/*
The MIT License

Copyright (c) 2007 SitePoint Pty. Ltd. http://www.sitepoint.com/

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/


var Core = {};

    // W3C DOM 2 Events Model
if (document.addEventListener)
{
    Core.addEventListener = function(target, type, listener) { target.addEventListener(type, listener, false); };

    Core.removeEventListener = function(target, type, listener) { target.removeEventListener(type, listener, false); };

    Core.preventDefault = function(event) { event.preventDefault(); };

    Core.stopPropagation = function(event) { event.stopPropagation(); };
}
    // Internet Explorer Events Model
else if (document.attachEvent)
{
    Core.addEventListener = function(target, type, listener)
    {
            // Prevent adding the same listener twice, since DOM 2 Events
            // ignores duplicates like this.
        if (Core._findListener(target,type,listener) != -1)
            return;

            // listener2 calls listener as a method of target in one of two
            // ways, depending on what this version of IE supports, and
            // passes it the global event as an argument.
        var listener2 = function()
        {
            var event = window.event;

            if (Function.prototype.call)
            {
                listener.call(target, event);
            }
            else
            {
                target._currentListener = listener;
                target._currentListener(event);
                target._currentListener = null;
            }
        };

            // Add listener2 using IE's attachEvent method.
        target.attachEvent("on" + type, listener2);

            // Create an object describing this listener so we can clean it up later.
        var listenerRecord =
        {
            target: target,
            type: type,
            listener: listener,
            listener2: listener2
        };

            // Get a reference to the window object containing target.
        var targetDocument  = target.document || target;
        var targetWindow    = targetDocument.parentWindow;

            // Create a unique ID for this listener.
        var listenerId = "1" + Core._listenerCounter++;

            // Store the record of this listener in the window object
        if (!targetWindow._allListeners) targetWindow._allListeners = {};
        targetWindow._allListeners[listenerId] = listenerRecord;

            // Store this listener's id in target
        if (!target._listeners) target._listeners = [];
        target._listeners[target._listeners.length] = listenerId;

            // Set up Core._removeAllListeners to clean up all listeners on unload
        if (!targetWindow._unloadListenerAdded)
        {
            targetWindow._unloadListenerAdded = true;
            targetWindow.attachEvent("onunload", Core._removeAllListeners);
        }
    };

    Core.removeEventListener = function(target, type, listener)
    {
            // Find out if the listener was actually added to target.
        var listenerIndex = Core._findListener(target, type, listener);
        if (listenerIndex == -1) return;

            // Get a reference to the window object containing target.
        var targetDocument = target.document || target;
        var targetWindow = targetDocument.parentWindow;

            // Obtain the record of the listener from the window object.
        var listenerId = target._listeners[listenerIndex];
        var listenerRecord = targetWindow._allListeners[listenerId];

            // Remove the listener and remove its ID from target
        target.detachEvent("on" + type, listenerRecord.listener2);
        target._listeners.splice(listenerIndex, 1);

            // Remove the record of the listener from the window object.
        delete targetWindow._allListeners[listenerId];
    };

    Core.preventDefault = function(event) { event.returnValue = false; };

    Core.stopPropagation = function(event) { event.cancelBubble = true; };

    Core._findListener = function(target, type, listener)
    {
            // Get the array of listener IDs added to target
        var listeners = target._listeners;
        if (!listeners) return -1;

            // Get a reference to the window object containing target
        var targetDocument = target.document || target;
        var targetWindow = targetDocument.parentWindow;

            // Searching backward to (speed up onunload processing), find the listener.
        for (var i = listeners.length -1; i >= 0; i--)
        {
                // Get the listener's ID from target.
            var listenerId = listeners[i];

                // Get the record of the listener from the window object
            var listenerRecord = targetWindow._allListeners[listenerId];

                // Compare type and listener with the retrieved record
            if (listenerRecord.type == type && listenerRecord.listener == listener) return i;
        }
        return -1;
    };

    Core._removeAllListeners = function()
    {
        var targetWindow = this;
        for (id in targetWindow._allListeners)
        {
            var listenerRecord = targetWindow._allListeners[id];
                listenerRecord.target.detachEvent("on" + listenerRecord.type, listenerRecord.listener2);
            delete targetWindow._allListeners[id];
        }
    };

    Core._listenerCounter = 0;
}

Core.getElementsByClass = function(theClass)
{
    var elementArray = [];

    if (typeof document.all != "undefined") {
        elementArray = document.all;
    }
    else {
        elementArray = document.getElementsByTagName("*");
    }

    var matchedArray = [];
    var pattern = new RegExp("(^| )" + theClass + "( |$)");

    for (var i = 0; i < elementArray.length; i++) {
        if (pattern.test(elementArray[i].className)) {
            matchedArray[matchedArray.length] = elementArray[i];
        }
    }
    return matchedArray;
};

Core.hasClass = function(target, theClass)
{
    var pattern = new RegExp("(^| )" + theClass + "( |$)");
    if (pattern.test(target.className)) return true;
    return false;
};

Core.addClass = function(target, theClass)
{
    if (!Core.hasClass(target, theClass)) {
        if (target.className == "") {
            target.className = theClass;
        }
        else {
            target.className += " " + theClass;
        }
    }
};

Core.removeClass = function(target, theClass)
{
    var pattern = new RegExp("(^| )" + theClass + "( |$)");
    target.className = target.className.replace(pattern, "$1");
    target.className = target.className.replace(/ $/, "");
};

Core.getComputedStyle = function(element, styleProperty)
{
    var computedStyle = null;

    if (typeof element.currentStyle != "undefined") {
        computedStyle = element.currentStyle;
    }
    else {
        computedStyle = document.defaultView.getComputedStyle(element, null);
    }
    return computedStyle[styleProperty];
};

// Initialize Core
Core.start = function(runnable)
{
   Core.addEventListener(window, "load", runnable.init);
};