Move documentation

documentation/frontend/js/libs/EventDispatcher.js

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+/**
+ * @author mrdoob / http://mrdoob.com/
+ */
+
+var EventDispatcher = function () {};
+
+Object.assign( EventDispatcher.prototype, {
+
+	addEventListener: function ( type, listener ) {
+
+		if ( this._listeners === undefined ) this._listeners = {};
+
+		var listeners = this._listeners;
+
+		if ( listeners[ type ] === undefined ) {
+
+			listeners[ type ] = [];
+
+		}
+
+		if ( listeners[ type ].indexOf( listener ) === - 1 ) {
+
+			listeners[ type ].push( listener );
+
+		}
+
+	},
+
+	hasEventListener: function ( type, listener ) {
+
+		if ( this._listeners === undefined ) return false;
+
+		var listeners = this._listeners;
+
+		if ( listeners[ type ] !== undefined && listeners[ type ].indexOf( listener ) !== - 1 ) {
+
+			return true;
+
+		}
+
+		return false;
+
+	},
+
+	removeEventListener: function ( type, listener ) {
+
+		if ( this._listeners === undefined ) return;
+
+		var listeners = this._listeners;
+		var listenerArray = listeners[ type ];
+
+		if ( listenerArray !== undefined ) {
+
+			var index = listenerArray.indexOf( listener );
+
+			if ( index !== - 1 ) {
+
+				listenerArray.splice( index, 1 );
+
+			}
+
+		}
+
+	},
+
+	dispatchEvent: function ( event ) {
+
+		if ( this._listeners === undefined ) return;
+
+		var listeners = this._listeners;
+		var listenerArray = listeners[ event.type ];
+
+		if ( listenerArray !== undefined ) {
+
+			event.target = this;
+
+			var array = [], i = 0;
+			var length = listenerArray.length;
+
+			for ( i = 0; i < length; i ++ ) {
+
+				array[ i ] = listenerArray[ i ];
+
+			}
+
+			for ( i = 0; i < length; i ++ ) {
+
+				array[ i ].call( this, event );
+
+			}
+
+		}
+
+	}
+
+} );