// IXF1.11 :: Image cross-fade 
// *****************************************************
// DOM scripting by brothercake -- http://www.brothercake.com/
//******************************************************
//global object
var ixf = { 'clock' : null, 'count' : 1 }
/*******************************************************



/*****************************************************************************
 List the images that need to be cached
*****************************************************************************/

ixf.imgs = [
	'buttons/udm4-whitebutton88x31.gif',
	'buttons/udm4-greenbutton88x31.gif',
	'buttons/udm4-purplebutton88x31.gif'
	];

/*****************************************************************************
*****************************************************************************/



//cache the images
ixf.imgsLen = ixf.imgs.length;
ixf.cache = [];
for(var i=0; i<ixf.imgsLen; i++)
{
	ixf.cache[i] = new Image;
	ixf.cache[i].src = ixf.imgs[i];
}


//crossfade setup function
function crossfade()
{
	//if the timer is not already going
	if(ixf.clock == null)
	{
		//copy the image object 
		ixf.obj = arguments[0];
		
		//copy the image src argument 
		ixf.src = arguments[1];
		
		//store the supported form of opacity
		if(typeof ixf.obj.style.opacity != 'undefined')
		{
			ixf.type = 'w3c';
		}
		else if(typeof ixf.obj.style.MozOpacity != 'undefined')
		{
			ixf.type = 'moz';
		}
		else if(typeof ixf.obj.style.KhtmlOpacity != 'undefined')
		{
			ixf.type = 'khtml';
		}
		else if(typeof ixf.obj.filters == 'object')
		{
			//weed out win/ie5.0 by testing the length of the filters collection (where filters is an object with no data)
			//then weed out mac/ie5 by testing first the existence of the alpha object (to prevent errors in win/ie5.0)
			//then the returned value type, which should be a number, but in mac/ie5 is an empty string
			ixf.type = (ixf.obj.filters.length > 0 && typeof ixf.obj.filters.alpha == 'object' && typeof ixf.obj.filters.alpha.opacity == 'number') ? 'ie' : 'none';
		}
		else
		{
			ixf.type = 'none';
		}
		
		//change the image alt text if defined
		if(typeof arguments[3] != 'undefined' && arguments[3] != '')
		{
			ixf.obj.alt = arguments[3];
		}
		
		//if any kind of opacity is supported
		if(ixf.type != 'none')
		{
			//create a new image object and append it to body
			//detecting support for namespaced element creation, in case we're in the XML DOM
			ixf.newimg = document.getElementsByTagName('body')[0].appendChild((typeof document.createElementNS != 'undefined') ? document.createElementNS('http://www.w3.org/1999/xhtml', 'img') : document.createElement('img'));

			//set positioning classname
			ixf.newimg.className = 'idupe';
			
			//set src to new image src
			ixf.newimg.src = ixf.src

			//move it to superimpose original image
			ixf.newimg.style.left = ixf.getRealPosition(ixf.obj, 'x') + 'px';
			ixf.newimg.style.top = ixf.getRealPosition(ixf.obj, 'y') + 'px';
			
			//copy and convert fade duration argument 
			ixf.length = parseInt(arguments[2], 10) * 500;
			
			//create fade resolution argument as 20 steps per transition
			ixf.resolution = parseInt(arguments[2], 10) * 15;
			
			//start the timer
			ixf.clock = setInterval('ixf.crossfade()', ixf.length/ixf.resolution);
		}
		
		//otherwise if opacity is not supported
		else
		{
			//just do the image swap
			ixf.obj.src = ixf.src;
		}
		
	}
};


//crossfade timer function
ixf.crossfade = function()
{
	//decrease the counter on a linear scale
	ixf.count -= (1 / ixf.resolution);
	
	//if the counter has reached the bottom
	if(ixf.count < (1 / ixf.resolution))
	{
		//clear the timer
		clearInterval(ixf.clock);

		ixf.clock = null;
		
		//reset the counter
		ixf.count = 1;
		
		//set the original image to the src of the new image
		ixf.obj.src = ixf.src;
	}
	
	//set new opacity value on both elements
	//using whatever method is supported
	switch(ixf.type)
	{
		case 'ie' :
			ixf.obj.filters.alpha.opacity = ixf.count * 100;
			ixf.newimg.filters.alpha.opacity = (1 - ixf.count) * 100;
			break;
			
		case 'khtml' :
			ixf.obj.style.KhtmlOpacity = ixf.count;
			ixf.newimg.style.KhtmlOpacity = (1 - ixf.count);
			break;
			
		case 'moz' : 
			//restrict max opacity to prevent a visual popping effect in firefox
			ixf.obj.style.MozOpacity = (ixf.count == 1 ? 0.9999999 : ixf.count);
			ixf.newimg.style.MozOpacity = (1 - ixf.count);
			break;
			
		default : 
			//restrict max opacity to prevent a visual popping effect in firefox
			ixf.obj.style.opacity = (ixf.count == 1 ? 0.9999999 : ixf.count);
			ixf.newimg.style.opacity = (1 - ixf.count);
	}
	
