/*
 * 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
 *
 * @paramid
 */
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).
 *
 * @paramstring id of the tag
 * @paramspeed
 * @paramdelay
 */
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.
 *
 * @paramstring id of the tag
 * @parampre-calculated height limit (to speed up execution)
 * @paramspeed
 * @paramdelay
 */
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.
 *
 * @paramstring id of the tag
 * @parampre-calculated height limit (to speed up execution)
 * @paramspeed
 * @paramdelay
 */
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).
 *
 * @paramstring 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.
 *
 * @paramstring 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;
}
}