// 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 = [

	'images/donors/2.jpg',
	'images/donors/3.jpg',
	'images/donors/4.jpg',
	'images/donors/5.jpg'

	];



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

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







//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];

}


//setup for cycling images-- added by ajs
var imgs1 = new Array("images/donors/2.jpg","images/donors/3.jpg","images/donors/4.jpg","images/donors/5.jpg");

var alts1 = new Array("Doris and Thomas Montgomery, Founders of the Montgomery Scholarship Fund. Learn more.","Kenneth L. Fisher, Leading financial advisor and supporter of Redwood Forest Ecology.Learn more.","Su Grigsby, HSU Alumn and Star Athlete. Learn more.","Franklin B. Rohner, Hollywood lawyer, producer and generous alumn.Learn more.");

// added by CK to store the URI for each donor bio
var hrefs1 = new Array("donors/montgomerys.php","donors/fisher.php","donors/grigsby.php","donors/rohner.php");

var currentAd1 = 3;
var imgCt1 = 4;



//crossfade setup function

function crossfade()

{
	setTimeout("crossfade()",10 * 1000);
	//loop images-- added by ajs
	 currentAd1++;
  if (currentAd1 == imgCt1) 
  {
    currentAd1 = 0;
  }
		
		
		
	  
	//if the timer is not already going

	if(ixf.clock == null)

	{

		//copy the image object 

		ixf.obj = document.getElementById('donorphoto');

		

		//copy the image src argument 

		ixf.src = imgs1[currentAd1];

		

		//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 alts1[currentAd1] != 'undefined' && alts1[currentAd1] != '')

		{

			ixf.obj.alt = alts1[currentAd1];

		}

		

		//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.getElementById('Donor').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(3, 10) * 1000;

			

			//create fade resolution argument as 20 steps per transition

			ixf.resolution = parseInt(3, 10) * 20;

			

			//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);

		
		// Added by CK to change the href depending on the image showing.
		
		//copy the href argument 

		ixf.href = hrefs1[currentAd1];

			//added by CK -- gets the a tag with id "Donor"

			ixf.newa = document.getElementById('Donor');
			
			//resets href as defined above
			ixf.newa.href = ixf.href;

	}

};







//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;

};