var album_idx=0;
var thumb_idx=0;
var last_thumb_idx=0;

var currpos=0;
var tomove=0;
var acceleration=1;
var max_speed=20;
var speed=0;
var dir=1;
var mooving=false;
var thumbs_seek=5;

function init_album()
{
	$('album_img_display').src=album_id+"_"+image_names[album_idx]+"_small.jpg";
	prepare_img_display();
	create_thumbnails();
	move_thumbnails(0);
}

function create_thumbnails()
{
	for( var i=0;i<image_names.length;++i)
	{
		var img=document.createElement("img");
		img.style.position="absolute";
		img.style.left=i*105+"px";
		img.style.top="0px";
		img.src=album_id+"_"+image_names[i]+"_thumb.jpg";
		img.id=album_id+"_"+image_names[i]+"_thumb"; 
		
		
		img.onclick=new Function("Show("+i+")");
		img.style.cursor="pointer";
		
		$('album_thumbs').appendChild(img);
	}
}

function move_thumbnails()
{
	if( album_idx==0 )
	{		
		$('album_g_arrow_left').style.visibility="hidden";
		$('album_g_arrow_left_inactive').style.visibility="visible";
	}
	else if( album_idx>=image_names.length-1)
	{		
		$('album_g_arrow_right').style.visibility="hidden";
		$('album_g_arrow_right_inactive').style.visibility="visible";		
	}	
	else
	{		
		$('album_g_arrow_left').style.visibility="visible";
		$('album_g_arrow_left_inactive').style.visibility="hidden";
		
		$('album_g_arrow_right').style.visibility="visible";
		$('album_g_arrow_right_inactive').style.visibility="hidden";
	}
	
	if( thumb_idx>=image_names.length-6 )
	{
		$('album_arrow_right').style.visibility="hidden";
		$('album_arrow_right_inactive').style.visibility="visible";
		
		$('album_arrow_left').style.visibility="visible";
		$('album_arrow_left_inactive').style.visibility="hidden";
	}
	else if( thumb_idx==0 )
	{
		$('album_arrow_left').style.visibility="hidden";
		$('album_arrow_left_inactive').style.visibility="visible";
		
		$('album_arrow_right').style.visibility="visible";
		$('album_arrow_right_inactive').style.visibility="hidden";	
	}
	else
	{
		$('album_arrow_left').style.visibility="visible";
		$('album_arrow_left_inactive').style.visibility="hidden";
		
		$('album_arrow_right').style.visibility="visible";
		$('album_arrow_right_inactive').style.visibility="hidden";		
	}
	
	
	if( thumb_idx<=image_names.length-6 )
	{
		var delta=last_thumb_idx-thumb_idx;
		
		if( Math.abs(delta) >20 )
		{
			last_thumb_idx=thumb_idx;
			
			currpos-=delta*105;
			for( var i=0;i<image_names.length;++i)
			{	
				$(album_id+"_"+image_names[i]+"_thumb").style.left=(-1*currpos+i*105)+"px";
			}
		}
		else if( delta!=0 )
		{
			last_thumb_idx=thumb_idx;
	
			tomove+=delta*105;
	
			if( mooving==false )
			{
				mooving=true;
				clear_thumbnails();
				move_thumbnails_iter();
			}
		}
	}
}

function album_next_image()
{
	++album_idx;
	thumb_idx=album_idx;
	$('album_img_display').src=album_id+"_"+image_names[album_idx]+"_small.jpg";
	prepare_img_display();
	
	move_thumbnails();
}

function album_previous_image()
{
	--album_idx;
	thumb_idx=album_idx;
	$('album_img_display').src=album_id+"_"+image_names[album_idx]+"_small.jpg";
	prepare_img_display();
	
	move_thumbnails();	
}

function album_next_slide()
{
	thumb_idx+=thumbs_seek;
	
	if( thumb_idx>image_names.length-6)
	{
		thumb_idx=image_names.length-6;
	}
	
	move_thumbnails();	
}

function album_previous_slide()
{
	thumb_idx-=thumbs_seek;
	
	if( thumb_idx<0 )
		thumb_idx=0;
	
	move_thumbnails();
}

function Show(idx)
{
	album_idx=idx;
	
	$('album_img_display').src=album_id+"_"+image_names[idx]+"_small.jpg";
	prepare_img_display();
	
	move_thumbnails();
}

function prepare_img_display()
{
	var img=$('album_img_display');
	
	img.onclick=new Function("album_popup(this, "+album_idx+")");
}

function album_popup(obj, idx)
{
	var img=$('album_img_display');
	
	img.id=album_id+"_"+image_names[album_idx];
	PopupZoomImg2(obj, image_widths[idx], image_heights[idx]);
	img.id="album_img_display";
}

function clear_thumbnails()
{
	var start=thumb_idx-25;
	
	if( start <0 ) start=0;
	
	for( var i=0;i<image_names.length;++i)
	{
		if( i<start || i>=thumb_idx+25)
		{
			if( $(album_id+"_"+image_names[i]+"_thumb").style.left!="2500px")
			{
				$(album_id+"_"+image_names[i]+"_thumb").style.left="2500px";
			}
		}
	}
}

function move_thumbnails_iter()
{
	var abs_tomove=Math.abs(tomove);
	if( tomove>0 )
		dir=-1;
	else
		dir=1;
	
	if( abs_tomove-max_speed/acceleration<=0)
	{
		speed-=acceleration;
	}
	else
		speed+=acceleration;
		
	if(speed>max_speed )
		speed=max_speed;
		
	currpos+=dir*speed;
	tomove+=dir*speed;
	
	if( tomove*dir>0)
	{
		move_thumbnails();
		speed=0;
		mooving=false;
		clear_thumbnails();
		return;
	}
	
	var start=thumb_idx-25;
	
	if( start <0 ) start=0;
	
	for( var i=start;i<image_names.length && i< thumb_idx+25;++i)
	{
		$(album_id+"_"+image_names[i]+"_thumb").style.left=(-1*currpos+i*105)+"px";
	}
	
	setTimeout("move_thumbnails_iter()",10);	
}