// 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 = []; /***************************************************************************** *****************************************************************************/ //cache the images ixf.imgsLen = ixf.imgs.length; ixf.cache = []; // MZ fadeable image function fadeableImage(img) { this.img = img; this.fadelevel = 0; //alert(img.src); } fadeableImage.prototype.setOpacity = function(o) { this.fadelevel = o; //alert(img.src + ':' + o); switch(ixf.type) { case 'ie' : this.img.filters.alpha.opacity = o * 100; break; case 'khtml' : this.img.style.KhtmlOpacity = o; break; case 'moz' : //restrict max opacity to prevent a visual popping effect in firefox this.img.style.MozOpacity = (o == 1 ? 0.9999999 : o); break; default : //restrict max opacity to prevent a visual popping effect in firefox this.img.style.opacity = (o == 1 ? 0.9999999 : o); } } fadeableImage.prototype.replaceSrc = function(src) { this.img.src = src; //this.setOpacity(this.fadelevel); // make the fadelevel current } fadeableImage.prototype.copyPosition = function(fa) { this.img.style.left = ixf.getRealPosition(fa.img, 'x') + 'px'; this.img.style.top = ixf.getRealPosition(fa.img, 'y') + 'px'; } fadeableImage.prototype.clone = function(fa, src) { //create a new image object and append it to body //detecting support for namespaced element creation, in case we're in the XML DOM var img = document.getElementsByTagName('body')[0].appendChild((typeof document.createElementNS != 'undefined') ? document.createElementNS('http://www.w3.org/1999/xhtml', 'img') : document.createElement('img')); //set positioning classname img.className = 'idupe'; img.src = src; //move it to superimpose original image var newfa = new fadeableImage(img); newfa.copyPosition(fa); return newfa; } fadeableImage.prototype.destroy = function() { this.img.parentNode.removeChild(this.img); } //crossfade setup function function crossfade() { // cancels the existing fade and starts over if(ixf.clock != null) { // if the fade is less than half over if (ixf.count > .5) { //alert('half'); //make the new image the same as the existing new one, opacity, etc. ixf.newimage.replaceSrc(arguments[1]); } else { var f = ixf.newimage.fadelevel; ixf.newimage.setOpacity(ixf.old.fadelevel); ixf.newimage.replaceSrc(arguments[1]); ixf.old.setOpacity(f); // ixf.old.replaceSrc(ixf.newimage.img.src); ixf.count = ixf.count + .5; } //ixf.count = 1-ixf.count; return; } if (1 == 1) //if the timer is not already going { //copy the image object ixf.obj = arguments[0]; ixf.old = new fadeableImage(ixf.obj); //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') { ixf.newimage = ixf.old.clone(ixf.old, ixf.src); //create a newimg based on the old ixf.newimg = ixf.newimage.img; //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 //MZ - has this been initialized? 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.old.replaceSrc(ixf.newimage.img.src); //ixf.obj.src = ixf.src; } //set new opacity value on both elements //using whatever method is supported //alert(ixf.old.fadelevel); ixf.old.setOpacity(ixf.count); ixf.newimage.setOpacity(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.newimage.copyPosition(ixf.old); //if the counter is at the top, which is just after the timer has finished if(ixf.count == 1) { //remove the duplicate image ixf.newimage.destroy(); if(typeof(fadeCompleted) !== 'undefined' && fadeCompleted !== null) { fadeCompleted(); //callback function } } }; //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; };