	//now that we've gone through one fade iteration 
	//we can show the image that's fading in
	ixf.newimg.style.visibility = 'visible';
	
	//keep new image in position with original image
	//in case text size changes mid transition or something
	ixf.newimg.style.left = ixf.getRealPosition(ixf.obj, 'x') + 'px';
	ixf.newimg.style.top = ixf.getRealPosition(ixf.obj, 'y') + 'px';
	
	//if the counter is at the top, which is just after the timer has finished
	if(ixf.count == 1)
	{
		//remove the duplicate image
		ixf.newimg.parentNode.removeChild(ixf.newimg);
	}
};



//get real position method
ixf.getRealPosition = function()
{
	this.pos = (arguments[1] == 'x') ? arguments[0].offsetLeft : arguments[0].offsetTop;
	this.tmp = arguments[0].offsetParent;
	while(this.tmp != null)
	{
		this.pos += (arguments[1] == 'x') ? this.tmp.offsetLeft : this.tmp.offsetTop;
		this.tmp = this.tmp.offsetParent;
	}
	
	return this.pos;
};

var spinner_timer_repeater = null;
var spinner_current_item = null;
if (typeof spinner_speed == "undefined") var spinner_speed = 2500;


// Common functions 
function cachedImage(in_src) {
	var out_img = new Image;
	out_img.src = in_src
	return out_img;
}


//   ================ START SPINNER ===========================================  
function spinner_initialize(spinner_data) {
	var spinner_list = document.getElementById('spinner_list');
	var spinner_list_divs = null;
	var spinner_link = document.getElementById('spinner_image').getElementsByTagName('a')[0];
	var spinner_image = document.getElementById('spinner_image').getElementsByTagName('img')[0];
	var spinner_synopsis = document.getElementById('spinner_synopsis');
	
	// Size up left-hand menu 
	if (spinner_data.length > 10) spinner_list.className = "space1";
	if (spinner_data.length > 15) spinner_list.className = "space2";
	
	// Populate left-hand menu 
	spinner_list.innerHTML = "";
	for (var i = 0; i < spinner_data.length; i++) {
		if (typeof spinner_data[i].title == 'string') {
			spinner_list.innerHTML = spinner_list.innerHTML
				+ "<div id=\"spinner_list_"
				+ i
				+ "\"><a href=\"#\">"
				+ spinner_data[i].title
				+ "</a>"
				;
		}
	}
	
	// Wire up left-hand menu 
	spinner_list_divs = spinner_list.getElementsByTagName('div');
	for (var i = 0; i < spinner_list_divs.length; i++) {
		spinner_list_divs[i].getElementsByTagName('a')[0].href = "javascript:spinner_swap("
			+ spinner_list_divs[i].id.split("_")[2]
			+ ")"
			;
	}
	
	// Swap in first item 
	spinner_swap(0);
	
	// Start the timer 
	spinner_timer_repeater = setTimeout("spinner_spin();", spinner_speed + 1000);
}



//   ================ SWAP HANDLER ===========================================  
function spinner_swap(id) {
	var spinner_list_divs = document.getElementById('spinner_list').getElementsByTagName('div');
	var spinner_link = document.getElementById('spinner_image').getElementsByTagName('a')[0];
	var spinner_image = document.getElementById('spinner_image').getElementsByTagName('img')[0];
	var spinner_synopsis = document.getElementById('spinner_synopsis');
	
	// grey the selected item 
	for (var i = 0; i < spinner_list_divs.length; i++) {
		if (spinner_list_divs[i].id == 'spinner_list_'+id) spinner_list_divs[i].className = 'selected';
		else spinner_list_divs[i].className = '';
	}
	
	// change the link, image, synopsis 
	if (spinner_image.src.indexOf("trans.gif") >= 0) spinner_image.src = spinner_data[id].img.src
	else if(navigator.userAgent.indexOf("Firefox")!=-1) crossfade(spinner_image, spinner_data[id].img.src, '1', '');
	else spinner_image.src = spinner_data[id].img.src;
	spinner_link.href = spinner_data[id].href;
	spinner_synopsis.innerHTML = spinner_data[id].synop;
	
	spinner_current_item = id;
}



//   ================ SPIN HANDLER ===========================================  
var pause_spin = 0;
function spinner_spin() {
	var next_item = spinner_current_item + 1;
	if (pause_spin == 0) {
		if (typeof spinner_data[next_item].title == 'string') {
			spinner_swap(next_item);
		} else {
			spinner_swap(0);
		}
	}
	spinner_timer_repeater = setTimeout("spinner_spin();", spinner_speed);
}



// pause on hover 
var spinner_table = document.getElementById("spinner");
spinner_table.onmouseover = function(e) { pause_spin = 1; };
spinner_table.onmouseout = function(e) { pause_spin = 0; };