/*
 * aScroller js
 * 
 * Copyright (C) 2005-2006
 * by Davide S. Casali
 * www.digitalhymn.com
 *
 * Last release: 2005-11-27
 *
 * Released under CC by-nc-sa 2.5
 * http://creativecommons.org/licenses/by-nc-sa/2.5/
 *
 */

/*
 * This is a simple JavaScript vertical scroller that is crossbrowser and also validates
 * as XHTML Strict.
 *
 * Usage:
 * (1) Define a <div> tag with a specified ID, containing the scrolling text. One <div> for each line.
 * (2) Define an INLINE CSS width and height (important, MUST be inline)
 * (3) Execute the divScroller function, passing id, mode (h or v),  speed (higher number means
 *     slower) and delay (in ms).
 *
 */

/****************************************************************************************************
 * Cross browser getElementByID.
 * From: www.quirksmode.org
 *
 * @param    id
 */
function getObj(name)
{
    if (document.getElementById)
    {
        this.obj = document.getElementById(name);
        this.style = document.getElementById(name).style;
    }
    else if (document.all)
    {
        this.obj = document.all[name];
        this.style = document.all[name].style;
    }
    else if (document.layers)
    {
        this.obj = document.layers[name];
        this.style = document.layers[name];
    }
}

/****************************************************************************************************
 * Enables the scrolling for the specified div (matching id).
 *
 * @param    string id of the tag
 * @param    speed
 * @param    delay
 */
function divScroller(id, direction, speed, delay)
{
    if (document.getElementById)
    {
        // DOM3 = IE5+, NS6+, FF0.7+
        // *** Scroller
        var scroller = new getObj(id);
        
        // *** Debug force vars
        //scroller.style.height = "30px";
        //scroller.style.backgroundColor = "#FFEEEE";
        
        // *** Computed Styles
        //alert(scroller.obj.currentStyle.height);
        /*if (!scroller.style.height)
            if (scroller.obj.currentStyle)
                scroller.style.height = scroller.obj.currentStyle.height;
            else
                scroller.style.height = document.defaultView.getComputedStyle(scroller.obj, null).getPropertyValue("height");*/
        
        // *** Needed vars
        scroller.style.position = "relative";
        scroller.style.overflow = "hidden";
        
        // *** Generate scrolling inner <div>
        scroller.obj.innerHTML = "<div id=\"" + id + "_inner\">" + scroller.obj.innerHTML + "</div>";
        
        // *** Inner
        var inner = new getObj(id + "_inner");
        inner.style.position = "absolute";
        inner.style.left = parseInt(scroller.style.width) + "px";
        inner.style.top = parseInt(scroller.style.height) + "px";
        
        // *** Apply sub-styles
        //divScrollItemsStyler(id, direction);
        
        // *** Worker
        if (direction == "h" || direction == "horizontal")
        {
            // ****** HORIZONTAL
            // MouseOver: pauses the ticker
            scroller.obj.onmouseover = function() { divScroll_onMouseOver(id); };
            scroller.obj.onmouseout = function() { divScroll_onMouseOut(id); };
            
            // Create a temp element to evaluate the size (awful, but no better way to do this)
            fxpatch = navigator.userAgent.indexOf("Firefox") > -1 ? " left: -9000px;" : ""; // Firefox different CSS (on every other browser since IE5+ isn't needed)
            spanContent = "<span id=\"" + id + "_widthEval\" style=\"visibility: hidden; position: absolute; top: -100px; left: -1px; z-index: -10; white-space: nowrap;" + fxpatch + "\"><nobr>" + inner.obj.innerHTML + "</nobr></span>";
            if (document.createElement)
            {
                var span = document.createElement('span');
                span.innerHTML = spanContent;
                scroller.obj.appendChild(span);
            }
            else
            {
                document.write(spanContent);
            }
            var widthEval = new getObj(id + "_widthEval");
            
            // Setup the scrolling inner drawer
            inner.style.top = "0px";
            inner.style.whiteSpace = "nowrap";
            inner.style.width = widthEval.obj.offsetWidth + "px";
            limit = parseInt(inner.style.width);
            
            // Execute
            setTimeout("divScrollHelperH(\"" + id + "\", " + limit + ", " + speed + ", " + delay + ")", parseInt(speed));
        }
        else if (direction == "v" || direction == "vertical")
        {
            // ****** VERTICAL
            // Setup the scrolling inner drawer
            inner.style.left = "0px";
            inner.style.width = parseInt(scroller.style.width) + "px";
            limit = inner.obj.getElementsByTagName('div').length * parseInt(scroller.style.height);
            
