/*
aqtree3.js

Converts an unordered list to an explorer-style tree


To make this work, simply add one line to your HTML:

<script type="text/javascript" src="aqtree3.js">
</script>

and then make the top UL of your nested unordered list of class "aqtree3".


That's it. 
No registration function, nothing.


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)

*/


addEvent(window, "load", makeTrees);



function makeTrees() {
    // We don't actually need createElement, but we do

                          // need good DOM support, so this is a good check.

    if (!document.createElement) return;


    uls = document.getElementsByTagName("ul");

    for (uli=0;uli<uls.length;uli++) {

        ul = uls[uli];

        if (ul.nodeName == "UL" && ul.className == "aqtree3") {

            processULEL(ul);

        }

    }

}



function processULEL(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 a;

            var subul;

	    subul = "";

            for (var sitemi=0;sitemi<item.childNodes.length;sitemi++) {

                var sitem = item.childNodes[sitemi];

                switch (sitem.nodeName) {

                    case "A": a = sitem; break;

                    case "UL": subul = sitem;

                               processULEL(subul);

                               break;

                }

            }

            if (subul) {

                associateEL(a,subul);

            } else {

                a.parentNode.style.listStyleImage = "url(bullet.gif)";

            }

        }

    }

}



function associateEL(a,ul) {

    a.onclick = function () {

        var display = ul.style.display;

        this.parentNode.style.listStyleImage = (display == "block") ? "url(plus.gif)" : "url(minus.gif)";

        ul.style.display = (display == "block") ? "none" : "block";

        return false;

    }

    a.onmouseover = function() {

        var display = ul.style.display;

        window.status = (display == "block") ? "Collapse" : "Expand";
	return true;

    }

    a.onmouseout = function() {

        window.status = "";

	return true;

    }

}



/*              Utility functions                    */


function addEvent(obj, evType, fn){

  /* adds an eventListener for browsers which support it

     Written by Scott Andrew: nice one, Scott */

  if (obj.addEventListener){

    obj.addEventListener(evType, fn, false);

    return true;

  } else if (obj.attachEvent){

	var r = obj.attachEvent("on"+evType, fn);

    return r;

  } else {

	return false;

  }

}