// arguments:	image	id,	rotation speed,	path to	images (optional), 
// new (optional)	arguments: for transitions,	mouse	events and random	rotation 
function feature_Rotator(id, speed,	path,	bTrans,	bMouse,	bRand) {
	var	imgObj = document.getElementById(id);	
	if (!imgObj) { //	in case	name,	not	id attached	to image
		imgObj = document.images[id];
		if (!imgObj) return;
		imgObj.id	=	id;
	}
	this.id	=	id;	this.speed = speed ||	4500;	// default speed of	rotation
	this.path	=	path ||	"";	 this.bRand	=	bRand;
	this.ctr = 0;	this.timer = 0;	this.imgs	=	[];	
	this._setupLink(imgObj,	bMouse);
	this.bTrans	=	bTrans &&	typeof imgObj.filters	!= 'undefined';
	var	index	=	feature_Rotator.col.length;	feature_Rotator.col[index] = this;
	this.animString	=	"feature_Rotator.col[" + index + "]";
}

feature_Rotator.col	=	[];	// hold	instances
feature_Rotator.resumeDelay	=	400; //	onmouseout resume	rotation after delay

// mouse events	pause/resume
feature_Rotator.prototype._setupLink = function(imgObj,	bMouse)	{	
	if ( imgObj.parentNode &&	imgObj.parentNode.tagName.toLowerCase()	== 'a' ) {
		var	parentLink = this.parentLink = imgObj.parentNode;
		if (bMouse)	{
			feature_Event.add(parentLink,	'mouseover', feature_Rotator.pause);
			feature_Event.add(parentLink,	'mouseout',	feature_Rotator.resume);
		}
	}
}

// so	instance can be	retrieved	by id	(as	well as	by looping through col)
feature_Rotator.getInstanceById	=	function(id) {
	var	len	=	feature_Rotator.col.length,	obj;
	for	(var i=0;	i<len; i++)	{
		obj	=	feature_Rotator.col[i];
		if (obj.id &&	obj.id ==	id ) {
			return obj;
		}
	}
	return null;
}

feature_Rotator.prototype.on_rotate	=	function() {}

feature_Rotator.prototype.addImages	=	function() { //	preloads images
	var	img;
	for	(var i=0;	arguments[i];	i++) {
		img	=	new	Image();
		img.src	=	this.path	+	arguments[i];
		this.imgs[this.imgs.length]	=	img;
	}
}

feature_Rotator.prototype.rotate = function()	{
	clearTimeout(this.timer);	this.timer = null;
	var	imgObj = document.getElementById(this.id);
	if ( this.bRand	)	{
		this.setRandomCtr();
	}	else {
		if (this.ctr < this.imgs.length-1) this.ctr++;
		else this.ctr	=	0;
	}
	if ( this.bTrans ) {
		this.doImageTrans(imgObj);
	}	else {
		imgObj.src = this.imgs[this.ctr].src;
	}
	this.swapAlt(imgObj);	this.prepAction(); this.on_rotate();
	this.timer = setTimeout( this.animString + ".rotate()",	this.speed);	 
}

feature_Rotator.prototype.setRandomCtr = function()	{
	var	i	=	0, ctr;
	do { 
		ctr	=	Math.floor(	Math.random()	*	this.imgs.length );
		i++; 
	}	while	(	ctr	== this.ctr	&& i < 6 )// repeat	attempts to	get	new	image, if	necessary
	this.ctr = ctr;
}

feature_Rotator.prototype.doImageTrans = function(imgObj)	{
	imgObj.style.filter	=	'blendTrans(duration=1)';
	if (imgObj.filters.blendTrans) imgObj.filters.blendTrans.Apply();
	imgObj.src = this.imgs[this.ctr].src;
	imgObj.filters.blendTrans.Play();	
}

feature_Rotator.prototype.swapAlt	=	function(imgObj) {
	if ( !imgObj.setAttribute	)	return;
	if ( this.alt	&& this.alt[this.ctr]	)	{
		imgObj.setAttribute('alt', this.alt[this.ctr]);
	}
	if ( this.title	&& this.title[this.ctr]	)	{
		imgObj.setAttribute('title', this.title[this.ctr]);
	}
}

