/*
        Lightbox JS: Fullsize Image Overlays
        by Lokesh Dhakar - http://www.huddletogether.com

        For more information on this script, visit:
        http://huddletogether.com/projects/lightbox/

        Licensed under the Creative Commons Attribution 2.5 License - http://creativecommons.org/licenses/by/2.5/
        (basically, do anything you want, just leave my name and link)

        Table of Contents
        -----------------
        Configuration

        Functions
        - getPageScroll()
        - getPageSize()
        - pause()
        - getKey()
        - listenKey()
        - showLightbox()
        - hideLightbox()
        - initLightbox()
        - addLoadEvent()

        Function Calls
        - addLoadEvent(initLightbox)

*/



//
// Configuration
//

// If you would like to use a custom loading image or close button reference them in the next two lines.
var loadingImage = 'images/img/loading.gif';
var closeButton = 'images/img/close.gif';





//
// getPageScroll()
// Returns array with x,y page scroll values.
// Core code from - quirksmode.org
//
function getPageScroll(){

        var yScroll;

        if (self.pageYOffset) {
                yScroll = self.pageYOffset;
        } else if (document.documentElement && document.documentElement.scrollTop){         // Explorer 6 Strict
                yScroll = document.documentElement.scrollTop;
        } else if (document.body) {// all other Explorers
                yScroll = document.body.scrollTop;
        }

        arrayPageScroll = new Array('',yScroll)
        return arrayPageScroll;
}



//
// getPageSize()
// Returns array with page width, height and window width, height
// Core code from - quirksmode.org
// Edit for Firefox by pHaez
//
function getPageSize(){

        var xScroll, yScroll;

        if (window.innerHeight && window.scrollMaxY) {
                xScroll = document.body.scrollWidth;
                yScroll = window.innerHeight + window.scrollMaxY;
        } else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
                xScroll = document.body.scrollWidth;
                yScroll = document.body.scrollHeight;
        } else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
                xScroll = document.body.offsetWidth;
                yScroll = document.body.offsetHeight;
        }

        var windowWidth, windowHeight;
        if (self.innerHeight) {        // all except Explorer
                windowWidth = self.innerWidth;
                windowHeight = self.innerHeight;
        } else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
                windowWidth = document.documentElement.clientWidth;
                windowHeight = document.documentElement.clientHeight;
        } else if (document.body) { // other Explorers
                windowWidth = document.body.clientWidth;
                windowHeight = document.body.clientHeight;
        }

        // for small pages with total height less then height of the viewport
        if(yScroll < windowHeight){
                pageHeight = windowHeight;
        } else {
                pageHeight = yScroll;
        }

        // for small pages with total width less then width of the viewport
        if(xScroll < windowWidth){
                pageWidth = windowWidth;
        } else {
                pageWidth = xScroll;
        }


        arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight)
        return arrayPageSize;
}


//
// pause(numberMillis)
// Pauses code execution for specified time. Uses busy code, not good.
// Code from http://www.faqts.com/knowledge_base/view.phtml/aid/1602
//
function pause(numberMillis) {
        var now = new Date();
        var exitTime = now.getTime() + numberMillis;
        while (true) {
                now = new Date();
                if (now.getTime() > exitTime)
                        return;
        }
}

//
// getKey(key)
// Gets keycode. If 'x' is pressed then it hides the lightbox.
//

function getKey(e){
        if (e == null) { // ie
                keycode = event.keyCode;
        } else { // mozilla
                keycode = e.which;
        }
        key = String.fromCharCode(keycode).toLowerCase();

        if(key == 'x'){ hideLightbox(); }
}


//
// listenKey()
//
function listenKey () {        document.onkeypress = getKey; }


//
// showLightbox()
// Preloads images. Pleaces new image in lightbox then centers and displays.
//
function showLightbox(objLink)
{
        // prep objects
        var objOverlay = document.getElementById('overlay');
        var objLightbox = document.getElementById('lightbox');
        var objCaption = document.getElementById('lightboxCaption');
        var objImage = document.getElementById('lightboxImage');
        var objLoadingImage = document.getElementById('loadingImage');
        var objLightboxDetails = document.getElementById('lightboxDetails');


        var arrayPageSize = getPageSize();
        var arrayPageScroll = getPageScroll();

