/* -------------------------------------------------------
 *   SlideShow.es
 *  Author:    G. Wade Johnson
 *  Created:   11/13/2003
 *  Copyright 2003 G. Wade Johnson
 *  Available for any use if this notice is maintained.
 */

var svgNS   = "http://www.w3.org/2000/svg";
var xlinkNS = "http://www.w3.org/1999/xlink";

//constructor
function  SlideShow( delay, img, ctr, nam )
 {
  this.images   = null;
  this.delay    = (null != delay) ? delay : 1000;
  this.imgElem  = img;
  this.cntrElem = ctr;
  this.nameElem = nam;
  this.curr     = 0;
  this.timer    = null;
  this.running  = false;
 }

SlideShow.prototype.init = function( arr, prot ) {
   this.images = arr;
   this.max    = this.images.length - 1;
   this.display();
   _enable_buttons( prot );
 };

SlideShow.prototype.display = function() {
  var image = this.images[this.curr];
  this.imgElem.setAttributeNS( xlinkNS, "href", image );

  if(null != this.cntrElem)
    setText(this.cntrElem, this.curr+1);

  if(null != this.nameElem)
   {
    var ndx = image.lastIndexOf( '/' );
    if(-1 != ndx)
      image = image.substring( ndx+1 );

    setText(this.nameElem, image);
   }
 };

SlideShow.prototype.first_image = function() {
  this.curr=0;
  this.display();
 };

SlideShow.prototype.first = function() {
  this.stop();
  this.first_image();
 };

SlideShow.prototype.last_image = function() {
  this.curr=this.max;
  this.display();
 };

SlideShow.prototype.last = function() {
  this.stop();
  this.last_image();
 };

SlideShow.prototype.next_image = function() {
  if(++this.curr > this.max)
    this.curr=0;
  this.display();
 };

SlideShow.prototype.next = function() {
  this.stop();
  this.next_image();
 };

SlideShow.prototype.previous_image = function() {
  if(--this.curr < 0)
    this.curr=this.max;
  this.display();
 };

SlideShow.prototype.previous = function() {
  this.stop();
  this.previous_image();
 };

SlideShow.prototype.nextslide = function() {
  if(this.running)
   {
    if(this.curr == this.max)
      this.stop();
    else
      this.next_image();
   }
 };

SlideShow.prototype.slideshow = function( objname ) {
  this.running = true;
  if(null == this.timer)
    this.timer = setInterval( objname+".nextslide()", this.delay );
 };

SlideShow.prototype.stop = function() {
  if(null != this.timer)
   {
//    clearInterval( this.timer );
//    this.timer = null;
      this.running = false;
   }
 };

function  setText(elem, str)
 {
  var text = document.createTextNode( str );
  elem.replaceChild( text, elem.getFirstChild() );
 }

function _enable_buttons( prot )
 {
  if(prot == null)
    return;

  prot.setAttributeNS( null, "pointer-events", "none" );
 }