// $Id: slideshow.js,v 1.1 2006/04/19 19:42:32 timcn Exp $

if(isJsEnabled() && typeof slideshow != 'undefined') {
  addLoadEvent(initSlideshow);
}

function initSlideshow() {
  var p = $('slideshow-previous'), n = $('slideshow-next');
  if(p) p.onclick = function() { slideshowPrevious(); return false; };
  if(n) n.onclick = function() { slideshowNext(); return false; };
  slideshowPreload(0);
}

function slideshowPreload(i) {
  var n = slideshow[++i];
  if(n) {
    n.image = new Image();
    n.image.src = n.src;
    n.image.onload = function() { slideshowPreload(i); };
  }
}

function slideshowPrevious() {
  if(!(slideshow[--slideshow.current])) slideshow.current = slideshow.total;
  slideshowUpdate();
}

function slideshowNext() {
  if(!(slideshow[++slideshow.current])) slideshow.current = 1;
  slideshowUpdate();
}

function slideshowUpdate() {
  var o = slideshow[slideshow.current], i = $('slideshow-image'), c = $('slideshow-current'),
    d = $('slideshow-desc'), t = $('slideshow-title');

  if(i && o.src) i.src = o.src;
  if(d && o.desc) d.innerHTML = o.desc;
  if(t && o.title) t.innerHTML = o.title;
  if(c) c.innerHTML = slideshow.current;
  //document.location.hash = slideshow.current;
}