// IXF1.0 :: Image cross-fade 

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

// DOM scripting by brothercake -- http://www.brothercake.com/

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

//global object

var ixw = { 'clock' : null, 'count' : 1 }

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







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

 List the images that need to be cached

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



ixw.imgs = [

	'buttons/udm4-greenbutton88x31.gif',

	'buttons/udm4-whitebutton88x31.gif',

	'buttons/udm4-bluebutton88x31.gif',

	'buttons/udm4-redbutton88x31.gif',

	'buttons/udm4-purplebutton88x31.gif',

	'buttons/udm4-blackbutton88x31.gif',

	];



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

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







//cache the images

ixw.imgsLen = ixw.imgs.length;

ixw.cache = [];

for(var i=0; i<ixw.imgsLen; i++)

{

	ixw.cache[i] = new Image;

	ixw.cache[i].src = ixw.imgs[i];

}





//crosswipe setup function

function crosswipe()

{

	//if the timer is not already going

	if(ixw.clock == null)

	{

		//copy the image object 

		ixw.obj = arguments[0];

		

		//get its dimensions

		ixw.size = { 'w' : ixw.obj.width, 'h' : ixw.obj.height };

		

		//copy the image src argument 

		ixw.src = arguments[1];

		

		//change the image alt text if defined

		if(typeof arguments[4] != 'undefined' && arguments[4] != '')

		{

			ixw.obj.alt = arguments[4];

		}



		//if dynamic element creation is supported

		if(typeof document.createElementNS != 'undefined' || typeof document.createElement != 'undefined')

		{

			//create a new image object and append it to body

			//detecting support for namespaced element creation, in case we're in the XML DOM

			ixw.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

			ixw.newimg.className = 'idupe';



			//set src to new image src

			ixw.newimg.src = ixw.src



			//move it to superimpose original image

			ixw.newimg.style.left = ixw.getRealPosition(ixw.obj, 'x') + 'px';

			ixw.newimg.style.top = ixw.getRealPosition(ixw.obj, 'y') + 'px';



			//set it to be completely hidden with clip

			ixw.newimg.style.clip = 'rect(0, 0, 0, 0)';



			//show the image 

			ixw.newimg.style.visibility = 'visible';



			//copy and convert fade duration argument 

			ixw.length = parseInt(arguments[2], 10) * 1000;



			//create fade resolution argument as 20 steps per transition

			ixw.resolution = parseInt(arguments[2], 10) * 20;



			//copy slide direction argument

			ixw.dir = arguments[3];



			//start the timer

			ixw.clock = setInterval('ixw.crosswipe()', ixw.length/ixw.resolution);

		}

		

		//otherwise if dynamic element creation is not supported

		else

		{

			//just do the image swap

			ixw.obj.src = ixw.src;

		}

		

	}

};





//crosswipe timer function

ixw.crosswipe = function()

{

	//decrease the counter on a linear scale

	ixw.count -= (1 / ixw.resolution);

	

	//if the counter has reached the bottom

	if(ixw.count < (1 / ixw.resolution))

	{

		//clear the timer

		clearInterval(ixw.clock);

		ixw.clock = null;

		

		//reset the counter

		ixw.count = 1;

		

		//set the original image to the src of the new image

		ixw.obj.src = ixw.src;

	}

	

	//animate the clip of the new image

	//using the width and height properties we saved earlier

	ixw.newimg.style.clip = 'rect('

		+ ( (/bt|bltr|brtl/.test(ixw.dir)) ? (ixw.size.h * ixw.count) : (/che|cc/.test(ixw.dir)) ? ((ixw.size.h * ixw.count) / 2) : (0) )

		+ 'px, '

		+ ( (/lr|tlbr|bltr/.test(ixw.dir)) ? (ixw.size.w - (ixw.size.w * ixw.count)) : (/cve|cc/.test(ixw.dir)) ? (ixw.size.w - ((ixw.size.w * ixw.count) / 2)) : (ixw.size.w) )

		+ 'px, '

		+ ( (/tb|tlbr|trbl/.test(ixw.dir)) ? (ixw.size.h - (ixw.size.h * ixw.count)) : (/che|cc/.test(ixw.dir)) ? (ixw.size.h - ((ixw.size.h * ixw.count) / 2)) : (ixw.size.h) )

		+ 'px, '

		+ ( (/lr|tlbr|bltr/.test(ixw.dir)) ? (0) : (/tb|bt|che/.test(ixw.dir)) ? (0) : (/cve|cc/.test(ixw.dir)) ? ((ixw.size.w * ixw.count) / 2) : (ixw.size.w * ixw.count) ) 

		+ 'px)';

			

	//keep new image in position with original image

	//in case text size changes mid transition or something

	ixw.newimg.style.left = ixw.getRealPosition(ixw.obj, 'x') + 'px';

	ixw.newimg.style.top = ixw.getRealPosition(ixw.obj, 'y') + 'px';

	

	//if the counter is at the top, which is just after the timer has finished

	if(ixw.count == 1)

	{

		//remove the duplicate image

		ixw.newimg.parentNode.removeChild(ixw.newimg);

	}

};







//get real position method

ixw.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;

};