reventtarget.js

/*
 * ***** BEGIN LICENSE BLOCK *****
 * Copyright (c) 2011-2012 VMware, Inc.
 *
 * For the license see COPYING.
 * ***** END LICENSE BLOCK *****
 */

/* Simplified implementation of DOM2 EventTarget.
 *   http://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-EventTarget
 */
var REventTarget = function() {};
REventTarget.prototype.addEventListener = function (eventType, listener) {
    if(!this._listeners) {
         this._listeners = {};
    }
    if(!(eventType in this._listeners)) {
        this._listeners[eventType] = [];
    }
    var arr = this._listeners[eventType];
    if(utils.arrIndexOf(arr, listener) === -1) {
        arr.push(listener);
    }
    return;
};

REventTarget.prototype.removeEventListener = function (eventType, listener) {
    if(!(this._listeners && (eventType in this._listeners))) {
        return;
    }
    var arr = this._listeners[eventType];
    var idx = utils.arrIndexOf(arr, listener);
    if (idx !== -1) {
        if(arr.length > 1) {
            this._listeners[eventType] = arr.slice(0, idx).concat( arr.slice(idx+1) );
        } else {
            delete this._listeners[eventType];
        }
        return;
    }
    return;
};

REventTarget.prototype.dispatchEvent = function (event) {
    var t = event.type;
    var args = Array.prototype.slice.call(arguments, 0);
    if (this['on'+t]) {
        this['on'+t].apply(this, args);
    }
    if (this._listeners && t in this._listeners) {
        for(var i=0; i < this._listeners[t].length; i++) {
            this._listeners[t][i].apply(this, args);
        }
    }
};