atom/vendor/ace/lib/event_emitter.js

/* vim:ts=4:sts=4:sw=4:
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Ajax.org Code Editor (ACE).
 *
 * The Initial Developer of the Original Code is
 * Ajax.org B.V.
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *      Fabian Jakobs <fabian AT ajax DOT org>
 *      Irakli Gozalishvili <rfobic@gmail.com> (http://jeditoolkit.com)
 *      Mike de Boer <mike AT ajax DOT org>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * under the terms of either the GPL or the LGPL, and not to allow others to
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 * decision by deleting the provisions above and replace them with the notice
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 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

define(function(require, exports, module) {
"use strict";

var EventEmitter = {};

EventEmitter._emit =
EventEmitter._dispatchEvent = function(eventName, e) {
    this._eventRegistry = this._eventRegistry || {};
    this._defaultHandlers = this._defaultHandlers || {};

    var listeners = this._eventRegistry[eventName] || [];
    var defaultHandler = this._defaultHandlers[eventName];
    if (!listeners.length && !defaultHandler)
        return;

    e = e || {};
    e.type = eventName;
    
    if (!e.stopPropagation) {
        e.stopPropagation = function() {
            this.propagationStopped = true;
        };
    }
    
    if (!e.preventDefault) {
        e.preventDefault = function() {
            this.defaultPrevented = true;
        };
    }

    for (var i=0; i<listeners.length; i++) {
        listeners[i](e);
        if (e.propagationStopped)
            break;
    }
    
    if (defaultHandler && !e.defaultPrevented)
        defaultHandler(e);
};

EventEmitter.setDefaultHandler = function(eventName, callback) {
    this._defaultHandlers = this._defaultHandlers || {};
    
    if (this._defaultHandlers[eventName])
        throw new Error("The default handler for '" + eventName + "' is already set");
        
    this._defaultHandlers[eventName] = callback;
};

EventEmitter.on =
EventEmitter.addEventListener = function(eventName, callback) {
    this._eventRegistry = this._eventRegistry || {};

    var listeners = this._eventRegistry[eventName];
    if (!listeners)
        var listeners = this._eventRegistry[eventName] = [];

    if (listeners.indexOf(callback) == -1)
        listeners.push(callback);
};

EventEmitter.removeListener =
EventEmitter.removeEventListener = function(eventName, callback) {
    this._eventRegistry = this._eventRegistry || {};

    var listeners = this._eventRegistry[eventName];
    if (!listeners)
        return;

    var index = listeners.indexOf(callback);
    if (index !== -1)
        listeners.splice(index, 1);
};

EventEmitter.removeAllListeners = function(eventName) {
    if (this._eventRegistry) this._eventRegistry[eventName] = [];
};

exports.EventEmitter = EventEmitter;

});