gistfile1.js

var EventGroup = function(target){
	this.target = target || window;
	this.handler = {};
	this.doPreventDefault = true;
	this.doStopPropagation = true;
	var self = this;
	this.delegate = function(e){
		if(e){
			if(self.doStopPropagation) e.stopPropagation();
			if(self.doPreventDefault) e.preventDefault();
		}else{
			e = window.event;
			if(self.doStopPropagation) e.cancelBubble = true;
			if(self.doPreventDefault) e.returnValue = false;
			e.target = e.srcElement;
		}
		self.handler[e.type].call(self, e);
	}
	return this;
}
EventGroup.prototype.listen = function(type,func){
	var target = this.target;
	this.handler[type] = func;
	if(target.addEventListener){
		target.addEventListener(type,this.delegate,false);
	}else if(target.attachEvent){
		target.attachEvent('on'+type,this.delegate);
	}else{
		target['on'+type] = this.delegate;
	}
	return this;
};
EventGroup.prototype.unlisten = function(type){
	var target = this.target;
	if(target.removeEventListener){
		target.removeEventListener(type,this.delegate,false);
	}else if(target.detachEvent){
		target.detachEvent('on'+type,this.delegate);
	}else{
		target['on'+type] = null;
	}
	this.handler[type] = null;
	return this;
};
EventGroup.prototype.destroy = function(type){
	for (var type in this.handler) if(this.handler.hasOwnProperty(type)) {
		this.unlisten(type);
	}
};