var visiblePicture = null;
var pictureWidth = 0;
var pictureHeight = 0;
var indexPrev = 0;
var indexNext = 0;

function viewPictureIndex(index)
{
	self.scrollTo(0,0);
	
	var idx = index;
	
	if (idx < 0 || idx >= pictureFiles.length)
		idx = pictureFiles.length - 1;

	visiblePicture = true;
	
	var preview = document.getElementById('galleryViewer');
	var picture = document.getElementById('galleryPictureIndex');
	
	picture.setAttribute('src', galleryDir + pictureFiles[idx]);
	preview.style.visibility = 'visible';
	
	setPrevLastIndex(idx);
	setPrevLastVisibility(idx);
	backgroundCover(true);
}

function closePictureIndex()
{
	visiblePicture = false;
	
	var preview = document.getElementById('galleryViewer');
	var picture = document.getElementById('galleryPictureIndex');
	
	picture.setAttribute('src', '');
	preview.style.visibility = 'hidden';

	backgroundCover(false);

	var first = document.getElementById('galleryViewerFirstLink');
	var prev = document.getElementById('galleryViewerPrevLink');
	var next = document.getElementById('galleryViewerNextLink');
	var last = document.getElementById('galleryViewerLastLink');

	first.style.visibility = 'hidden';
	prev.style.visibility = 'hidden';
	next.style.visibility = 'hidden';
	last.style.visibility = 'hidden';
}

function setPrevLastVisibility(index)
{
	var first = document.getElementById('galleryViewerFirstLink');
	var prev = document.getElementById('galleryViewerPrevLink');
	var next = document.getElementById('galleryViewerNextLink');
	var last = document.getElementById('galleryViewerLastLink');

	if(index <= 0)
	{
		first.style.visibility = 'hidden';
		prev.style.visibility = 'hidden';
		next.style.visibility = 'visible';
		last.style.visibility = 'visible';
	}
	else if(index >= pictureFiles.length - 1)
	{
		first.style.visibility = 'visible';
		prev.style.visibility = 'visible';
		next.style.visibility = 'hidden';
		last.style.visibility = 'hidden';
	}
	else
	{
		first.style.visibility = 'visible';
		prev.style.visibility = 'visible';
		next.style.visibility = 'visible';
		last.style.visibility = 'visible';
	}
}

function setPrevLastIndex(index)
{
	indexPrev = index - 1;
	indexNext = index + 1;
	
	if (indexPrev < 0)
		indexPrev = 0;		
}

function viewPicture(p, width, height)
{
	visiblePicture = true;
	pictureWidth = width;
	pictureHeight = height;
	
	var picture = document.getElementById('galleryPicture');
	
	picture.setAttribute('src', p);
	picture.style.visibility = 'visible';
	
	backgroundCover(true);
	positionPicture();
}

function closePicture()
{
	visiblePicture = false;
	
	var picture = document.getElementById('galleryPicture');
	
	picture.setAttribute('src', '');
	picture.style.visibility = 'hidden';
	
	backgroundCover(false);
}

function positionPicture()
{
	var pos = document.getElementById('checkpoint');
	var pic = document.getElementById('galleryPicture');
	
	pic.style.top = '100px';
	pic.style.left = ((pos.offsetLeft - pictureWidth) / 2) + 'px';
}
	
function backgroundCover(b)
{
	var cover = document.getElementById('galleryCover');
	var pos = document.getElementById('checkpoint');
	
	if(b == true)
	{			
		cover.style.zIndex = '1000';
		//cover.style.height = pos.offsetTop + 'px';
		cover.style.height = '2000px';
		cover.style.width = pos.offsetLeft + 'px';
		cover.style.visibility = 'visible';
	}
	else
	{
		cover.style.zIndex = '0';
		cover.style.height = '0px';
		cover.style.width = '0px';
		cover.style.visibility = 'hidden';
	}
}

function windowResized()
{
    var cover = document.getElementById('galleryCover');
    var pos = document.getElementById('checkpoint');
    
    if(cover.style.visibility == 'visible')
    {
        //cover.style.height = pos.offsetTop + 'px';
        cover.style.height = '2000px';
		cover.style.width = pos.offsetLeft + 'px';
    }
    
	if(visiblePicture != null)
	{
		positionPicture();
	}
}