File: src/pixi/utils/EventTarget.js
    
/**
 * https://github.com/mrdoob/eventtarget.js/
 * THankS mr DOob!
 */
PIXI.EventTarget = function () {
	var listeners = {};
	
	this.addEventListener = this.on = function ( type, listener ) {
		
		
		if ( listeners[ type ] === undefined ) {
			listeners[ type ] = [];
			
		}
		if ( listeners[ type ].indexOf( listener ) === - 1 ) {
			listeners[ type ].push( listener );
		}
	};
	this.dispatchEvent = this.emit = function ( event ) {
		
		for ( var listener in listeners[ event.type ] ) {
			listeners[ event.type ][ listener ]( event );
			
		}
	};
	this.removeEventListener = this.off = function ( type, listener ) {
		var index = listeners[ type ].indexOf( listener );
		if ( index !== - 1 ) {
			listeners[ type ].splice( index, 1 );
		}
	};
};