<?php header("Content-Type: application/javascript; charset=utf-8");


function dir_list($path, $test)
{ if ( !($dir_handle=@opendir($path)) )    // opens dir (A)
  { trigger_error("Unable to open $path");
    return null;
  }
  $theFiles = array();
  while ($file = readdir($dir_handle))     // gets next file
  {  if ( $test($file) )                   // if passes test
     array_push($theFiles, "$file");       // puts on array
  }
  closedir($dir_handle);
  sort($theFiles);  reset($theFiles);      // sorts array
  return $theFiles;
}

function is_jpg($f)
{  return preg_match("/\.jpg$|\.JPG$/i", $f); }

$pics=dir_list("ctChina", "is_jpg");
echo 'var pic = [ "';
echo implode('", "', $pics);
echo "\" ];\n";
?>

var captions = new Array();
var pic_dir = "";
var slide = new Array();
var index = 0;        // current slide index

function loadImage(url)
{  if (document.images)
   {    rslt = new Image();
        rslt.src = url;
        return rslt;
   }
}

if ( document.images ) 
{  loadImage(pic_dir + "forward_s.png");
   loadImage(pic_dir + "backward_s.png");
   for(var i in pic) { slide.push(loadImage(pic_dir + pic[i])); }
}

function prevSlide()
{  if(--index < 0)
   { index = pic.length-1;
   }
   changeSlide();
}

function nextSlide()
{  if( ++index >= pic.length)
   { index = 0
   }
   changeSlide();
}

function changeSlide()
{  document.getElementById('display').src = slide[index].src;
   if (captions[pic[index]]== undefined)
   {   document.getElementById('caption').innerHTML = ""; 
   }
   else
   {   document.getElementById('caption').innerHTML = captions[pic[index]]; }
}

function xPosition(nd)
{   var x=0;
    while ( nd && nd.offsetParent )
    {  x += nd.offsetLeft;
       nd = nd.offsetParent;
    }
    return x;
}

function whichSide(e)
{  var img=document.getElementById('display');
   var x=xPosition(img), half=img.clientWidth/2;
   if ( e.clientX-x > half ) nextSlide()
   else prevSlide();
}

/////  for touch screen   /////
function initSwipe()
{ var image=document.getElementById('display');
  image.addEventListener("touchstart", startPosition, false);
  image.addEventListener("touchmove", moveHandler, false);
  image.addEventListener("touchend", endHandler, false);
}

var tx, dir;
function startPosition(e)   // touchstart position
{  var touch = e.touches[0];  
   tx=touch.pageX; 
}

function moveHandler(e)     //  touchmove
{  e.preventDefault();
   var touch = e.touches[0];  
   dir=tx-touch.pageX;
}

function endHandler(e)     //  touchleave 
{  if ( dir > 35 )  nextSlide();
   if ( dir < -35 ) prevSlide();
   dir=tx=0;
}