            // Execute
            setTimeout("divScrollHelperV(\"" + id + "\", " + limit + ", " + speed + ", " + delay + ")", parseInt(speed));
        }
    }
}

/****************************************************************************************************
 * Helper for the HORIZONTAL scrolling for the specified div (matching id).
 * This is the real "ticker" function, executed to move the div.
 *
 * @param    string id of the tag
 * @param    pre-calculated height limit (to speed up execution)
 * @param    speed
 * @param    delay
 */
function divScrollHelperH(id, limit, speed, delay)
{
    if (document.getElementById)
    {
        // DOM3 = IE5+, NS6+, FF0.7+
        var scroller = new getObj(id);
        var inner = new getObj(id + "_inner");
        
        // *** Tick duration
        nextTick = speed;
        
        // *** Avoiding some errors
        if (!inner.style.left) inner.style.left = "0px";
        
        // *** Moving the inner div. At the end, restart.
        if (parseInt(inner.style.left) < -limit)
        {
            inner.style.left = parseInt(scroller.style.width) + "px";
        }
        else if (!scroller.obj.pause || scroller.obj.pause == false)
        {
            inner.style.left = (parseInt(inner.style.left) - 1) + "px";
            
            // Deceiving Opera8 stupidity
            //inner.style.width = parseInt(scroller.style.width) - (parseInt(inner.style.left) - 4) + "px";
        }
        
        // *** Bigger delay on item found
        // Skips borders to make transition without delays on loop
        /*if (!(parseInt(inner.style.left) == parseInt(scroller.style.width)) &&
            !(parseInt(inner.style.left) == -limit) &&
            (parseInt(inner.style.left) % parseInt(scroller.style.width)) == 0)
        {
            nextTick = delay;
        }*/
        
        // *** Tick!
        setTimeout("divScrollHelperH(\"" + id + "\", " + limit + ", " + speed + ", " + delay + ")", parseInt(nextTick));
    }
}

/****************************************************************************************************
 * Helper for the VERTICAL scrolling for the specified div (matching id).
 * This is the real "ticker" function, executed to move the div.
 *
 * @param    string id of the tag
 * @param    pre-calculated height limit (to speed up execution)
 * @param    speed
 * @param    delay
 */
function divScrollHelperV(id, limit, speed, delay)
{
    // DOM3 = IE5+, NS6+, FF0.7+
    var scroller = new getObj(id);
    var inner = new getObj(id + "_inner");
    
    // *** Tick duration
    nextTick = speed;
    
    // *** Avoiding some errors
    if (!inner.style.top) inner.style.top = "0px";
    
    // *** Moving the inner div. At the end, restart.
    if (parseInt(inner.style.top) < -limit)
    {
        inner.style.top = parseInt(scroller.style.height) + "px";
    }
    else
    {
        inner.style.top = (parseInt(inner.style.top) - 1) + "px";
    }
    
    // *** Bigger delay on item found
    // Skips borders to make transition without delays on loop
    if (!(parseInt(inner.style.top) == parseInt(scroller.style.height)) &&
        !(parseInt(inner.style.top) == -limit) &&
        (parseInt(inner.style.top) % parseInt(scroller.style.height)) == 0)
    {
        nextTick = delay;
    }
    
    // *** Tick!
    setTimeout("divScrollHelperV(\"" + id + "\", " + limit + ", " + speed + ", " + delay + ")", parseInt(nextTick));
}

/****************************************************************************************************
 * OnMouseOver helper for the HORIZONTAL scrolling for the specified div (matching id).
 *
 * @param    string id of the tag
 */
function divScroll_onMouseOver(id)
{
    var scroller = new getObj(id);
    scroller.obj.pause = true;
}

function divScroll_onMouseOut(id)
{
    var scroller = new getObj(id);
    scroller.obj.pause = false;
}

/****************************************************************************************************
 * Apply essential working styles to each <div> inside the scroller.
 *
 * @param    string id of the inner div
 */
function divScrollItemsStyler(id, direction)
{
    // DOM3 = IE5+, NS6+, FF0.7+
    var scroller = new getObj(id);
    var inner = new getObj(id + "_inner");
    
    elements = inner.obj.getElementsByTagName('div');
    
    for (var i = 0; i < elements.length; i++)
    {
        var item = elements.item(i);
        
        item.style.width = scroller.style.width;
    }
}