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

var loadingImage = 'img/loading.gif';
var closeButton = '';

function getPageScroll(){

  var yScroll;

  if (self.pageYOffset) {
    yScroll = self.pageYOffset;
  } else if (document.documentElement && document.documentElement.scrollTop){
    yScroll = document.documentElement.scrollTop;
  } else if (document.body) {
    yScroll = document.body.scrollTop;
  }

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

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){
    xScroll = document.body.scrollWidth;
    yScroll = document.body.scrollHeight;
  } else {
    xScroll = document.body.offsetWidth;
    yScroll = document.body.offsetHeight;
  }
  
  var windowWidth, windowHeight;
  if (self.innerHeight) {
    windowWidth = self.innerWidth;
    windowHeight = self.innerHeight;
  } else if (document.documentElement && document.documentElement.clientHeight) {
    windowWidth = document.documentElement.clientWidth;
    windowHeight = document.documentElement.clientHeight;
  } else if (document.body) {
    windowWidth = document.body.clientWidth;
    windowHeight = document.body.clientHeight;
  }  

  if(yScroll < windowHeight){
    pageHeight = windowHeight;
  } else { 
    pageHeight = yScroll;
  }

  if(xScroll < windowWidth){
    pageWidth = windowWidth;
  } else {
    pageWidth = xScroll;
  }


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

function pause(numberMillis) {
  var now = new Date();
  var exitTime = now.getTime() + numberMillis;
  while (true) {
    now = new Date();
    if (now.getTime() > exitTime)
      return;
  }
}

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

function showLightbox(objLink)
{

  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();

  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';
    objLoadingImage.style.padding = '0';
  }

  objOverlay.style.height = (arrayPageSize[1] + 'px');
  objOverlay.style.display = 'block';

  imgPreload = new Image();

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

    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.innerHTML = objLink.getAttribute('title');
    } else {
      objCaption.style.display = 'none';
    }

    if (navigator.appVersion.indexOf("MSIE")!=-1){
      pause(250);
    } 

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

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

    objLightbox.style.display = 'block';

    arrayPageSize = getPageSize();
    objOverlay.style.height = (arrayPageSize[1] + 'px');
    return false;
  }

  imgPreload.src = objLink.href;
  
}

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

  objOverlay.style.display = 'none';
  objLightbox.style.display = 'none';

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

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

  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;}
    }
  }

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

  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();

  var imgPreloader = new Image();

  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(){};

    return false;
  }

  imgPreloader.src = loadingImage;

  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);

  var objLink = document.createElement("a");
  objLink.setAttribute('href','#');
  objLink.setAttribute('title','zavřít');
  objLink.onclick = function () {hideLightbox(); return false;}
  objLightbox.appendChild(objLink);

  var imgPreloadCloseButton = new Image();

  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;

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

  var objLightboxDetails = document.createElement("div");
  objLightboxDetails.setAttribute('id','lightboxDetails');
  objLightbox.appendChild(objLightboxDetails);

  var objCaption = document.createElement("div");
  objCaption.setAttribute('id','lightboxCaption');
  objLightboxDetails.appendChild(objCaption);
}

function addLoadEvent(func)
{  
  var oldonload = window.onload;
  if (typeof window.onload != 'function'){
      window.onload = func;
  } else {
    window.onload = function(){
    oldonload();
    func();
    }
  }
}

addLoadEvent(initLightbox);