var DIR_IMAGES = "../img/main/";
var IMG_PLUS   = DIR_IMAGES + "pfeil_rechts.jpg";
var IMG_MINUS  = DIR_IMAGES + "pfeil_unten.jpg";
var IMG_LEER   = DIR_IMAGES + "leer.gif";

var imgPlus  = new Image();
imgPlus.src  = IMG_PLUS;
var imgMinus = new Image();
imgMinus.src = IMG_MINUS;
var imgLeer  = new Image();
imgLeer.src = IMG_LEER;

var objLocalTree = null;

var INDENT_WIDTH  = 5;
var PICTUR_WIDTH  = 0;
var PLUSMINUS_TXT = "Ein-/Ausklappen";

var HAS_PICTURE = false;

var TEXT_PASSIVE = "textItemList";
var TEXT_ACTIVE  = "textbold";


function hdtTree() {

    //Public Properties
    this.root = null;           //the root node of the tree
 
     //Public Collections
    this.nodes = new Array;     //array for all nodes in the tree
   
    //Constructor
    //assign to local copy of the tree
    objLocalTree = this;
}

hdtTree.prototype.createRoot = function(strText, strURL, strTarget) {

    //create a new node
    this.root = new hdtTreeNode(strText, strURL, strTarget);
    
    //assign an ID for internal tracking
    this.root.id = "root";
    
    //add it into the array of all nodes
    this.nodes["root"] = this.root;
    
    //make sure that the root is expanded
    this.root.expanded = true;

    //make sure that the root is not highlighted
    this.root.highlight = false;
    
    //return the created node
    return this.root;
}

function hdtTreeNode(strText, strURL, strTarget) {

    //Public Properties
    this.text   = strText;          //the text to display
    this.url    = strURL;           //the URL to link to
    this.target = strTarget;        //the target for the URL
    
    //Private Properties
    this.indent = 0;                //the indent for the node
    
    //Public States
    this.expanded = false;          //is this node expanded?
    
    this.highlight = false;         // ist das highlight an?
 
    //Public Collections   
    this.childNodes = new Array;    //the collection of child nodes
}

hdtTreeNode.prototype.addChild = function (strText, strURL, strTarget) {

    //create a new node
    var objNode = new hdtTreeNode(strText, strURL, strTarget);
    
    //assign an ID for internal tracking: root_1_1...
    objNode.id = this.id + "_" + this.childNodes.length;
    
    //assign the indent for this node
    objNode.indent = this.indent + 1;
    
    //add into the array of child nodes
    this.childNodes[this.childNodes.length] = objNode;
    
    //add it into the array of all nodes
    objLocalTree.nodes[objNode.id] = objNode;
    
    //return the created node
    return objNode;
}

hdtTree.prototype.buildDOM = function(domLevel) {

    //call method to add root to document, which will recursively
    //add all other nodes
    this.root.addToDOM(domLevel);
}

hdtTreeNode.prototype.addToDOM = function (objDOMParent) {
    //create the URL
    var strHTMLLink = "<a class=\"" + TEXT_PASSIVE + "\" href=\"" + this.url + "\"";
    if (this.target)strHTMLLink += " target=\"" + this.target + "\"><span class=\"" + TEXT_PASSIVE + "\">";
    
    //create the layer for the node
    var objNodeDiv = document.createElement("div");
    objNodeDiv.setAttribute("id", "master_" + this.id);
    
    //add it to the DOM parent element
    objDOMParent.appendChild(objNodeDiv);
    
	if(this.id != "root") {
		//create string buffer
		var d = new hdtDocument;
		
		//begin the table
		d.writeln("<table bgcolor=\"#EEEEEE\" border=\"0\" cellpadding=\"3\" cellspacing=\"0\"><tr bgcolor=\"#EEEEEE\" >");
		
		//no indent needed for root or level under root
		if (this.indent > 1) {
			d.write("<td bgcolor=\"#EEEEEE\" width=\"");
			d.write(this.indent * INDENT_WIDTH);
			d.write("\">");
			d.write("<img src=\"");
			d.write(imgLeer.src);
			d.write("\" border=\"0\" width=\"");
			d.write(this.indent * INDENT_WIDTH);
			d.write("\" height=\"1\" alt=\"\" id=\"\" />");
			d.write("</td>");
		}
		
		//there is no plus/minus image for the root
		if (this.indent > 0) {
		
			d.write("<td bgcolor=\"#EEEEEE\" width=\"");
			d.write(INDENT_WIDTH);
			d.write("\" valign=\"top\" align=\"center\">");
			
