1 /**
  2  * Copyright (C) 2013 KO GmbH <copyright@kogmbh.com>
  3  *
  4  * @licstart
  5  * This file is part of WebODF.
  6  *
  7  * WebODF is free software: you can redistribute it and/or modify it
  8  * under the terms of the GNU Affero General Public License (GNU AGPL)
  9  * as published by the Free Software Foundation, either version 3 of
 10  * the License, or (at your option) any later version.
 11  *
 12  * WebODF is distributed in the hope that it will be useful, but
 13  * WITHOUT ANY WARRANTY; without even the implied warranty of
 14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15  * GNU Affero General Public License for more details.
 16  *
 17  * You should have received a copy of the GNU Affero General Public License
 18  * along with WebODF.  If not, see <http://www.gnu.org/licenses/>.
 19  * @licend
 20  *
 21  * @source: http://www.webodf.org/
 22  * @source: https://github.com/kogmbh/WebODF/
 23  */
 24 
 25 /*global core, runtime*/
 26 
 27 /**
 28  * @constructor
 29  * @param {!Array.<!string>=} eventIds
 30  */
 31 core.EventNotifier = function EventNotifier(eventIds) {
 32     "use strict";
 33 
 34     var /**@type{!Object.<!string,!Array.<!Function>>}*/
 35         eventListener = {};
 36 
 37     /**
 38      * @param {!string} eventId
 39      * @param {*} args
 40      * @return {undefined}
 41      */
 42     this.emit = function (eventId, args) {
 43         var i, subscribers;
 44 
 45         runtime.assert(eventListener.hasOwnProperty(eventId),
 46             "unknown event fired \"" + eventId + "\"");
 47         subscribers = eventListener[eventId];
 48         // runtime.log("firing event \"" + eventId + "\" to " + subscribers.length + " subscribers.");
 49         for (i = 0; i < subscribers.length; i += 1) {
 50             subscribers[i](args);
 51         }
 52     };
 53 
 54     /**
 55      * @param {!string} eventId
 56      * @param {!Function} cb
 57      * @return {undefined}
 58      */
 59     this.subscribe = function (eventId, cb) {
 60         runtime.assert(eventListener.hasOwnProperty(eventId),
 61             "tried to subscribe to unknown event \"" + eventId + "\"");
 62         eventListener[eventId].push(cb);
 63     };
 64 
 65     /**
 66      * @param {!string} eventId
 67      * @param {!Function} cb
 68      * @return {undefined}
 69      */
 70     this.unsubscribe = function (eventId, cb) {
 71         var cbIndex;
 72         runtime.assert(eventListener.hasOwnProperty(eventId),
 73             "tried to unsubscribe from unknown event \"" + eventId + "\"");
 74 
 75         cbIndex = eventListener[eventId].indexOf(cb);
 76         runtime.assert(cbIndex !== -1, "tried to unsubscribe unknown callback from event \"" + eventId + "\"");
 77         if (cbIndex !== -1) {
 78             eventListener[eventId].splice(cbIndex, 1);
 79         }
 80     };
 81 
 82     /**
 83      * Register an event
 84      * @param {!string} eventId
 85      * @return {undefined}
 86      */
 87     function register(eventId) {
 88         runtime.assert(!eventListener.hasOwnProperty(eventId), "Duplicated event ids: \"" + eventId + "\" registered more than once.");
 89         eventListener[eventId] = [];
 90     }
 91     this.register = register;
 92 
 93     /**
 94      * @return {undefined}
 95      */
 96     function init() {
 97         if (eventIds) {
 98             eventIds.forEach(register);
 99         }
100     }
101 
102     init();
103 };
104