var thumbInt = null;
var aniInterval = 1;
var duration = 800;

prepareThumbs = function() {
	var defaultHeight = 16;
	var children = document.getElementsByTagName('UL')[0].childNodes;
	trigThumb = function() {if(thumbInt == null) {triggerThumb(this,defaultHeight);} return false;}
	for(var i = 0; i < children.length; i++) {
		if(children[i].tagName == 'LI') {
			ele = document.createElement('a');
			ele.setAttribute("href","#");
			ele.setAttribute("title","Εμφάνιση πληροφοριών");
			ele.setAttribute("tabindex",i+1)
			ele = children[i].insertBefore(ele, children[i].getElementsByTagName('p')[0]);
			ele.appendChild(children[i].getElementsByTagName('p')[0]);
			children[i].getElementsByTagName('A')[0].onclick = trigThumb;
			children[i].style.height = defaultHeight+"px";
		}
	}
}

triggerThumb = function(element, defaultHeight) {
	element = element.parentNode;
	var inHeight = element.scrollHeight;
	var outHeight = element.offsetHeight;
	startTime = (new Date).getTime();
	openThumb = function() {animate(element, defaultHeight, inHeight+10);}
	closeThumb = function() {animate(element, inHeight, defaultHeight);}
	if(inHeight > outHeight) {
		thumbInt = setInterval("openThumb()", aniInterval);
		element.getElementsByTagName('A')[0].setAttribute("title","Απόκρυψη πληροφοριών");
	} else {
		thumbInt = setInterval("closeThumb()", aniInterval);
		element.getElementsByTagName('A')[0].setAttribute("title","Εμφάνιση πληροφοριών για το συγκεκριμένο βίντεο");
	}
}

// almost entirely borrowed from moo.fx: moofx.mad4milk.net
animate = function(element, oldHeight, newHeight) {
	var time  = (new Date).getTime();
	if(time >= duration+startTime) {
		now = newHeight;
		clearInterval(thumbInt);
		thumbInt = null;
		if(newHeight > 100) {
			element.style.height = "auto";
			return true;
		}
	} else {
		var tPos = (time - startTime) / duration;
		now = transition(tPos) * (newHeight-oldHeight) + oldHeight;
	}
	element.style.height = now+"px";
}

transition = function(pos){
	return ((-Math.cos(pos*Math.PI)/2) + 0.5);
	//this transition is from script.aculo.us (and I borrowed it from moo.fx.js)
}