        // center loadingImage if it exists
        if (objLoadingImage) {
                objLoadingImage.style.top = (arrayPageScroll[1] + ((arrayPageSize[3] - 35 - objLoadingImage.height) / 2) + 'px');
                objLoadingImage.style.left = (((arrayPageSize[0] - 20 - objLoadingImage.width) / 2) + 'px');
                objLoadingImage.style.display = 'block';
        }

        // set height of Overlay to take up whole page and show
        objOverlay.style.height = (arrayPageSize[1] + 'px');
        objOverlay.style.display = 'block';

        // preload image
        imgPreload = new Image();

        imgPreload.onload=function(){
                objImage.src = objLink.href;

                // center lightbox and make sure that the top and left values are not negative
                // and the image placed outside the viewport
                var lightboxTop = arrayPageScroll[1] + ((arrayPageSize[3] - 35 - imgPreload.height) / 2);
                var lightboxLeft = ((arrayPageSize[0] - 20 - imgPreload.width) / 2);

                objLightbox.style.top = (lightboxTop < 0) ? "0px" : lightboxTop + "px";
                objLightbox.style.left = (lightboxLeft < 0) ? "0px" : lightboxLeft + "px";


                objLightboxDetails.style.width = imgPreload.width + 'px';

                if(objLink.getAttribute('title')){
                        objCaption.style.display = 'block';
                        //objCaption.style.width = imgPreload.width + 'px';
                        objCaption.innerHTML = objLink.getAttribute('title');
                } else {
                        objCaption.style.display = 'none';
                }

                // A small pause between the image loading and displaying is required with IE,
                // this prevents the previous image displaying for a short burst causing flicker.
                if (navigator.appVersion.indexOf("MSIE")!=-1){
                        pause(250);
                }

                if (objLoadingImage) {        objLoadingImage.style.display = 'none'; }

                // Hide select boxes as they will 'peek' through the image in IE
                selects = document.getElementsByTagName("select");
        for (i = 0; i != selects.length; i++) {
                selects[i].style.visibility = "hidden";
        }


                objLightbox.style.display = 'block';

                // After image is loaded, update the overlay height as the new image might have
                // increased the overall page height.
                arrayPageSize = getPageSize();
                objOverlay.style.height = (arrayPageSize[1] + 'px');

                // Check for 'x' keypress
                listenKey();

                return false;
        }

        imgPreload.src = objLink.href;

}





//
// hideLightbox()
//
function hideLightbox()
{
        // get objects
        objOverlay = document.getElementById('overlay');
        objLightbox = document.getElementById('lightbox');

        // hide lightbox and overlay
        objOverlay.style.display = 'none';
        objLightbox.style.display = 'none';

        // make select boxes visible
        selects = document.getElementsByTagName("select");
    for (i = 0; i != selects.length; i++) {
                selects[i].style.visibility = "visible";
        }

        // disable keypress listener
        document.onkeypress = '';
}




//
// initLightbox()
// Function runs on window load, going through link tags looking for rel="lightbox".
// These links receive onclick events that enable the lightbox display for their targets.
// The function also inserts html markup at the top of the page which will be used as a
// container for the overlay pattern and the inline image.
//
function initLightbox()
{

        if (!document.getElementsByTagName){ return; }
        var anchors = document.getElementsByTagName("a");

        // loop through all anchor tags
        for (var i=0; i<anchors.length; i++){
                var anchor = anchors[i];

                if (anchor.getAttribute("href") && (anchor.getAttribute("rel") == "lightbox")){
                        anchor.onclick = function () {showLightbox(this); return false;}
                }
        }

        // the rest of this code inserts html at the top of the page that looks like this:
        //
        // <div id="overlay">
        //                <a href="#" onclick="hideLightbox(); return false;"><img id="loadingImage" /></a>
        //        </div>
        // <div id="lightbox">
        //                <a href="#" onclick="hideLightbox(); return false;" title="Click aufs Bild zum schliessen">
        //                        <img id="closeButton" />
        //                        <img id="lightboxImage" />
        //                </a>
        //                <div id="lightboxDetails">
        //                        <div id="lightboxCaption"></div>
        //                        <div id="keyboardMsg"></div>
        //                </div>
        // </div>

        var objBody = document.getElementsByTagName("body").item(0);

