCapture, priority, useWeakReference);
    }

Upvotes: 1

Related Questions