/*************************************************************************
 *
 * motionpack.js -- DIV motion (slide) control functionality
 *
 *        Author:  Kyle J. Sparks (kjs42 at kjsparks ... com)
 *         Begin:  Apr 20, 2008May 26, 2010
 *  Last Revised:  May 26, 2010
 *
 * $Id: $
 *
 * Largely drawn from public sources.  
 *************************************************************************/
 
var timerlen = 5;
var slideAniLen = 250;

var timerID = new Array();
var startTime = new Array();
var obj = new Array();
var endHeight = new Array();
var moving = new Array();
var dir = new Array();

function slideToggle(objname) {
    if(moving[objname])
      return;

    if(document.getElementById(objname).style.display != "none")
      slideup(objname);   
    else
      slidedown(objname);
}

function slidedown(objname){
    if(moving[objname])
      return;

    if(document.getElementById(objname).style.display != "none")
      return; // cannot slide down something that is already visible

    moving[objname] = true;
    dir[objname] = "down";
    startslide(objname);
}

function slideup(objname){
    if(moving[objname])
      return;

    if(document.getElementById(objname).style.display == "none")
      return; // cannot slide up something that is already hidden

    moving[objname] = true;
    dir[objname] = "up";
    startslide(objname);
}

function startslide(objname){
    obj[objname] = document.getElementById(objname);

    endHeight[objname] = parseInt(obj[objname].style.height);
    startTime[objname] = (new Date()).getTime();

    if(dir[objname] == "down"){
      obj[objname].style.height = "1px";
    }

    obj[objname].style.display = "block";

    if ((self.timerID == null) || (timerID.constructor != Array))
      timerID = Array();
    timerID[objname] = setInterval( function () { slidetick(objname); },timerlen);
}

function slidetick(objname){
    var elapsed = (new Date()).getTime() - startTime[objname];

    if (elapsed > slideAniLen)
      endSlide(objname)
    else {
      var d = Math.round(elapsed / slideAniLen * endHeight[objname]);
      if(dir[objname] == "up")
              d = endHeight[objname] - d;

      obj[objname].style.height = d + "px";
    }

    return;
}

function endSlide(objname){

    if (self.timerID && timerID[objname])
      clearInterval(timerID[objname]);

    if(dir[objname] == "up")
      obj[objname].style.display = "none";

    obj[objname].style.height = endHeight[objname] + "px";

    moving[objname] = false;
    
    if (!self.timerID)  
      return;
    
    delete(moving[objname]);
    delete(timerID[objname]);
    delete(startTime[objname]);
    delete(endHeight[objname]);
    delete(obj[objname]);
    delete(dir[objname]);

    return;
}