        // create overlay div and hardcode some functional styles (aesthetic styles are in CSS file)
        var objOverlay = document.createElement("div");
        objOverlay.setAttribute('id','overlay');
        objOverlay.onclick = function () {hideLightbox(); return false;}
        objOverlay.style.display = 'none';
        objOverlay.style.position = 'absolute';
        objOverlay.style.top = '0';
        objOverlay.style.left = '0';
        objOverlay.style.zIndex = '90';
         objOverlay.style.width = '100%';
        objBody.insertBefore(objOverlay, objBody.firstChild);

        var arrayPageSize = getPageSize();
        var arrayPageScroll = getPageScroll();

        // preload and create loader image
        var imgPreloader = new Image();

        // if loader image found, create link to hide lightbox and create loadingimage
        imgPreloader.onload=function(){

                var objLoadingImageLink = document.createElement("a");
                objLoadingImageLink.setAttribute('href','#');
                objLoadingImageLink.onclick = function () {hideLightbox(); return false;}
                objOverlay.appendChild(objLoadingImageLink);

                var objLoadingImage = document.createElement("img");
                objLoadingImage.src = loadingImage;
                objLoadingImage.setAttribute('id','loadingImage');
                objLoadingImage.style.position = 'absolute';
                objLoadingImage.style.zIndex = '150';
                objLoadingImageLink.appendChild(objLoadingImage);

                imgPreloader.onload=function(){};        //        clear onLoad, as IE will flip out w/animated gifs

                return false;
        }

        imgPreloader.src = loadingImage;

        // create lightbox div, same note about styles as above
        var objLightbox = document.createElement("div");
        objLightbox.setAttribute('id','lightbox');
        objLightbox.style.display = 'none';
        objLightbox.style.position = 'absolute';
        objLightbox.style.zIndex = '100';
        objBody.insertBefore(objLightbox, objOverlay.nextSibling);

        // create link
        var objLink = document.createElement("a");
        objLink.setAttribute('href','#');
        objLink.setAttribute('title','Click zum schliessen');
        objLink.onclick = function () {hideLightbox(); return false;}
        objLightbox.appendChild(objLink);

        // preload and create close button image
        var imgPreloadCloseButton = new Image();

        // if close button image found,
        imgPreloadCloseButton.onload=function(){

                var objCloseButton = document.createElement("img");
                objCloseButton.src = closeButton;
                objCloseButton.setAttribute('id','closeButton');
                objCloseButton.style.position = 'absolute';
                objCloseButton.style.zIndex = '200';
                objLink.appendChild(objCloseButton);

                return false;
        }

        imgPreloadCloseButton.src = closeButton;

        // create image
        var objImage = document.createElement("img");
        objImage.setAttribute('id','lightboxImage');
        objLink.appendChild(objImage);

        // create details div, a container for the caption and keyboard message
        var objLightboxDetails = document.createElement("div");
        objLightboxDetails.setAttribute('id','lightboxDetails');
        objLightbox.appendChild(objLightboxDetails);

        // create caption
        var objCaption = document.createElement("div");
        objCaption.setAttribute('id','lightboxCaption');
        objCaption.style.display = 'none';
        objLightboxDetails.appendChild(objCaption);

        // create keyboard message
        var objKeyboardMsg = document.createElement("div");
        objKeyboardMsg.setAttribute('id','keyboardMsg');
        objKeyboardMsg.innerHTML = '<a href="#" onclick="hideLightbox(); return false;"><kbd>[X]</kbd> zum schliessen</a>';
        objLightboxDetails.appendChild(objKeyboardMsg);


}




//
// addLoadEvent()
// Adds event to window.onload without overwriting currently assigned onload functions.
// Function found at Simon Willison's weblog - http://simon.incutio.com/
//
function addLoadEvent(func)
{
        var oldonload = window.onload;
        if (typeof window.onload != 'function'){
            window.onload = func;
        } else {
                window.onload = function(){
                oldonload();
                func();
                }
        }

}



addLoadEvent(initLightbox);        // run initLightbox onLoad