/**
* 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/index.html') > -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 == 'default.html') ? '://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();
                }
            }

        }

    }
}