var currentPreview = null;
var currentHeight = 0;

var images = new Array();

function displayPreview(event, pos, which) {
	if(currentPreview==which)
		return;
	currentPreview = which;
	if(pos==0) {
		var preview = document.getElementById("left-preview");
		var title = document.getElementById("left-preview-title");
		var text = document.getElementById("left-preview-text");
	} else {
		var preview = document.getElementById("right-preview");
		var title = document.getElementById("right-preview-title");
		var text = document.getElementById("right-preview-text");
	}
	title = killChildren(title);
	text = killChildren(text);
	if(!contentArray[which]) {
		title.appendChild(document.createTextNode(which));
		text.appendChild(document.createTextNode('unknown key'));
	} else {
		title.appendChild(document.createTextNode(contentArray[which][0]));
		var p = document.createElement('p');
		p.appendChild(document.createTextNode(contentArray[which][1]));
		text.appendChild(p);
		if(contentArray[which][2]) {
			var img = document.createElement('img');
			img.src = images[contentArray[which][2]].src;
			img.setAttribute("alt", "Screenshot of "  + contentArray[which][0]);
			text.appendChild(img);
		}
	}
	preview.style.display = "block";
	currentHeight = parseInt(preview.offsetHeight);
	movePreview(event, pos);
}

function movePreview(event, pos) {
	if(pos==0) {
		var preview = document.getElementById("left-preview");
	} else {
		var preview = document.getElementById("right-preview");
	}
	ev = event || window.event;
	top = ev.pageY - currentHeight/2;
	preview.style.top = top + "px";
}

function vanishPreview() {
	currentPreview = null;
	currentHeight = 0;
	document.getElementById("left-preview").style.display = 'none';
	document.getElementById("right-preview").style.display = 'none';
	killChildren(document.getElementById("left-preview-title"));
	killChildren(document.getElementById("right-preview-title"));
	killChildren(document.getElementById("left-preview-text"));
	killChildren(document.getElementById("right-preview-text"));
}

function killChildren(el) {
	while(el.firstChild) {
		el.removeChild(el.firstChild);
	}
	return el;
}

function preloadImage(img) {
	if(document.images) {
		images[img] = new Image();
		images[img].src = 'thumbs/' + img;
	}
}

function init() {
	for(i in contentArray) {
		if(contentArray[i][2]) {
			preloadImage(contentArray[i][2]);
		}
	}
}