Slideshow sencillo en Javascript

Un slideshow es un tipo de presentación de imágenes que van a apareciendo una después de la otra, en este tutorial les voy a enseñar a crear uno muy sencillo utilizando Javascript, el terminado es muy bueno aunque se puede mejorar pero las bases son las que les voy a mostrar para que al final puedan configurarlo ustedes mismos

El archivo terminado lo puedes ver aquí, el archivo js que vas a necesitar para poder aplicar las transiciones se encuentra aquí.

CSS

<style type="text/css">

.flashclass{ /*sample CSS class added to image slideshow container*/
width: 200px; /*a width should be defined for transition to work*/
border: 5px solid orange;
padding: 5px;
}

.flashclass img{
border-width: 0;
}

</style>

Javascript

<script type="text/javascript" name="transitionshow.js">

/***********************************************
* Random Transitions Slideshow- by JavaScript Kit (www.javascriptkit.com)
* This notice must stay intact for usage
* Visit JavaScript Kit at http://www.javascriptkit.com/ for full source code
***********************************************/
//Random Transitions Slideshow- By JavaScript Kit (http://www.javascriptkit.com)
//Created: Nov 3rd, 2008

var global_transitions=[ //array of IE transition strings
    "progid:DXImageTransform.A.Barn()",
    "progid:DXImageTransform.Microsoft.Blinds()",
    "progid:DXImageTransform.Microsoft.CheckerBoard()",
    "progid:DXImageTransform.Microsoft.Fade()",
    "progid:DXImageTransform.Microsoft.GradientWipe()",
    "progid:DXImageTransform.Microsoft.Inset()",
    "progid:DXImageTransform.Microsoft.Iris()",
    "progid:DXImageTransform.Microsoft.Pixelate(maxSquare=15)",
    "progid:DXImageTransform.Microsoft.RadialWipe()",
    "progid:DXImageTransform.Microsoft.RandomBars()",
    "progid:DXImageTransform.Microsoft.RandomDissolve()",
    "progid:DXImageTransform.Microsoft.Slide()",
    "progid:DXImageTransform.Microsoft.Spiral()",
    "progid:DXImageTransform.Microsoft.Stretch()",
    "progid:DXImageTransform.Microsoft.Strips()",
    "progid:DXImageTransform.Microsoft.Wheel()",
    "progid:DXImageTransform.Microsoft.Zigzag()"
]

function flashyslideshow(setting){
    this.wrapperid=setting.wrapperid
    this.imagearray=setting.imagearray
    this.pause=setting.pause
    this.transduration=setting.transduration/1000 //convert from miliseconds to seconds unit to pass into el.filters.play()
    this.currentimg=0
    var preloadimages=[] //temp array to preload images
    for (var i=0; i<this.imagearray.length; i++){
        preloadimages[i]=new Image()
        preloadimages[i].src=this.imagearray[i][0]
    }
    document.write('<div id="'+this.wrapperid+'" class="'+setting.wrapperclass+'"><div id="'+this.wrapperid+'_inner" style="width:100%">'+this.getSlideHTML(this.currentimg)+'</div></div>')
    var effectindex=Math.floor(Math.random()*global_transitions.length) //randomly pick a transition to utilize
    var contentdiv=document.getElementById(this.wrapperid+"_inner")
    if (contentdiv.filters){ //if the filters[] collection is defined on element (only in IE)
        contentdiv.style.filter=global_transitions[effectindex] //define transition on element
        this.pause+=setting.transduration //add transition time to pause
    }
    this.filtersupport=(contentdiv.filters && contentdiv.filters.length>0)? true : false //test if element supports transitions and has one defined
    var slideshow=this
    flashyslideshow.addEvent(contentdiv, function(){slideshow.isMouseover=1}, "mouseover")
    flashyslideshow.addEvent(contentdiv, function(){slideshow.isMouseover=0}, "mouseout")
    setInterval(function(){slideshow.rotate()}, this.pause)
}

flashyslideshow.addEvent=function(target, functionref, tasktype){
    if (target.addEventListener)
        target.addEventListener(tasktype, functionref, false);
    else if (target.attachEvent)
        target.attachEvent('on'+tasktype, function(){return functionref.call(target, window.event)});
},

flashyslideshow.setopacity=function(el, degree){ //sets opacity of an element (FF and non IE browsers only)
    if (typeof el.style.opacity!="undefined")
        el.style.opacity=degree
    else
        el.style.MozOpacity=degree
    el.currentopacity=degree
},

flashyslideshow.prototype.getSlideHTML=function(index){
    var slideHTML=(this.imagearray[index][1])? '<a href="'+this.imagearray[index][1]+'" target="'+this.imagearray[index][2]+'">\n' : '' //hyperlink slide?
    slideHTML+='<img src="'+this.imagearray[index][0]+'" />'
    slideHTML+=(this.imagearray[index][1])? '</a><br />' : '<br />'
    slideHTML+=(this.imagearray[index][3])? this.imagearray[index][3] : '' //text description?
    return slideHTML //return HTML for the slide at the specified index
}

flashyslideshow.prototype.rotate=function(){
    var contentdiv=document.getElementById(this.wrapperid+"_inner")
    if (this.isMouseover){ //if mouse is over slideshow
        return
    }
    this.currentimg=(this.currentimg<this.imagearray.length-1)? this.currentimg+1 : 0
    if (this.filtersupport){
        contentdiv.filters[0].apply()
    }
    else{
        flashyslideshow.setopacity(contentdiv, 0)
    }
    contentdiv.innerHTML=this.getSlideHTML(this.currentimg)
    if (this.filtersupport){
        contentdiv.filters[0].play(this.transduration)
    }
    else{
        contentdiv.fadetimer=setInterval(function(){
            if (contentdiv.currentopacity<1)
                flashyslideshow.setopacity(contentdiv, contentdiv.currentopacity+0.1)
            else
                clearInterval(contentdiv.fadetimer)
        }, 50) //end setInterval
    }
}

</script>

HTML

<script type="text/javascript">

var flashyshow=new flashyslideshow({ //create instance of slideshow
    wrapperid: "myslideshow", //unique ID for this slideshow
    wrapperclass: "flashclass", //desired CSS class for this slideshow
    imagearray: [
        ["http://upload.wikimedia.org/wikipedia/commons/thumb/c/cc/Maceio_Alagoas_Brasil.PNG/180px-Maceio_Alagoas_Brasil.PNG", "http://en.wikipedia.org/wiki/Summer", "_new", "Such a nice Summer getaway."],
        ["http://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Windbuchencom.jpg/250px-Windbuchencom.jpg", "http://en.wikipedia.org/wiki/Winter", "", "Winter is nice, as long as there's snow right?"],
        [http://tbn3.google.com/images?q=tbn:RaCzed35eJ1SvM:http://i28.photobucket.com/albums/c250/HoChinhMi/TypicalDutchSpring__byjaaphart-Jaap.jpg, "", "", "Flowers spring back to life in Spring."],
        [http://tbn1.google.com/images?q=tbn:UcU1K0a02oP52M:http://www.autumn-pictures.com/new-jersey-autumn8.jpg, "", "", "Ah the cool breeze of autumn."]
    ],
    pause: 2000, //pause between content change (millisec)
    transduration: 1000 //duration of transition (affects only IE users)
})

</script>