/*
AnimatedPNG - A Javascript library for animated PNG images 
Copyright (C) 2007-2008 Steve Jones (steve@squaregoldfish.co.uk)
Version 1.01
Web: http://www.squaregoldfish.co.uk/software/animatedpng
Email: animatedpng@squaregoldfish.co.uk

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details:
http://www.gnu.org/licenses/gpl.txt
*/

animatedPNGs = new Array();

function AnimatedPNG(imageName, lengthUnit, firstImage, imageCount, delay, vertical)
{
	this.imageWidth = lengthUnit;
	this.animName=imageName;
	//this.images=new Array();
	this.delays=new Array();
	this.padCount=0;
	this.firstImageNumber=0;
	this.lastImageNumber=imageCount-1;
	this.currentImage=0;
	this.repeat=true;
	this.animationRunning=false;
	this.animationDrawn=false;
	this.draw=function(delayStart)
	{
		var html=new Array();
		html[html.length]='<div id="'+this.animName+'" ';
		if (this.altText) html[html.length]=' alt="'+this.altText+'"';
		if (this.titleText) html[html.length]=' title="'+this.titleText+'"';
		html[html.length]='></div>';
		document.write(html.join(''));
		document.getElementById(this.animName).style.backgroundImage='url(\''+firstImage+'\')'; //document.getElementById(this.animName).src=this.images[this.firstImageNumber].src;
		if (!delayStart)
		{
			setTimeout('animatedPNGs[\''+this.animName+'\'].drawFrame()',this.delays[this.firstImageNumber]);
			this.animationRunning=true;
		}
		this.drawn=true;
	}
	this.setFrameDelay=function(frame,delay)
	{
		this.delays[frame]=delay;
	}
	this.setRepeat=function(repeat)
	{
		this.repeat=repeat;
		if (repeat&&!this.animationRunning)
			this.startAnimation();
	}
	this.startAnimation=function()
	{
		if(!this.animationRunning)
		{
			this.animationRunning=true;
			this.drawFrame();
		}
		document.getElementById(this.animName).style.display = 'block';
	}
	this.stopAnimation=function()
	{
		this.animationRunning=false;
		document.getElementById(this.animName).style.display = 'none';
	}
	this.drawFrame=function()
	{
		var drawImage=true;
		this.currentImage++;
		if (this.currentImage>this.lastImageNumber)
		{
			if (this.repeat)
				this.currentImage=this.firstImageNumber;
			else
			{
				drawImage=false;
				this.animationRunning=false;
			}
		}
		if (drawImage)
		{
			if (vertical)
				document.getElementById(this.animName).style.backgroundPosition='0 -'+this.currentImage*this.imageWidth+'px';
			else
				document.getElementById(this.animName).style.backgroundPosition='-'+this.currentImage*this.imageWidth+'px 0'; //document.getElementById(this.animName).src=this.images[this.currentImage].src;
			if (this.delays[this.currentImage]) delay=this.delays[this.currentImage];
			if (this.animationRunning) setTimeout('animatedPNGs[\''+this.animName+'\'].drawFrame()',delay);
		}
	}
	/*
	var head=null;
	var numbers='';
	var suffix=firstImage.substring(firstImage.length-4,firstImage.length);
	if (suffix.search(/\.png/i)!=0&&suffix.search(/\.jpg/i)!=0)
		throw'Invalid suffix for first image in animated PNG '+imageName+' - must be .png or .jpg';
	var finishedNumbers=false;
	var curIndex=firstImage.length-5;
	for (;curIndex>=0&&!finishedNumbers;curIndex--)
	{
		if (/[0-9]/.test(firstImage.charAt(curIndex)))
		{
			numbers=firstImage.charAt(curIndex)+numbers;
			if(firstImage.charAt(curIndex)=='0')
			this.padCount++;
		}
		else
			finishedNumbers=true;
	}
	numbers=parseInt(numbers);
	this.firstImageNumber=numbers;
	this.currentImage=numbers;
	head=firstImage.substring(0,curIndex+2);
	*/
	for (var i=0;i<imageCount;i++)//for (var i=numbers;i<imageCount+numbers;i++)
	{
		/*this.images[i]=new Image;
		this.images[i].src=head+pad(i,this.padCount)+suffix;
		this.lastImageNumber=i;*/
		this.delays[i]=delay;
	}
	animatedPNGs[imageName]=this;
}

function pad(number,padCount)
{
	var result=''+number;
	while (result.length<padCount+1)
		result='0'+result;
	return result;
}