/*
* extend
* Visit http://createjs.com/ for documentation, updates and examples.
*
* Copyright (c) 2010 gskinner.com, inc.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/

/**
 * @module CreateJS
 */

// namespace:
this.createjs = this.createjs||{};

/**
 * @class Utility Methods
 */

/**
 * Sets up the prototype chain and constructor property for a new class.
 *
 * This should be called right after creating the class constructor.
 *
 * 	function MySubClass() {}
 * 	createjs.extend(MySubClass, MySuperClass);
 * 	MySubClass.prototype.doSomething = function() { }
 *
 * 	var foo = new MySubClass();
 * 	console.log(foo instanceof MySuperClass); // true
 * 	console.log(foo.prototype.constructor === MySubClass); // true
 *
 * @method extend
 * @param {Function} subclass The subclass.
 * @param {Function} superclass The superclass to extend.
 * @return {Function} Returns the subclass's new prototype.
 */
createjs.extend = function(subclass, superclass) {
	"use strict";

	function o() { this.constructor = subclass; }
	o.prototype = superclass.prototype;
	return (subclass.prototype = new o());
};