// ===================================================================
// Author: Matt Kruse <matt@mattkruse.com>
// WWW: http://www.mattkruse.com/
//
// NOTICE: You may use this code for any purpose, commercial or
// private, without any further permission from the author. You may
// remove this notice from your final code if you wish, however it is
// appreciated by the author if at least my web site address is kept.
//
// You may *NOT* re-distribute this code in any way except through its
// use. That means, you can include it in your product, or your web
// site, or any other form where the code is actually being used. You
// may not put the plain javascript up on your site for download or
// include it in your javascript libraries for download. 
// If you wish to share this code with others, please just point them
// to the URL instead.
// Please DO NOT link directly to my .js files from your site. Copy
// the files to your server and use them there. Thank you.
// ===================================================================

// HISTORY
// ------------------------------------------------------------------
// December 9, 2003: Added script to the Javascript Toolbox
// December 10, 2003: Added the preProcessTrees variable to allow user
//      to turn off automatic conversion of UL's onLoad
// March 1, 2004: Changed it so if a <li> has a class already attached
//      to it, that class won't be erased when initialized. This allows
//      you to set the state of the tree when painting the page simply
//      by setting some <li>'s class name as being "liOpen" (see example)
/*
This code is inspired by and extended from Stuart Langridge's aqlist code:
      http://www.kryogenix.org/code/browser/aqlists/
      Stuart Langridge, November 2002
      sil@kryogenix.org
      Inspired by Aaron's labels.js (http://youngpup.net/demos/labels/) 
      and Dave Lindquist's menuDropDown.js (http://www.gazingus.org/dhtml/?id=109)
*/

// Automatically attach a listener to the window onload, to convert the trees
addEvent(window,"load",convertTrees);

// Utility function to add an event listener
function addEvent(o,e,f){
   if (o.addEventListener){ o.addEventListener(e,f,true); return true; }
   else if (o.attachEvent){ return o.attachEvent("on"+e,f); }
   else { return false; }
}

// utility function to set a global variable if it is not already set
function setDefault(name,val) {
   if (typeof(window[name])=="undefined" || window[name]==null) {
      window[name]=val;
   }
}

// Fully expands a tree with a given ID
function expandTree(treeId) {
   var ul = document.getElementById(treeId);
   if (ul == null) { return false; }
   expandCollapseList(ul,nodeOpenClass);
}

// Fully collapses a tree with a given ID
function collapseTree(treeId) {
   var ul = document.getElementById(treeId);
   if (ul == null) { return false; }
   expandCollapseList(ul,nodeClosedClass);
}

// Expands enough nodes to expose an LI with a given ID
function expandToItem(treeId,itemId) {
   var ul = document.getElementById(treeId);
   if (ul == null) { return false; }
   var ret = expandCollapseList(ul,nodeOpenClass,itemId);
   if (ret) {
      var o = document.getElementById(itemId);
      if (o.scrollIntoView) {
         o.scrollIntoView(false);
      }
   }
}

// Performs 3 functions:
// a) Expand all nodes
// b) Collapse all nodes
// c) Expand all nodes to reach a certain ID
function expandCollapseList(ul,cName,itemId) {
   if (!ul.childNodes || ul.childNodes.length==0) { return false; }
   // Iterate LIs
   for (var itemi=0;itemi<ul.childNodes.length;itemi++) {
      var item = ul.childNodes[itemi];
      if (itemId!=null && item.id==itemId) { return true; }
      if (item.nodeName == "LI") {
         // Iterate things in this LI
         var subLists = false;
         for (var sitemi=0;sitemi<item.childNodes.length;sitemi++) {
            var sitem = item.childNodes[sitemi];
            if (sitem.nodeName=="UL") {
               subLists = true;
               var ret = expandCollapseList(sitem,cName,itemId);
               if (itemId!=null && ret) {
                  item.className=cName;
                  return true;
               }
            }
         }
         if (subLists && itemId==null) {
            item.className = cName;
         }
      }
   }
}

// Search the document for UL elements with the correct CLASS name, then process them
function convertTrees() {
   setDefault("treeClass","mktree");
   setDefault("nodeClosedClass","liClosed");
   setDefault("nodeOpenClass","liOpen");
   setDefault("nodeBulletClass","liBullet");
   setDefault("nodeLinkClass","bullet");
   setDefault("preProcessTrees",true);
   if (preProcessTrees) {
      if (!document.createElement) { return; } // Without createElement, we can't do anything
      uls = document.getElementsByTagName("ul");
      for (var uli=0;uli<uls.length;uli++) {
         var ul=uls[uli];
         if (ul.nodeName=="UL" && ul.className==treeClass) {
            processList(ul);
         }
      }
   }
}

// Process a UL tag and all its children, to convert to a tree
function processList(ul) {
   if (!ul.childNodes || ul.childNodes.length==0) { return; }
   // Iterate LIs
   for (var itemi=0;itemi<ul.childNodes.length;itemi++) {
      var item = ul.childNodes[itemi];
      if (item.nodeName == "LI") {
         // Iterate things in this LI
         var subLists = false;
         for (var sitemi=0;sitemi<item.childNodes.length;sitemi++) {
            var sitem = item.childNodes[sitemi];
            if (sitem.nodeName=="UL") {
               subLists = true;
               processList(sitem);
            }
         }
         var s= document.createElement("SPAN");
         var t= '\u00A0'; // &nbsp;
         s.className = nodeLinkClass;
         if (subLists) {
            // This LI has UL's in it, so it's a +/- node
            if (item.className==null || item.className=="") {
               item.className = nodeClosedClass;
            }
            // If it's just text, make the text work as the link also
            if (item.firstChild.nodeName=="#text") {
               t = t+item.firstChild.nodeValue;
               item.removeChild(item.firstChild);
            }
            s.onclick = function () {
               this.parentNode.className = (this.parentNode.className==nodeOpenClass) ? nodeClosedClass : nodeOpenClass;
               return false;
            }
         }
         else {
            // No sublists, so it's just a bullet node
            item.className = nodeBulletClass;
            s.onclick = function () { return false; }
         }
         s.appendChild(document.createTextNode(t));
         item.insertBefore(s,item.firstChild);
      }
   }
}