/* Copyright © 2002 Jean-Claude Manoli [jc@manoli.net]
 *
 * This software is provided 'as-is', without any express or implied warranty.
 * In no event will the author(s) be held liable for any damages arising from
 * the use of this software.
 * 
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 * 
 *   1. The origin of this software must not be misrepresented; you must not
 *      claim that you wrote the original software. If you use this software
 *      in a product, an acknowledgment in the product documentation would be
 *      appreciated but is not required.
 * 
 *   2. Altered source versions must be plainly marked as such, and must not
 *      be misrepresented as being the original software.
 * 
 *   3. This notice may not be removed or altered from any source distribution.
 */ 

var treeSelected = null; //last treeNode clicked

//pre-load tree nodes images
var imgPlus = new Image();
imgPlus.src="/images/treenodeplus.gif";
var imgMinus = new Image();
imgMinus.src="/images/treenodeminus.gif";
var imgDot = new Image();
imgDot.src="/images/treenodedot.gif";

var nodeVisible = "treeNode";
var nodeHidden  = "treeSubnodesHidden";

function findNode(el)
{
// Takes element and determines if it is a treeNode.
// If not, seeks a treeNode in its parents.
    while (el != null)
    {
        if (el.className == "treeNode")
        {
            break;
        }
        else
        {
            el = el.parentNode;
        }
    }
    return el;
}


function clickAnchor(el)
{
// handles click on a TOC link
//
    expandNode(el.parentNode);
    selectNode(el.parentNode);
    el.blur();
}


function selectNode(el)
{
// Un-selects currently selected node, if any, and selects the specified node
//
    if (treeSelected != null)
    {
        setSubNodeClass(treeSelected, 'A', 'treeUnselected');
    }
    setSubNodeClass(el, 'A', 'treeSelected');
    treeSelected = el;
}


function setSubNodeClass(el, nodeName, className)
{
// Sets the specified class name on el's first child that is a nodeName element
//
    var child;
    for (var i=0; i < el.childNodes.length; i++)
    {
        child = el.childNodes[i];
        if (child.nodeName == nodeName)
        {
            child.className = className;
            break;
        }
    }
}


function expandCollapse(el)
{
    el = el.parentNode;
    
//  If source treeNode has child nodes, expand or collapse view of treeNode
//
    if (el == null)
        return; //Do nothing if it isn't a treeNode
        
    var child;
    var imgEl;
    for(var i=0; i < el.childNodes.length; i++)
    {
        child = el.childNodes[i];
        if (child.src)
        {
            imgEl = child;
        }
        else if (child.className == "treeSubnodesHidden")
        {
            child.className = "treeSubnodes";
            imgEl.src = imgMinus.src;
            break;
        }
        else if (child.className == "treeSubnodes")
        {
            child.className = "treeSubnodesHidden";
            imgEl.src = imgPlus.src;
            break;
        }
    }
}


function expandNode(el)
{
//  If source treeNode has child nodes, expand it
//
    var child;
    var imgEl;
    for(var i=0; i < el.childNodes.length; i++)
    {
        child = el.childNodes[i];
        if (child.src)
        {
            imgEl = child;
        }
        if (child.className == "treeSubnodesHidden")
        {
            child.className = "treeSubnodes";
            imgEl.src = imgMinus.src;
            break;
        }
    }
}


function syncTree(href)
{
// Selects and scrolls into view the node that references the specified URL
//
    var loc = new String();
    loc = href;
    if (loc.substring(0, 7) == 'file://')
    {
        loc = 'file:///' + loc.substring(7, loc.length);
        loc = loc.replace(/\\/g, '/');
    }
    
    var base = loc.substr(0, loc.lastIndexOf('/') + 1);
    
    var tocEl = findHref(document.getElementById('treeRoot'), loc, base);
    if (tocEl != null)
    {
        selectAndShowNode(tocEl);
    }
}

function findHref(node, href, base)
{
// find the <a> element with the specified href value
//
    var el;
    var anchors = node.getElementsByTagName('A');
    for (var i = 0; i < anchors.length; i++)
    {
        el = anchors[i];
        var aref = new String();
        aref = el.getAttribute('href');
        
        if ((aref.substring(0, 7) != 'http://') 
            && (aref.substring(0, 8) != 'https://')
            && (aref.substring(0, 7) != 'file://'))
        {
            aref = base + aref;
        }
        
        if (aref == href)
        {
            return el;
        }
    }
    return null;
}

function selectAndShowNode(node)
{
// Selects and scrolls into view the specified node
//
    var el = findNode(node);
    if (el != null) 
    {
        selectNode(el);
        do 
        {
            expandNode(el);
            el = findNode(el.parentNode);
        } while ((el != null))  
        
        //vertical scroll element into view
        var windowTop;
        var windowBottom;
        var treeDiv = document.getElementById('tree');
        
        var ua = window.navigator.userAgent.toLowerCase();
        if ((i = ua.indexOf('msie')) != -1)
        {
            windowTop = node.offsetTop - treeDiv.scrollTop;
            windowBottom = treeDiv.clientHeight - windowTop - node.offsetHeight;
        }
        else if (ua.indexOf('gecko') != -1)
        {
            windowTop = node.offsetTop - treeDiv.offsetTop - treeDiv.scrollTop;
            windowBottom = treeDiv.clientHeight - windowTop - node.offsetHeight;
        }
        else 
        {
            return;
        }
        
        if (windowTop < 0)
        {
            treeDiv.scrollTop += windowTop - 18;
            return;
        }
        if (windowBottom < 0)
        {
            treeDiv.scrollTop -= windowBottom - 18;
            return;
        }
    }
}


function resizeTree()
{
    var treeDiv = document.getElementById('tree');
    //treeDiv.setAttribute('style', 'width: ' + document.body.offsetWidth + 'px; height: ' + (document.body.offsetHeight - 27) + 'px;');
    treeDiv.style.width = document.documentElement.offsetWidth;
    treeDiv.style.height = document.documentElement.offsetHeight - 27;
}