queue.js

/* Polyfill EventEmitter. */
var Queue = function () {
    this.events = {};
    this.queue = [];
    this.methodStr;
    this.current;
};

Queue.prototype.setMethod = function(methodStr){
	this.methodStr = methodStr;
}

Queue.prototype.add = function(t){
	var self = this;
	// prevent same object
	for(var i = 0 ; i < this.queue; i ++){
		if(t == this.queue[i]){
			return ;
		}
	}

	t['__'+this.methodStr] = t[this.methodStr];
	t[this.methodStr] = function(){
		var args = Array.prototype.slice.call(arguments);
		self.queue.push({obj : t, params : args});
		self.start();
	};
	
	t['__queueComplete'] = function(){
		if( self.current == t){
			self.current = undefined;
			self.start();
		}
	};
}

Queue.prototype.start = function(){
	var self = this;
	if(this.current){

	}else{
		var t = this.queue.shift();
		if(t){
			self.current = t.obj;
			t.obj['__'+this.methodStr].apply(t.obj,t.params);
		}
	}
}

Queue.prototype.on = function (event, listener) {
    if (typeof this.events[event] !== 'object') {
        this.events[event] = [];
    }
 
    this.events[event].push(listener);
};
 
Queue.prototype.off = function (event, listener) {
    var idx;
     if (typeof this.events[event] === 'object') {
        idx = indexOf(this.events[event], listener);
 
        if (idx > -1) {
            this.events[event].splice(idx, 1);
        }
    }
};
 
Queue.prototype.emit = function (event) {
    var i, listeners, length, args = [].slice.call(arguments, 1);
 
    if (typeof this.events[event] === 'object') {
        listeners = this.events[event].slice();
        length = listeners.length;
 
        for (i = 0; i < length; i++) {
            listeners[i].apply(this, args);
        }
    }
};
 
Queue.prototype.once = function (event, listener) {
    this.on(event, function g () {
        this.off(event, g);
        listener.apply(this, arguments);
    });
};