			//if there are children, then add a plus/minus image
			if (this.childNodes.length > 0) {
				d.write("<a href=\"javascript:objLocalTree.toggleExpand('");
				d.write(this.id);
				d.write("')\"><img src=\"");
				d.write(this.expanded ? imgMinus.src : imgPlus.src);
				d.write("\" border=\"0\" hspace=\"1\" id=\"");
				d.write("imgPM_" + this.id);
				d.write("\" alt=\"");
				d.write(PLUSMINUS_TXT);
				d.write("\" title=\"");
				d.write(PLUSMINUS_TXT);
				d.write("\" /></a>");
			} else {
				// Zelle ist leer
				d.write("<img src=\"");
				d.write(imgLeer.src);
				d.write("\" border=\"0\" width=\"9\" height=\"1\" alt=\"\" id=\"\" />");
			}
			
			d.write("</td>");
		}
	
		//finish by drawing the text
		d.write("<td bgcolor=\"#EEEEEE\">" + strHTMLLink + this.text + "</span></a></td>");
		d.writeln("</tr></table>");
		  
		//assign the HTML to the layer
		objNodeDiv.innerHTML = d;
    }
    //create the layer for the children
    var objChildNodesLayer = document.createElement("div");
    objChildNodesLayer.setAttribute("id", "divChildren_" + this.id);
    objChildNodesLayer.style.position = "relative";
    objChildNodesLayer.style.display = (this.expanded ? "block" : "none");
    objNodeDiv.appendChild(objChildNodesLayer);
    
    //call for all children (rekursiv)
    for (var i=0; i < this.childNodes.length; i++)
        this.childNodes[i].addToDOM(objChildNodesLayer);
}

hdtTree.prototype.toggleHighlight = function(strNodeID) {
    //get the node
    var objNode             = this.nodes[strNodeID];
	var myElements          = document.getElementById("master_" + objNode.id);
	var myCell              = myElements.getElementsByTagName("table");
	var myCellTable         = myCell.item(0);
	var myCellTableElements = myCellTable.getElementsByTagName("tr");
	var myCellTR            = myCellTableElements.item(0);
	var myCellTRElements    = myCellTR.getElementsByTagName("td");
	var myCellTD            = myCellTRElements.item(myCellTRElements.length -1);
	var myCellSPElements    = myCellTD.getElementsByTagName("span");
	var myCellSP            = myCellSPElements.item(0);
	var myCellAElements     = myCellTD.getElementsByTagName("a");
	var myCellA             = myCellAElements.item(0);
	
    if (objNode.highlight) {
    	objNode.highlight = false;
        //myCellTD.style.backgroundColor = "#000";
    	//myCellSP.setAttribute("class", TEXT_PASSIVE);
    	//myCellA.setAttribute("class", TEXT_PASSIVE);
    	myCellSP.style.fontWeight = "normal";
	} else {   
    	objNode.highlight = true;
        // myCellSP.style.backgroundColor = "#AAA";
    	//myCellSP.setAttribute("class", "textany"); //TEXT_ACTIVE   fontWeight
    	myCellSP.style.fontWeight = "bold";
    	//myCellA.setAttribute("class", "textany"); //TEXT_ACTIVE
    }
}

hdtTree.prototype.toggleExpand = function(strNodeID) {

    //get the node
    var objNode = this.nodes[strNodeID];
    
    //determine whether to expand or collapse
    if (objNode.expanded)
        objNode.collapse();
    else
        objNode.expand();
}

hdtTreeNode.prototype.collapse = function () {

    //check to see if the node is already collapsed
    if (!this.expanded) {
    
        //throw an error
        throw "Node is already collapsed";

    } else {
    
        //change the state of the node
        this.expanded = false;
        
        //change the plus/minus image to be plus
        document.images["imgPM_" + this.id].src = imgPlus.src;
        
        //hide the child nodes
        document.getElementById("divChildren_" + this.id).style.display = "none";
    }
}

hdtTreeNode.prototype.expand = function () {

    //check to see if the node is already expanded
    if (this.expanded) {
    
        //throw an error
        throw "Node is already expanded";
    
    } else {
    
        //change the state of the node
        this.expanded = true;
        
        //change the plus/minus image to be minus
        document.images["imgPM_" + this.id].src = imgMinus.src;
        
        //show the child nodes
        document.getElementById("divChildren_" + this.id).style.display = "block";
    }
}

/*>>>>>>>
Die folgende Funktion setzt nachtraeglich die Attribute "alt" und "title" auf "Ein-/Ausklappen".
	Beispiel-Aufruf: 
setHDTTreeAltTitleAttributesToPlusMinusText();
	Rueckgabewert: 
keiner
<<<<<<<*/
setHDTTreeAltTitleAttributesToPlusMinusText = function(){
	var links = document.getElementsByTagName("a");
	for(var index = 0; index < links.length; ++index){
		var link = links.item(index);
		if(link.href.substring(0, 36) == 'javascript:objLocalTree.toggleExpand'){
		  link.setAttribute('title', PLUSMINUS_TXT);
		  link.setAttribute('alt'  , PLUSMINUS_TXT);
		}
	}
}