// ===================================================================
// Author: Matt Kruse <matt@mattkruse.com>
// WWW: http://www.mattkruse.com/
//

setDefault("treeClass","mktree");
setDefault("nodeClosedClass","liClosed");
setDefault("nodeOpenClass","liOpen");
setDefault("nodeBulletClass","liBullet");
setDefault("nodeLinkClass","bullet");
setDefault("preProcessTrees",true);

// 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;
        }
}

// Full 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() {
        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);
                }
        }
}