// IXF1.11 :: Image cross-fade 
// *****************************************************
// DOM scripting by brothercake -- http://www.brothercake.com/
//******************************************************
//global object
var ixf = { 'clock' : null, 'count' : 1 }
var TotalX = 0;
var TotalY = 0;
/*******************************************************


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

ixf.imgs = Array();

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

function positioning() {
	//keep new image in position with original image
	//in case text size changes mid transition or something
	TotalX = ixf.getRealPosition(ixf.obj, 'x') + 'px';
	TotalY = ixf.getRealPosition(ixf.obj, 'y') + 'px';
    ixf.newimg.style.left = TotalX;
    ixf.newimg.style.top = TotalY;
    ixf.borderimg.style.left = TotalX;
	ixf.borderimg.style.top = TotalY;
    ixf.textdiv.style.left = TotalX;
    ixf.textdiv.style.top = TotalY;
}

function cacheImages ()  {
	ixf.imgs = pictures;
	//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];
	}
        ixf.obj = arguments[0];

		//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 = ixf.obj.parentNode.appendChild((typeof document.createElementNS != 'undefined') ? document.createElementNS('http://www.w3.org/1999/xhtml', 'img') : document.createElement('img'));

		//set positioning classname
		ixf.newimg.className = 'idupe';

            
        ixf.borderimg = ixf.obj.parentNode.appendChild((typeof document.createElementNS != 'undefined') ? document.createElementNS('http://www.w3.org/1999/xhtml', 'div') : document.createElement('div'));
        ixf.borderimg.className = 'randpng';    
        
        ixf.textdiv = ixf.obj.parentNode.appendChild((typeof document.createElementNS != 'undefined') ? document.createElementNS('http://www.w3.org/1999/xhtml', 'div') : document.createElement('div'));
        ixf.textdiv.className = 'imgtext';    
        ixf.textdiv.innerHTML = ixf.obj.getAttribute('alt');
        positioning();
        positioning();  // nur so funzt es im IE8
        window.onresize = positioning;
}

/*****************************************************************************
  Drei Argumente: Img.src (nächstes in Darstellung)
                          Dauer, Alt-Text
*****************************************************************************/

//crossfade setup function
function crossfade() {
	counter++;
	quot = (counter%(pictures.length));
	
	//if the timer is not already going
	if(ixf.clock == null) {
		
		//copy the image src argument 
		ixf.src = arguments[0];
		
		//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[2] != 'undefined' && arguments[2] != '') {
			ixf.obj.alt = arguments[2];
		}
		
		//if any kind of opacity is supported
		if(ixf.type != 'none') {			
			//set src to new image src
			ixf.newimg.src = ixf.src

			//copy and convert fade duration argument 
			ixf.length = parseInt(arguments[1], 10) * 1000;
			
			//create fade resolution argument as 20 steps per transition
			ixf.resolution = parseInt(arguments[1], 10) * 20;
            
			ixf.textdiv.innerHTML = ixf.obj.alt;
            ixf.textdiv.style.visibility = 'hidden';

			//start the timer
			ixf.clock = setInterval('ixf.crossfade()', ixf.length/ixf.resolution);
		} else { //otherwise if opacity is not supported
			//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(ixf.count < 0) {
       
		//clear the timer
		clearInterval(ixf.clock);
		ixf.clock = null;
        ixf.obj.style.visibility = 'visible';
		
		//reset the counter
		ixf.count = 1;
        } else if(ixf.count < (1 / ixf.resolution)) {
		ixf.count = 0;
        ixf.obj.style.visibility = 'hidden';
		//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;
            ixf.textdiv.filters.alpha.opacity = (ixf.clock == null) ? 70 : (1 - ixf.count) * 70;
			break;
		case 'khtml' :
			ixf.obj.style.KhtmlOpacity = ixf.count;
			ixf.newimg.style.KhtmlOpacity = (1 - ixf.count);
			ixf.textdiv.style.KhtmlOpacity = (ixf.clock == null) ? 0.7 : 0.7 * (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);
			ixf.textdiv.style.MozOpacity = (ixf.clock == null) ? 0.7 : 0.7 * (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);
			ixf.textdiv.style.opacity = (ixf.clock == null) ? 0.7 : 0.7 * (1 - ixf.count);
	}
	
	//now that we've gone through one fade iteration 
	//we can show the image that's fading in
	if (ixf.clock != null) {
        ixf.newimg.style.visibility = 'visible';
        ixf.textdiv.style.visibility = 'visible';
    }

    positioning();
};