// Browser Slide-Show script. With image cross fade effect for those browsers
// that support it.
// Script copyright (C) 2004-2008 www.cryer.co.uk.
// Script is free to use provided this copyright header is included.
var FadeDurationMS=3000;
function SetOpacity(object,opacityPct){
  // IE.
  object.style.filter = 'alpha(opacity=' + opacityPct + ')';
  // Old mozilla and firefox
  object.style.MozOpacity = opacityPct/100;
  // Everything else.
  object.style.opacity = opacityPct/100;
}

function ChangeOpacity(id,msDuration,msStart,fromO,toO){
  var element=document.getElementById(id);
  var msNow = (new Date()).getTime();
  var opacity = fromO + (toO - fromO) * (msNow - msStart) / msDuration;
  if (opacity>=100) {
    SetOpacity(element,100);
    element.timer = undefined;
  } else if (opacity<=0) {
    SetOpacity(element,0);
    element.timer = undefined;
  } else {
    SetOpacity(element,opacity);
    element.timer = window.setTimeout("ChangeOpacity('" + id + "'," + msDuration + "," + msStart + "," + fromO + "," + toO + ")",10);
  }
}

function FadeInImage(foregroundID,newImage,backgroundID){
  var foreground=document.getElementById(foregroundID);
  if (foreground.timer) window.clearTimeout(foreground.timer);
  if (backgroundID)  {
    var background=document.getElementById(backgroundID);
    if (background) {
      if (background.src) {
        foreground.src = background.src; 
        SetOpacity(foreground,100);
      }
      background.src = newImage;
      background.style.backgroundImage = 'url(' + newImage + ')';
      background.style.backgroundRepeat = 'no-repeat';
      var startMS = (new Date()).getTime();
      foreground.timer = window.setTimeout("ChangeOpacity('" + foregroundID + "'," + FadeDurationMS + "," + startMS + ",100,0)",10);
    }
  } else {
    foreground.src = newImage;
  }
}
var slideCache = new Array();

function RunSlideShow(pictureID,backgroundID,imageFiles,displaySecs){
  // Check if we're running on a small screen
  if(windowSize()[0] < 400) return;
  var imageSeparator = imageFiles.indexOf(";");
  var nextImage = imageFiles.substring(0,imageSeparator);
  FadeInImage(pictureID,nextImage,backgroundID);
  var futureImages = imageFiles.substring(imageSeparator+1,imageFiles.length)+ ';' + nextImage;
  setTimeout("RunSlideShow('"+pictureID+"','"+backgroundID+"','"+futureImages+"',"+displaySecs+")",displaySecs*1000);
  // Cache the next image to improve performance.
  imageSeparator = futureImages.indexOf(";");
  nextImage = futureImages.substring(0,imageSeparator);
  if (slideCache[nextImage] == null)
  {
    slideCache[nextImage] = new Image;
    slideCache[nextImage].src = nextImage;
  }
}

function windowSize() {
  var myWidth = 0, myHeight = 0;
  if( typeof( window.innerWidth ) == 'number' ) {
    //Non-IE
    myWidth = window.innerWidth;
    myHeight = window.innerHeight;
  } else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
    //IE 6+ in 'standards compliant mode'
    myWidth = document.documentElement.clientWidth;
    myHeight = document.documentElement.clientHeight;
  } else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
    //IE 4 compatible
    myWidth = document.body.clientWidth;
    myHeight = document.body.clientHeight;
  }
  return [ myWidth, myHeight ];
}

