<?

Header("content-type: application/x-javascript");


// image_path() -- returns path to image files
function image_path() {
   return ("../gallery/slides/");                             // image search path setting
}


// getimagefiles -- returns javascript array of image file names
function getimagefiles($dirname=".") {
   $pattern  = "/\b(\.jpg|\.jpeg|\.png|\.gif)\b/i";           // valid image extensions
   $files    = array();
   $curimage = 0;
   if($handle = opendir($dirname)) {
      while (false !== ($filename = readdir($handle))) {
         if (preg_match($pattern, $filename)) {               // if this file is a valid image
            $files[$curimage] = $filename;
            $curimage++;
         }
      }
   closedir($handle);
   }
   sort($files);
   for ($i=0; $i < count($files); $i++) {
      echo 'imagefiles['.$i.'] = "'. $files[$i] .'";';        // Output JavaScript array
   }
return;
}

echo 'var imagefiles = [];';                                  // define JavaScript array
echo 'var image_path = "'.image_path().'";';                  // define JavaScript value
getimagefiles(image_path())                                   // output JavaScript array elements

?>

var firstPass    = 1;                                         // initial state variable
var random       = 0;                                         // random slide selection?
var pointer      = 0;                                         // foreground image pointer
var FadeDuration = 1500;                                      // fade duration in millisecond
var image_count  = imagefiles.length;

var imageArray   = [];

for (var i=0; i < image_count; i++ ) {
   imageArray[i] = new imageItem(image_path+imagefiles[i]);
}


function imageItem(image_location) {
   this.image_item     = new Image();
   this.image_item.src = image_location;
}


function get_ImageItemLocation(imageObj) {
   return(imageObj.image_item.src);
}


function random_index(nmax) {
   return Math.floor(Math.min(Math.random()*(nmax + 1),nmax));
}


function getNextImage() {
   var current = pointer;
   var next    = current;
   if (random) {
      while (next == current) {
         next = random_index(image_count-1);
      }
   }
   else {
      next = (current+1) % image_count;
   }
   var next_image = get_ImageItemLocation(imageArray[next]);
   pointer = next;
   return(next_image);
}


function SetOpacity(object,opacityPct) {
   object.style.opacity      = opacityPct/100;                       // Safari 1.2, newer Firefox and Mozilla, CSS3
   object.style.MozOpacity   = opacityPct/100;                       // Older Mozilla and Firefox
   object.style.KhtmlOpacity = opacityPct/100;                       // Safari<1.2, Konqueror
   object.style.filter       = "alpha(opacity=" + opacityPct + ");"; // IE/Win
}


function ChangeOpacity(id,interval,tstart,ostart,ostop) {
   var element = document.getElementById(id);
   var tnow    = (new Date()).getTime();
   var opacity = ostart + (ostop - ostart) * (tnow - tstart) / interval;
   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+"',"+interval+","+tstart+","+ostart+","+ostop+")",10);
   }
}


function FadeInImage(foregroundID,backgroundID) {
   var newImage   = getNextImage();
   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+"',"+FadeDuration+","+startMS+",100,0)",10);
      }
   }
   else {
      foreground.src = newImage;
   }
}


function SlideShow(foregroundID,backgroundID,displaySecs) {
   if (firstPass) {
      firstPass = 0;
      setTimeout("SlideShow('"+foregroundID+"','"+backgroundID+"',"+displaySecs+")",3500);
   }
   else {
      FadeInImage(foregroundID,backgroundID);
      setTimeout("SlideShow('"+foregroundID+"','"+backgroundID+"',"+displaySecs+")",displaySecs*1000);
   }
}