// -------------------------------------------------------------------
// Image Thumbnail Viewer Script- By Dynamic Drive, available at: http://www.dynamicdrive.com
// Last updated: July 7th, 2008- Fixed enlarged image not showing in IE sometimes
// -------------------------------------------------------------------

var thumbnailviewer = {
    enableTitle: true, //Should "title" attribute of link be used as description?
    enableAnimation: true, //Enable fading animation?
    definefooter: '<div class="footerbar"></div>', //Define HTML for footer interface
    defineLoading: '<img src="loading.gif" /> Loading Image...', //Define HTML for "loading" div
    /////////////No need to edit beyond here/////////////////////////
    
    scrollbarwidth: 16,
    opacitystring: 'filter:progid:DXImageTransform.Microsoft.alpha(opacity=10); -moz-opacity: 0.1; opacity: 0.1',
    targetlinks: [], //Array to hold links with rel="thumbnail"
    createthumbBox: function(){
        //write out HTML for Image Thumbnail Viewer plus loading div
        document.write('<div id="thumbBox" onClick="thumbnailviewer.closeit()"><div id="thumbImage"></div>' + this.definefooter + '</div>')
        document.write('<div id="thumbLoading">' + this.defineLoading + '</div>')
        this.thumbBox = document.getElementById("thumbBox")
        this.thumbImage = document.getElementById("thumbImage") //Reference div that holds the shown image
        this.thumbLoading = document.getElementById("thumbLoading") //Reference "loading" div that will be shown while image is fetched
        this.standardbody = (document.compatMode == "CSS1Compat") ? document.documentElement : document.body //create reference to common "body" across doctypes
    },
    
    
    centerDiv: function(divobj){ //Centers a div element on the page
        var ie = document.all && !window.opera
        var dom = document.getElementById
        var scroll_top = (ie) ? this.standardbody.scrollTop : window.pageYOffset
        var scroll_left = (ie) ? this.standardbody.scrollLeft : window.pageXOffset
        var docwidth = (ie) ? this.standardbody.clientWidth : window.innerWidth - this.scrollbarwidth
        var docheight = (ie) ? this.standardbody.clientHeight : window.innerHeight
        var docheightcomplete = (this.standardbody.offsetHeight > this.standardbody.scrollHeight) ? this.standardbody.offsetHeight : this.standardbody.scrollHeight //Full scroll height of document
        var objwidth = divobj.offsetWidth //width of div element
        var objheight = divobj.offsetHeight //height of div element
        var topposition = (docheight > objheight) ? scroll_top + docheight / 2 - objheight / 2 + "px" : scroll_top + 10 + "px" //Vertical position of div element: Either centered, or if element height larger than viewpoint height, 10px from top of viewpoint
        divobj.style.left = docwidth / 2 - objwidth / 2 + "px" //Center div element horizontally
        divobj.style.top = Math.floor(parseInt(topposition)) + "px"
        divobj.style.visibility = "visible"
    },
    
    showthumbBox: function(){ //Show ThumbBox div
        thumbnailviewer.thumbLoading.style.visibility = "hidden" //Hide "loading" div
        this.centerDiv(this.thumbBox)
        if (this.enableAnimation) { //If fading animation enabled
            this.currentopacity = 0.1 //Starting opacity value
            this.opacitytimer = setInterval("thumbnailviewer.opacityanimation()", 20)
        }
    },
    
    
    loadimage: function(link){ //Load image function that gets attached to each link on the page with rel="thumbnail"
        if (this.thumbBox.style.visibility == "visible") //if thumbox is visible on the page already
            this.closeit() //Hide it first (not doing so causes triggers some positioning bug in Firefox
        var imageHTML = '<img src="' + link.getAttribute("href") + '" style="' + this.opacitystring + '" />' //Construct HTML for shown image
        if (this.enableTitle && link.getAttribute("title")) //Use title attr of the link as description?
            imageHTML += '<br />' + link.getAttribute("title")
        this.centerDiv(this.thumbLoading) //Center and display "loading" div while we set up the image to be shown
        this.thumbImage.innerHTML = imageHTML //Populate thumbImage div with shown image's HTML (while still hidden)
        this.featureImage = this.thumbImage.getElementsByTagName("img")[0] //Reference shown image itself
        if (this.featureImage.complete) 
            thumbnailviewer.showthumbBox()
        else {
            this.featureImage.onload = function(){ //When target image has completely loaded
                thumbnailviewer.showthumbBox() //Display "thumbbox" div to the world!
            }
        }
        if (document.all && !window.createPopup) //Target IE5.0 browsers only. Address IE image cache not firing onload bug: panoramio.com/blog/onload-event/
            this.featureImage.src = link.getAttribute("href")
        this.featureImage.onerror = function(){ //If an error has occurred while loading the image to show
            thumbnailviewer.thumbLoading.style.visibility = "hidden" //Hide "loading" div, game over
        }
    },
    