feature_Rotator.prototype.prepAction = function()	{
	if ( this.actions	&& this.parentLink &&	this.actions[this.ctr] ) {
		if ( typeof	this.actions[this.ctr] ==	'string' ) {
			this.parentLink.href = this.actions[this.ctr];
		}	else if	(	typeof this.actions[this.ctr]	== 'function'	)	{
			// to	execute	function when	linked image clicked 
			// passes	id used	to uniquely	identify instance	 
			// retrieve	it using the feature_Rotator.getInstanceById function	
			// so	any	property of	the	instance could be	obtained for use in	the	function 
			var	id = this.id;
			this.parentLink.href = "javascript:	void " + this.actions[this.ctr]	+	"('" + id	+	"')";
		}	
	}
}

feature_Rotator.prototype.showCaption	=	function() {
	if ( this.captions &&	this.captionId ) {
		var	el = document.getElementById(	this.captionId );
		if ( el	&& this.captions[this.ctr] ) {
			el.innerHTML = this.captions[this.ctr];
		}
	}
}

// Start rotation	for	all	instances	
feature_Rotator.start	=	function() {
	var	len	=	feature_Rotator.col.length,	obj;
	for	(var i=0;	i<len; i++)	{
		obj	=	feature_Rotator.col[i];
		if (obj	&& obj.id	)	{
			clearTimeout(	obj.timer	); obj.timer = null; 
			obj.timer	=	setTimeout(	obj.animString + ".rotate()",	obj.speed);
		}
	}
}

// Stop	rotation for all instances 
feature_Rotator.stop = function()	{
	var	len	=	feature_Rotator.col.length,	obj;
	for	(var i=0;	i<len; i++)	{
		obj	=	feature_Rotator.col[i];
		if (obj	)	{	clearTimeout(obj.timer); obj.timer = null; }
	}
}

// for stopping/starting (onmouseover/out)
feature_Rotator.pause	=	function(e)	{	
	e	=	feature_Event.DOMit(e);
	var	id = e.target.id;
	var	obj	=	feature_Rotator.getInstanceById(id);
	if ( obj ) { clearTimeout( obj.timer );	obj.timer	=	null;	}
}

feature_Rotator.resume = function(e) {
	e	=	feature_Event.DOMit(e);
	var	id = e.target.id;
	var	obj	=	feature_Rotator.getInstanceById(id);
	if ( obj &&	obj.id ) {
		obj.timer	=	setTimeout(	obj.animString + ".rotate()",	feature_Rotator.resumeDelay	);
	}
}

// calls constructor,	addImages, adds	actions, etc.
feature_Rotator.setup	=	function ()	{
	if (!document.getElementById)	return;
	var	i, j,	rObj,	r, imgAr,	len;
	for	(i=0;	arguments[i];	i++) {
		rObj = arguments[i];
		r	=	new	feature_Rotator(rObj.id, rObj.speed, rObj.path,	rObj.bTrans, rObj.bMouse,	rObj.bRand);
		try	{
			imgAr	=	rObj.images; len = imgAr.length;
			for	(j=0;	j<len; j++)	{	r.addImages( imgAr[j]	); }
			if(	rObj.num ) r.ctr = rObj.num; //	for	seq	after	random selection
			if ( rObj.actions	&& rObj.actions.length ==	len	)	{
				r.addProp('actions', rObj.actions);
			}
			if ( rObj.alt	&& rObj.alt.length ==	len	)	{
				r.addProp('alt', rObj.alt);
			}
			if ( rObj.title	&& rObj.title.length ==	len	)	{
				r.addProp('title', rObj.title);
			}
			if ( rObj.captions ) {
				r.addProp('captions',	rObj.captions);
				r.captionId	=	rObj.captionId;
				feature_Rotator.addRotateEvent(r,	function (id)	{	
					return function()	{	feature_Rotator.getInstanceById(id).showCaption(); }
				}(rObj.id) );	// see Crockford js	good parts pg	39
			}
		}	catch	(e)	{	
			//alert(e.message);	
		}
	}
	feature_Rotator.start();
}

// add to	on_rotate	for	specified	instance (r)
// see usage above for captions
feature_Rotator.addRotateEvent = function( r,	fp ) {
	var	old_on_rotate	=	r.on_rotate;
	r.on_rotate	=	function() { old_on_rotate();	fp();	}
}

// for adding	actions, alt,	title
feature_Rotator.prototype.addProp	=	function(prop, ar) {
	if ( !this[prop] ) {
		this[prop] = [];
	}
	var	len	=	ar.length; 
	for	(var i=0;	i	<	len; i++)	{
		this[prop][	this[prop].length	]	=	ar[i]; 
	}
}