/**
Script: Slideshow.KenBurns.js
  Slideshow.KenBurns - KenBurns extension for Slideshow, includes zooming and panning effects.

License:
  MIT-style license.

Copyright:
  Copyright (c) 2008 [Aeron Glemann](http://www.electricprism.com/aeron/).
  
Dependencies:
  Slideshow.
*/

Slideshow.KenBurns = new Class({
  Extends: Slideshow,
  
  options: {
    pan: [100, 100],
    zoom: [50, 50]
  },
  
/**
Constructor: initialize
  Creates an instance of the Slideshow class.

Arguments:
  element - (element) The wrapper element.
  data - (array or object) The images and optional thumbnails, captions and links for the show.
  options - (object) The options below.

Syntax:
  var myShow = new Slideshow.KenBurns(element, data, options);
*/

  initialize: function(el, data, options){
    options.overlap = true;
    options.resize = true;
    ['pan', 'zoom'].each(function(p){
        if ($chk(this[p])){
          if ($type(this[p]) != 'array') this[p] = [this[p], this[p]];
          this[p].map(function(n){return (n.toInt() || 0).limit(0, 100);});          
        }
    }, options);
    this.parent(el, data, options);
  },

/**
Private method: show
  Does the slideshow effect.
*/

  _show: function(fast){
    if (!this.image.retrieve('morph')){
      ['a', 'b'].each(function(image){
        this[image].set('tween', {
          'duration': this.options.duration, 'link': 'cancel', 'onStart': this._start.bind(this), 'onComplete': this._complete.bind(this), 'property': 'opacity'}
        ).get('morph', {
          'duration': (this.options.delay + this.options.duration * 2), 'link': 'cancel', 'transition': $arguments(0)}
        );
      }, this);
    }
    this.image.set('styles', {'bottom': 'auto', 'left': 'auto', 'right': 'auto', 'top': 'auto'});
    var props = ['top left', 'top right', 'bottom left', 'bottom right'][this.counter % 4].split(' ');
    props.each(function(prop){this.image.setStyle(prop, 0);}, this);
    dh = this.height / this.preloader.height;
    dw = this.width / this.preloader.width;
    delta = (dw > dh) ? dw : dh;
    var values = {};
    var zoom = ($random.run(this.options.zoom) / 100.0) + 1;
    var pan = Math.abs(($random.run(this.options.pan) / 100.0) - 1);
    ['height', 'width'].each(function(prop, i){
      var e = Math.ceil(this.preloader[prop] * delta);
      var s = (e * zoom).toInt();    
      values[prop] = [s, e];
      if (dw > dh || i){
        e = (this[prop] - this.image[prop]);
        s = (e * pan).toInt();      
        values[props[i]] = [s, e];
      }
    }, this);
    var paused = (this.firstrun && this.options.paused);
    if (fast || paused){
      this._center(this.image);
      this.image.get('morph').cancel();
      if (paused)
        this.image.get('tween').cancel().set(0).start(1);
      else
        this.image.get('tween').cancel().set(1);
    } 
    else{
      this.image.get('morph').start(values);
      this.image.get('tween').set(0).start(1);
    }
  }
});