1 /* observable.js is part of Aloha Editor project http://aloha-editor.org
  2  *
  3  * Aloha Editor is a WYSIWYG HTML5 inline editing library and editor. 
  4  * Copyright (c) 2010-2012 Gentics Software GmbH, Vienna, Austria.
  5  * Contributors http://aloha-editor.org/contribution.php 
  6  * 
  7  * Aloha Editor is free software; you can redistribute it and/or
  8  * modify it under the terms of the GNU General Public License
  9  * as published by the Free Software Foundation; either version 2
 10  * of the License, or any later version.
 11  *
 12  * Aloha Editor is distributed in the hope that it will be useful,
 13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15  * GNU General Public License for more details.
 16  *
 17  * You should have received a copy of the GNU General Public License
 18  * along with this program; if not, write to the Free Software
 19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 20  * 
 21  * As an additional permission to the GNU GPL version 2, you may distribute
 22  * non-source (e.g., minimized or compacted) forms of the Aloha-Editor
 23  * source code without the copy of the GNU GPL normally required,
 24  * provided you include this license notice and a URL through which
 25  * recipients can access the Corresponding Source.
 26  */
 27 define(
 28 ['jquery'],
 29 function(jQuery, undefined) {
 30 	"use strict";
 31 	
 32 	var
 33 		$ = jQuery;
 34 
 35 	return {
 36 		_eventHandlers: null,
 37 
 38 		/**
 39 		 * Attach a handler to an event
 40 		 *
 41 		 * @param {String} eventType A string containing the event name to bind to
 42 		 * @param {Function} handler A function to execute each time the event is triggered
 43 		 * @param {Object} scope Optional. Set the scope in which handler is executed
 44 		 */
 45 		bind: function(eventType, handler, scope) {
 46 			this._eventHandlers = this._eventHandlers || {};
 47 			if (!this._eventHandlers[eventType]) {
 48 				this._eventHandlers[eventType] = [];
 49 			}
 50 			this._eventHandlers[eventType].push({
 51 				handler: handler,
 52 				scope: (scope ? scope : window)
 53 			});
 54 		},
 55 
 56 		/**
 57 		 * Remove a previously-attached event handler
 58 		 *
 59 		 * @param {String} eventType A string containing the event name to unbind
 60 		 * @param {Function} handler The function that is to be no longer executed. Optional. If not given, unregisters all functions for the given event.
 61 		 */
 62 		unbind: function(eventType, handler) {
 63 			this._eventHandlers = this._eventHandlers || {};
 64 			if (!this._eventHandlers[eventType]) {
 65 				return;
 66 			}
 67 			if (!handler) {
 68 				// No handler function given, unbind all event handlers for the eventType
 69 				this._eventHandlers[eventType] = [];
 70 			} else {
 71 				this._eventHandlers[eventType] = $.grep(this._eventHandlers[eventType], function(element) {
 72 					if (element.handler === handler) {
 73 						return false;
 74 					}
 75 					return true;
 76 				});
 77 			}
 78 		},
 79 
 80 		/**
 81 		 * Execute all handlers attached to the given event type.
 82 		 * All arguments except the eventType are directly passed to the callback function.
 83 		 *
 84 		 * @param (String} eventType A string containing the event name for which the event handlers should be invoked.
 85 		 */
 86 		trigger: function(eventType) {
 87 			this._eventHandlers = this._eventHandlers || {};
 88 			if (!this._eventHandlers[eventType]) {
 89 				return;
 90 			}
 91 
 92 			// preparedArguments contains all arguments except the first one.
 93 			var preparedArguments = [];
 94 			$.each(arguments, function(i, argument) {
 95 				if (i>0) {
 96 					preparedArguments.push(argument);
 97 				}
 98 			});
 99 
100 			$.each(this._eventHandlers[eventType], function(index, element) {
101 				element.handler.apply(element.scope, preparedArguments);
102 			});
103 		},
104 
105 		/**
106 		 * Clears all event handlers. Call this method when cleaning up.
107 		 */
108 		unbindAll: function() {
109 			this._eventHandlers = null;
110 		}
111 	};
112 });