/**
* 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();
                }
            }
            
        }
        
    }
}