/**
 * domready.js
 *
 * Cross browser mozilla's 'onDOMContentLoaded' implementation.
 * Executes a function when the dom tree is loaded without waiting for images.
 *
 * Based on +Element.Events.domready+ from Mootools open source project,
 * this tiny javascript library adds the emulated 'DOMContentLoaded' functionality.
 *
 * Features:
 * - No dependency on external libraries
 * - Compatible with Prototype.js
 *
 * Tested browsers (Windows):
 * - IE 7 (XP standalone)
 * - IE 6 SP2
 * - Firefox 2.0.0.4
 * - Opera 9.21
 *
 * Tested browsers (Mac OS X):
 * - Safari 2.0.4
 * - Firefox 2.0.0.4
 * - Mac Opera 9.21
 * - Mac IE 5.2.3
 *
 * Copyright (c) 2007 Takanori Ishikawa.
 * License: MIT-style license.
 *
 * MooTools Copyright:
 * copyright (c) 2007 Valerio Proietti, <http://mad4milk.net>
 *
 *
 * See Also:
 *
 * mootools
 * http://mootools.net/
 *
 * The window.onload Problem - Solved!
 * http://dean.edwards.name/weblog/2005/09/busted/
 *
 * [PATCH] Faster onload for Event.onload
 * http://dev.rubyonrails.org/ticket/5414
 * Changeset 6596: Support for "DOMContentLoaded" event handling (prototype.js event branch)
 * http://dev.rubyonrails.org/changeset/6596
 *
 */
 
if (typeof Event == 'undefined') Event = new Object();
 
/*
 * Registers function +fn+ will be executed when the dom
 * tree is loaded without waiting for images.
 *
 * Example:
 *
 * Event.domReady.add(function() {
 * ...
 * });
 *
 */
Event.domReady = {
    add: function(fn) {
     
        //-----------------------------------------------------------
        // Already loaded?
        //-----------------------------------------------------------
        if (Event.domReady.loaded) return fn();
         
        //-----------------------------------------------------------
        // Observers
        //-----------------------------------------------------------
        var observers = Event.domReady.observers;
        if (!observers) observers = Event.domReady.observers = [];
        // Array#push is not supported by Mac IE 5
        observers[observers.length] = fn;
         
        //-----------------------------------------------------------
        // domReady function
        //-----------------------------------------------------------
        if (Event.domReady.callback) return;
        Event.domReady.callback = function() {
            if (Event.domReady.loaded) return;
             
            Event.domReady.loaded = true;
            if (Event.domReady.timer) {
                clearInterval(Event.domReady.timer);
                Event.domReady.timer = null;
            }
             
            var observers = Event.domReady.observers;
            for (var i = 0, length = observers.length; i < length; i++) {
                var fn = observers[i];
                observers[i] = null;
                fn(); // make 'this' as window
            }
            Event.domReady.callback = Event.domReady.observers = null;
        };
         
        //-----------------------------------------------------------
        // Emulates 'onDOMContentLoaded'
        //-----------------------------------------------------------
        var ie = !!(window.attachEvent && !window.opera);
        var webkit = navigator.userAgent.indexOf('AppleWebKit/') > -1;
         
        if (document.readyState && webkit) {
         
        // Apple WebKit (Safari, OmniWeb, ...)
        Event.domReady.timer = setInterval(function() {
            var state = document.readyState;
            if (state == 'loaded' || state == 'complete') {
                Event.domReady.callback();
            }
        }, 50);
         
        } else if (document.readyState && ie) {
             
            // Windows IE
            var src = (window.location.protocol == 'https:') ? '://0' : 'javascript:void(0)';
            document.write(
            '<script type="text/javascript" defer="defer" src="' + src + '" ' +
            'onreadystatechange="if (this.readyState == \'complete\') Event.domReady.callback();"' +
            '><\/script>');
             
        } else {
             
            if (window.addEventListener) {
                // for Mozilla browsers, Opera 9
                document.addEventListener("DOMContentLoaded", Event.domReady.callback, false);
                // Fail safe
                window.addEventListener("load", Event.domReady.callback, false);
            } else if (window.attachEvent) {
                window.attachEvent('onload', Event.domReady.callback);
            } else {
                // Legacy browsers (e.g. Mac IE 5)
                var fn = window.onload;
                window.onload = function() {
                    Event.domReady.callback();
                    if (fn) fn();
                }
            }
             
        }
     
    }
}