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



	// ---------- initializing - variables ----------


	// the speed between the fades (in seconds)
	var intervalSeconds = 5;
	// the speed of the actual fade (in seconds)
	var fadeSeconds = 2;
	// all images - the sequence listed here will be maintained
	ixf.imgs =
	[
		"images2/slideshow8.gif",
		"images2/slideshow9.gif",
		"images2/slideshow2.gif",
		"images2/slideshow3.gif",
		"images2/slideshow4.gif",
		"images2/slideshow5.gif",
		"images2/slideshow6.gif",
		"images2/slideshow10.gif",
		"images2/slideshow1.gif"
	];
	// all quotes - the sequence listed here will be maintained (make sure the sequence accords with the images)
	// leave empty if you do not want to use quotes
	ixf.quotes =
	[
		"Andre Heuvelman",
		"Robert Pino",
		"Han van der Leur",
		"Olphaert den Otter",
		"Fred Bergmans",
		"Annemiek Veelenturf",
		"Danny Romeijn",
		"Riet Beks",
		"Ingrid van de Linde"
	];



// scrambling the arrays (both constrained to each other)
done = new Array();
now = new Date();
seed = now.getSeconds();
for (count = 0; count + 2 < ixf.imgs.length; count += 2)
{
	randomNumber1 = Math.round(Math.random(seed) * (ixf.imgs.length - 1));
	while (checkDone(randomNumber1))
	{
		randomNumber1 = Math.round(Math.random(seed) * (ixf.imgs.length - 1));
	}
	done.push(randomNumber1);

	randomNumber2 = Math.round(Math.random(seed) * (ixf.imgs.length - 1));
	while (checkDone(randomNumber2))
	{
		randomNumber2 = Math.round(Math.random(seed) * (ixf.imgs.length - 1));
	}
	done.push(randomNumber2);

	// images
	buffer = ixf.imgs[randomNumber1];
	ixf.imgs[randomNumber1] = ixf.imgs[randomNumber2];
	ixf.imgs[randomNumber2] = buffer;
	// texts
	if (ixf.quotes)
	{
		buffer = ixf.quotes[randomNumber1];
		ixf.quotes[randomNumber1] = ixf.quotes[randomNumber2];
		ixf.quotes[randomNumber2] = buffer;
	}
}
function checkDone(number)
{
	var exists = false;

	for (i = 0; i < done.length; i ++)
	{
		if (done[i] == number)
		{
			exists = true;
			break;
		}
	}

	return exists;
}

//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) * 1000;
			
			//create fade resolution argument as 20 steps per transition
			ixf.resolution = parseInt(arguments[2], 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);
	}
};



//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;
};


	/*-----------------------------------------------------------------------------------------------------------
	|
	|															-SAUL additions
	|
	-----------------------------------------------------------------------------------------------------------*/

	// sliding in intervals (original was only onClick)
	var counter = 1;
	function slideIt()
	{
		// define crossfade (image-object, 'new src', 'seconds'[, 'new alt text'])
		crossfade(document.getElementById('slideImage'), ixf.imgs[counter], fadeSeconds)

		// text sliding, optional
		if (ixf.quotes)
		{
			document.getElementById("slideQuote").innerHTML = ixf.quotes[counter];
		}

		// counter loop
		counter = (counter < ixf.imgs.length - 1) ? counter + 1 : 0;

		setTimeout("slideIt()", (intervalSeconds + fadeSeconds) * 1000);
	}

	function firstSlide(fade)
	{
		this.fade = fade;

		// if the image tag is loaded
		if (document.getElementById('slideImage'))
		{
			document.getElementById('slideImage').src = ixf.imgs[ixf.imgs.length - 1];
			if (ixf.quotes)
			{
				document.getElementById("slideQuote").innerHTML = ixf.quotes[ixf.imgs.length - 1];
			}

			// start fade or not?
			if (fade)
			{
				setTimeout("slideIt()", (intervalSeconds + fadeSeconds) * 1000);
			}
		}
		else
		{
			setTimeout("firstSlide(fade)", 100);
		}
	}