/* XML functions */
function verify() {
	// 0 Object is not initialized
	// 1 Loading object is loading data
	// 2 Loaded object has loaded data
	// 3 Data from object can be worked with
	// 4 Object completely initialized
	if (xmlDoc.readyState != 4) {
		return false;
	}
}
function stripWhitespaceDoublePass (theNode) {
//alert("stripWhitespaceDoublePass invoked. theNode="+theNode);
	// Loop through all children of theNode
	for ( var i=0; i<theNode.childNodes.length; i++) {
		// if the current node is a text node...
		if (theNode.childNodes[i].nodeType ==3) {
			// Check for any useful chars in the code
			var j=0;
			var emptyNode = true;
			for (j=0; j < theNode.childNodes[i].nodeValue.length; j++ ){
				if (theNode.childNodes[i].nodeValue.charCodeAt(j) > 32) {
					emptyNode = false;
					break;
				}
			}
			// If no useful chars are found, delete the node
			if (emptyNode) theNode.removeChild(theNode.childNodes[i]);
		}
	}
	// Now that all whitespace nodes have been removed,
	// call this function recursively on remaining children
	for (var k=0; k < theNode.childNodes.length; k++) stripWhitespaceDoublePass(theNode.childNodes[k]);
}
function loadXML ( filename ) {
	// Assumptions: There is an XML file with the same name as the body.className
	//   of the html calling this.
	var xmlFile = xmlFolder + filename + '.xml';
	if (document.implementation && document.implementation.createDocument){
		// Mozilla
//alert("loadXML invoked. Browser is FF");
		xmlObj = document.implementation.createDocument("", "", null);
  		xmlObj.onload = function() {
			stripWhitespaceDoublePass(this);
			parseXML();}
  		xmlObj.load(xmlFile);
		//alert(xmlObj.nodeValue);
	} else if(window.ActiveXObject) {
		// IE
//alert("loadXML invoked. Browser is IE");
		xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
		xmlDoc.async="false";
		xmlDoc.onreadystatechange=verify;
		xmlDoc.load(xmlFile);
		xmlObj=xmlDoc.documentElement;
		parseXML();
	} else {
		// Browser unknown
		alert("Browser unknown");
	}
}
function getTagText ( searchElement, tagName ) {
	var tagArray = searchElement.getElementsByTagName( tagName );
	if ( tagArray.length > 0 ) {
		if ( tagArray[ 0 ].firstChild ){
			if ( tagArray[ 0 ].firstChild.nodeValue.length > 0 ){ return tagArray[ 0 ].firstChild.nodeValue; }
		}
	}
	return null;
}
function parseXML () {
	// Assumptions: There is a div named imageDisplay.
//alert("imageProjectXML invoked. xmlObj.firstChild.tagName="+xmlObj.firstChild.tagName);
	
	// If XML contains projects
	images = xmlObj.getElementsByTagName("image");

	if ( images.length > 0 ) {
		// Add new div for large image display
		var tDiv = document.createElement("div");
		tDiv.id = "imageDisplay";
		imagesDisplayDiv.appendChild(tDiv);
		imageDisplayDiv = document.getElementById("imageDisplay");
		
		// Add new div for thumbnail display
		var tDiv = document.createElement("div");
		tDiv.id = "thumbnails";
		imagesDisplayDiv.appendChild(tDiv);
		thumbnailsDiv = document.getElementById("thumbnails");

		// For every image listed in the XML, add them to the div
		for (var i=0; i < images.length; i++) {
			// Get the filename of the image
			var tName = getTagText( images[i], 'filename' );
			// Create A node
			var tAnode = document.createElement("a");
			tAnode.style.borderColor = thumbNormal;
			tAnode.setAttribute( "name", i);
			tAnode.onclick  = function () {
				resetThumbBorders(thumbnailsDiv);
				this.style.borderColor = thumbActive;
				this.firstChild.style.visibility = "hidden";
				displayImage(this.name); 
				return false;
			}
			tAnode.onmouseover  = function () {
				if (this.firstChild.style.visibility!="hidden") {
					this.style.borderColor = thumbHover;
				}
			}
			tAnode.onmouseout  = function () {
				if (this.firstChild.style.visibility!="hidden") {
					this.style.borderColor = thumbNormal;
				}
			}
			// Create IMG node
			var tImg = document.createElement("img");
			tImg.src=thumbLocation+tName+thumbType;
			tAnode.appendChild(tImg);
			thumbnailsDiv.appendChild(tAnode);

			// Set correct feedback
			if (i==0) {
				tAnode.style.borderColor = thumbActive;
				tAnode.firstChild.style.visibility = "hidden";
				imageDisplayDiv.style.backgroundImage = "url("+fileLocation+tName+fileType+")";
			}
		}// endFor every image
	}// endif XML contains images
}
///// The background image for the Anode is the thumbnail!!!
function removeChildrenFromNode(nodeToClear) {
//alert("removeChildrenFromNode invoked.");
	//while(nodeToClear.firstChild) nodeToClear.removeChild(nodeToClear.firstChild);
}

function displayImage (nodeNumber) {
//alert("displayImage: nodeNumber="+nodeNumber);
	// Store selected project number
	imageNumber = nodeNumber;
	
	// Set pointer to the selected image
	var imageName = getTagText( images[ nodeNumber ], 'filename' );
	var imageFile = "url("+fileLocation+imageName+fileType+")";

	// Display default large image
	imageDisplayDiv.style.backgroundImage = imageFile;
	
	// Reset thumb borders
	resetThumbBorders( nodeNumber );
	
}
function resetThumbBorders ( nodeNumber ) {
//alert("resetThumbBorders invoked");
	// Get the array of thumbnails
	var thumbsToChange = thumbnailsDiv.getElementsByTagName("a");
	// How many thumbmails are there?
	var numThumbs = thumbsToChange.length;
	for ( var i=0; i<numThumbs; i++ ) {
		if ( i!=nodeNumber) {
			thumbsToChange[i].style.borderColor = thumbNormal;
			thumbsToChange[i].firstChild.style.visibility = "visible";
		} else {
			thumbsToChange[i].style.borderColor = thumbActive;
			thumbsToChange[i].firstChild.style.visibility = "hidden";
		}
	}
}