// slide objct  - all the information for a single slide
// slideshow object- consists of all slide objects and runs the slideshow

//==================================================
// slide object
//==================================================
function slide(src,link,text,target,attr) {
  this.src = src;
  this.link = link;
  this.text = text;
  this.target = target;
  this.attr = attr;
  if (document.images) {
    this.image = new Image();
  }
  this.loaded = false;
  this.load = function() {
    if (!document.images) { return; }
    if (!this.loaded) {
      this.image.src = this.src;
      this.loaded = true;
    }
  }

  //--------------------------------------------------
  this.hotlink = function() {
    var mywindow;
    if (!this.link) return;
    if (this.target) {
      if (this.attr) {
        mywindow = window.open(this.link, this.target, this.attr);
  
      } else {
        mywindow = window.open(this.link, this.target);
      }
      if (mywindow && mywindow.focus) mywindow.focus();
    } else {
      location.href = this.link;
    }
  }
}

//==================================================
// slideshow object
//==================================================
function slideshow( slideshowname ) {
  // Constructor function for the slideshow object  ss = new slideshow("ss");

  this.name = slideshowname;
  this.repeat = true;
  this.prefetch = -1;
  this.image;
  this.textid;
  this.textarea;
  this.timeout = 3000;

  this.slides = new Array();
  this.current = 0;
  this.timeoutid = 0;

  this.add_slide = function(slide) {
	  var i = this.slides.length;
  
    if (this.prefetch == -1) {
      slide.load();
    }

    this.slides[i] = slide;
  }


  //--------------------------------------------------
  this.update = function() {
    if (! this.valid_image()) { return; }
    if (typeof this.pre_update_hook == 'function') {
      this.pre_update_hook();
    }
    var slide = this.slides[ this.current ];
    var dofilter = false;
    if (this.image &&
        typeof this.image.filters != 'undefined' &&
        typeof this.image.filters[0] != 'undefined') {

      dofilter = true;
    }
    slide.load();

    if (dofilter) {

      if (slide.filter &&
          this.image.style &&
          this.image.style.filter) {

        this.image.style.filter = slide.filter;

      }
      this.image.filters[0].Apply();
    }

    this.image.src = slide.image.src;

    if (dofilter) {
      this.image.filters[0].Play();
    }


    if (this.prefetch > 0) {

      var next, prev, count;
      next = this.current;
      prev = this.current;
      count = 0;
      do {

        if (++next >= this.slides.length) next = 0;
        if (--prev < 0) prev = this.slides.length - 1;

        this.slides[next].load();
        this.slides[prev].load();

      } while (++count < this.prefetch);
    }
  }

  //--------------------------------------------------
  this.next = function() {
    if (this.current < this.slides.length - 1) {
      this.current++;
    } else if (this.repeat) {
      this.current = 0;
    }

    this.update();
  }

  //--------------------------------------------------
  this.previous = function() {

    if (this.current > 0) {
      this.current--;
    } else if (this.repeat) {
      this.current = this.slides.length - 1;
    }
  
    this.update();
  }



  //--------------------------------------------------
  this.hotlink = function() {
    this.slides[ this.current ].hotlink();
  }


  //--------------------------------------------------
  this.loop = function() {
    if (this.current < this.slides.length - 1) {
      next_slide = this.slides[this.current + 1];
      if (next_slide.image.complete == null || next_slide.image.complete) {
        this.next();
      }
    } else { // we're at the last slide
      this.next();
    }
  }


  //--------------------------------------------------
  this.valid_image = function() {
    if (!this.image)
    {
      return false;
    }
    else {
      return true;
    }
  }

  //--------------------------------------------------
  this.getElementById = function(element_id) {
    if (document.getElementById) {
      return document.getElementById(element_id);
    }
    else if (document.all) {
      return document.all[element_id];
    }
    else if (document.layers) {
      return document.layers[element_id];
    } else {
      return undefined;
    }
  }


  this.set_image = function(imageobject) {
    if (!document.images)
      return;
    this.image = imageobject;
  }


  this.set_textarea = function(textareaobject) {
    this.textarea = textareaobject;
    this.display_text();
  }

  this.set_textid = function(textidstr) {
    this.textid = textidstr;
    this.display_text();
  }
}