/*  imgFader, version 1.0
 *  (c) 2008 Malte Sieb (http://www.maltesieb.de)
 *
 *  imgFader is freely distributable under the terms of the GPL license.
 *  For details, see my web site: http://www.maltesieb.org/skripte
 */
var Fade=function(c,d){
	this.fDur=1;
	this.delay=5;
	this.imgs=new Array();
	this.mode='random';
	this.clear=true;
	for(var i in d)this[i]=d[i];
	if(this.fDur>this.delay)this.fDur=this.delay;
	this.ce=Math.round((Math.random()*this.imgs.length)-0.499);/*Erstes Bild zufällig wählen*/
	this.eo=1;
	this.po=0;
	this.fps=25;
	this.c=c;
	if(this.clear)this._g(this.c).innerHTML='';
	this._g(c).style.position='relative';
	for(i=0;i<this.imgs.length;i++){
		this._a(i,this.imgs[i]);
	}
	this.start();
}

Fade.prototype.start=function(){
	var p=this;
	this.stop();
	this.s=window.setInterval(function(){p._s()},this.delay*1000);
}

	Fade.prototype.stop=function(){
	window.clearInterval(this.s);
}

Fade.prototype._a=function(i,img){
	this._g(this.c).innerHTML+='<img src="'+img+'" id="img'+i+'" alt="" />'+"\n";
	this._g('img'+i).style.position='absolute';
	this._so(i,(i==this.ce?this.eo:(i==this.pe?this.po:0)));
}

Fade.prototype._u=function(n){
	this.imgs=n;this._g(this.c).innerHTML='';
	for(i=0;i<n.length;i++){
		this._a(i,this.imgs[i]);
	}
}

Fade.prototype._g=function(i){
	return document.getElementById(i);
}

Fade.prototype._d=function(n){
	for(i=0;i<this.imgs.length;i++){
		if(n==this.imgs[i])return i;
	}
	return false;
}

Fade.prototype._so=function(i,o){
	var e=this._g('img'+i);o=o>1?1:(o<0?0:o);
	e.style.opacity=o;
	e.style.filter="alpha(opacity="+(o*100)+")";
}

Fade.prototype._f=function(){
	if(this.eo>=1){
		window.clearInterval(this.f);
	}
	var d=1/(this.fps*this.fDur);
	this._so(this.pe,(this.po-=d));
	this._so(this.ce,(this.eo+=d));
}

Fade.prototype._s=function(ce){
	if(this.s){
		window.clearInterval(this.s);
		window.clearInterval(this.f);
	}
	for(i=0;i<this.imgs.length;i++){
		if(i!=this.ce&&i!=this.pe)this._so(i,0);
	}
	var p=this,r;
	if(this.imgs.length>0){
		this.pe=this.ce;
		if(ce||ce==0){
			this.ce=ce;
			this.fe=null;
		}else if(this.mode=='random'){
			do 
				r=Math.round((Math.random()*this.imgs.length)-0.499);
			while(r==this.ce);
			this.ce=r;
		}else{
			if(++this.ce>(this.imgs.length-1)){
				this.ce=0;
			}
		}
		this.eo=0;
		this.po=1;
		this.f=window.setInterval(function(){p._f();},Math.round(this.fDur*1000/this.fps));
	}
	this.start();
}

Fade.prototype.add=function(img,d){
	var p,n=new Array();
	p=this._d(img);
	if(!p||d.force){
		if(d.pos&&d.pos=='first')d.pos=1;
		if(d.pos&&d.pos<=this.imgs.length){
			d.pos--;
			for(i=0;i<this.imgs.length;i++){
				if(i<d.pos)n[i]=this.imgs[i];
				else if(i==d.pos){
					n[i]=img;
					n[(i+1)]=this.imgs[i];
				}else n[(i+1)]=this.imgs[i];
			}
			if(this.ce>=d.pos){this.ce++;}
			if(this.pe>=d.pos){this.pe++;}
			this._u(n);
			p=d.pos;
		}else{
			this.imgs[this.imgs.length]=img;
			p=this.imgs.length-1;
			this._a(p,img);
		}
	}
	if(d.mode&&d.mode=='immediate'){this._s(p);}
}
	
Fade.prototype.go=function(p){
	if(typeof p=='string'&&p.indexOf('+')>-1){
		p=parseInt(p.substr(1))+this.ce+1;
		if(p>this.imgs.length)p=p-this.imgs.length;
	}else if(typeof p=='string'&&p.indexOf('-')>-1){
		p=this.ce-parseInt(p.substr(1))+1;
		if(p<=0)p=p+this.imgs.length;
	}
	this._s(parseInt(p)-1);
}

Fade.prototype.preload=function(img){var i=new Image;i.src=img;};