/* SWIM2.0 :: Simple website menu
****************************************************************
* DOM scripting by brothercake -- http://www.brothercake.com/
* Licensed under GPL -- http://www.gnu.org/copyleft/gpl.html
****************************************************************
* For professional menu solutions visit -- http://www.udm4.com/ 
****************************************************************
*/

//initialise the menu(s)
function genmenu()
  {
  //create a new menu ('menu-id', 'orientation')
  var verticals = new simpleMenu('menu-v', 'vertical');
  }

//menu object constructor
function simpleMenu(navid, orient)
  {
  //if the dom is not supported, or this is opera 5 or 6, don't continue
  if(typeof document.getElementById == 'undefined' || /opera[\/ ][56]/i.test(navigator.userAgent)) { return; }
  //identify konqueror
  this.iskde = navigator.vendor == 'KDE';
  //identify internet explorer [but both opera and konqueror recognise the .all collection]
  this.isie = typeof document.all != 'undefined' && typeof window.opera == 'undefined' && !this.iskde;
  isieglob = this.isie;
  //identify old safari [< 1.2]
  this.isoldsaf = navigator.vendor == 'Apple Computer, Inc.' && typeof XMLHttpRequest == 'undefined';
  //ul tree
  this.tree = document.getElementById(navid);

  //if it exists
  if(this.tree != null)
    {
    //get trigger elements
    this.items = this.tree.getElementsByTagName('li');
    this.itemsLen = this.items.length;
    //initialise each trigger, using do .. while because it's faster
    var i = 0; 
    do
      {
      this.init(this.items[i], this.isie, this.isoldsaf, this.iskde, navid, orient);
      }
    while (++i < this.itemsLen);
    }
  }

//trigger initialiser
simpleMenu.prototype.init = function(trigger, isie, isoldsaf, iskde, navid, ishoriz)
  {
  //store menu object, or null if there isn't one
  //extend it as a property of the trigger argument
  //so it's global within [and unique to] the scope of this instantiation
  //which is the same trick as going "var self = this"
  trigger.menu = trigger.getElementsByTagName('ul').length > 0 ? trigger.getElementsByTagName('ul')[0] : null;
  //store link object
  trigger.link = trigger.getElementsByTagName('a')[0];
  //store whther this is a submenu or child menu
  //a submenu's parent node will have the navbar id
  trigger.issub = trigger.parentNode.id == navid;
  //whether this is a horizontal navbar
  trigger.ishoriz = ishoriz == 'horizontal';
  //menu opening events
  //onfocus doesn't bubble in ie, but its proprietary 'onactivate' event does
  //which works in win/ie5.5+
  this.openers = { 'm' : 'onmouseover', 'k' : (isie ? 'onactivate' : 'onfocus') };
  //bind menu openers
  for(var i in this.openers)
    {
    trigger[this.openers[i]] = function(e)
      {
      //set rollover persistence classname -- we have to check for an existing value first
      //because some opera builds don't allow the class attribute to have a leading space
      //don't do persistent rollovers for konqueror, because they stick in kde <= 3.0.4
      if(!iskde) { trigger.link.className += (trigger.link.className == '' ? '' : ' ') + 'rollover'; }
      //if trigger has a menu
      if(trigger.menu != null)
        {
        //show the menu by positioning it back on the screen
        //we can use the same positions as in pure CSS for most browsers ['css']
        //but we have to compute the positions for ie ['compute'] 
        //because it uses position:relative on <a> 
        //whereas the others have position:relative on <li>
        //we also need to use those values for old safari builds ['compute']
        //because the regular positioning doesn't work 
        //if this is a horizontal navbar
        //set the left position to auto [css] or compute a position [compute]
        if(trigger.ishoriz) { trigger.menu.style.left = (isie || isoldsaf) ? trigger.offsetLeft + 'px' : 'auto'; }
        //if this is a horizontal navbar and a first-level submenu 
        //set the top position to auto [css] or compute a position [compute]
        //otherwise set it to 0 [css] or compute a position [compute]
        trigger.menu.style.top = (trigger.ishoriz && trigger.issub) ? (isie || (trigger.ishoriz && isoldsaf)) ? trigger.link.offsetHeight + 'px' : 'auto' : (isie || (trigger.ishoriz && isoldsaf)) ? trigger.offsetTop + 'px' : '0';
        }
      };
    }
  //menu closing events
  //'ondeactivate' is the equivalent blur handler for 'onactivate'
  this.closers = { 'm' : 'onmouseout', 'k' : (isie ? 'ondeactivate' : 'onblur') };

  //bind menu closers
  for(i in this.closers)
    {
    trigger[this.closers[i]] = function(e)
      {
      //store event-related-target property
      this.related = (!e) ? window.event.toElement : e.relatedTarget;
      //if event came from outside current trigger branch
      if(!this.contains(this.related))
        {
        //reset rollover persistence classname; not for konqueror
        if(!iskde) { trigger.link.className = trigger.link.className.replace(/[ ]?rollover/g, ''); }
        //if trigger has a menu
        if(trigger.menu != null)
          {
          //hide menu using left for a horizontal menu, or top for a vertical
          trigger.menu.style[(trigger.ishoriz ? 'left' : 'top')] = trigger.ishoriz ? '-10000px' : '-100em';
          }
        }
      };
    }

  //contains method by jkd -- http://www.jasonkarldavis.com/
  //not necessary for ie because we're re-creating in ie-proprietary method
  //and it would throw errors in mac/ie5 anyway
  //not actually necessary for opera 7 either, because it's already implemented
  //but it won't do any harm, so spoofing doesn't matter
  if(!isie)
    {
    trigger.contains = function(node)
      {
      if (node == null) { return false; }
      if (node == this) { return true; }
      else { return this.contains(node.parentNode); }
      };
    }
  }