/*
 * 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;
  }
}