    setimgopacity: function(value){ //Sets the opacity of "thumbimage" div per the passed in value setting (0 to 1 and in between)
        var targetobject = this.featureImage
        if (targetobject.filters && targetobject.filters[0]) { //IE syntax
            if (typeof targetobject.filters[0].opacity == "number") //IE6
                targetobject.filters[0].opacity = value * 100
            else //IE 5.5
                 targetobject.style.filter = "alpha(opacity=" + value * 100 + ")"
        }
        else 
            if (typeof targetobject.style.MozOpacity != "undefined") //Old Mozilla syntax
                targetobject.style.MozOpacity = value
            else 
                if (typeof targetobject.style.opacity != "undefined") //Standard opacity syntax
                    targetobject.style.opacity = value
                else //Non of the above, stop opacity animation
                     this.stopanimation()
    },
    
    opacityanimation: function(){ //Gradually increase opacity function
        this.setimgopacity(this.currentopacity)
        this.currentopacity += 0.1
        if (this.currentopacity > 1) 
            this.stopanimation()
    },
    
    stopanimation: function(){
        if (typeof this.opacitytimer != "undefined") 
            clearInterval(this.opacitytimer)
    },
    
    
    closeit: function(){ //Close "thumbbox" div function
        this.stopanimation()
        this.thumbBox.style.visibility = "hidden"
        this.thumbImage.innerHTML = ""
        this.thumbBox.style.left = "-2000px"
        this.thumbBox.style.top = "-2000px"
    },
    
    cleanup: function(){ //Clean up routine on page unload
        this.thumbLoading = null
        if (this.featureImage) 
            this.featureImage.onload = null
        this.featureImage = null
        this.thumbImage = null
        for (var i = 0; i < this.targetlinks.length; i++) 
            this.targetlinks[i].onclick = null
        this.thumbBox = null
    },
    
    dotask: function(target, functionref, tasktype){ //assign a function to execute to an event handler (ie: onunload)
        var tasktype = (window.addEventListener) ? tasktype : "on" + tasktype
        if (target.addEventListener) 
            target.addEventListener(tasktype, functionref, false)
        else 
            if (target.attachEvent) 
                target.attachEvent(tasktype, functionref)
    },
    
    init: function(){ //Initialize thumbnail viewer script by scanning page and attaching appropriate function to links with rel="thumbnail"
        if (!this.enableAnimation) 
            this.opacitystring = ""
        var pagelinks = document.getElementsByTagName("a")
        for (var i = 0; i < pagelinks.length; i++) { //BEGIN FOR LOOP
            if (pagelinks[i].getAttribute("rel") && pagelinks[i].getAttribute("rel") == "thumbnail") { //Begin if statement
                pagelinks[i].onclick = function(){
                    thumbnailviewer.stopanimation() //Stop any currently running fade animation on "thumbbox" div before proceeding
                    thumbnailviewer.loadimage(this) //Load image
                    return false
                }
                this.targetlinks[this.targetlinks.length] = pagelinks[i] //store reference to target link
            } //end if statement
        } //END FOR LOOP
        //Reposition "thumbbox" div when page is resized
        this.dotask(window, function(){
            if (thumbnailviewer.thumbBox.style.visibility == "visible") 
                thumbnailviewer.centerDiv(thumbnailviewer.thumbBox)
        }, "resize")
        
        
    } //END init() function
}

thumbnailviewer.createthumbBox() //Output HTML for the image thumbnail viewer
thumbnailviewer.dotask(window, function(){
    thumbnailviewer.init()
}, "load") //Initialize script on page load
thumbnailviewer.dotask(window, function(){
    thumbnailviewer.cleanup()
}, "unload")