/**
Script: Slideshow.Fold.js
  Slideshow.Fold - Flash extension for Slideshow.

License:
  MIT-style license.

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

Dependencies:
  Slideshow.
*/

Slideshow.Fold = new Class({
  Extends: Slideshow,
  
/**
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.Fold(element, data, options);
*/

  initialize: function(el, data, options){
    this.parent(el, data, options);
  },

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

  _show: function(fast){
    if (!this.image.retrieve('tween')){
      var options = (this.options.overlap) ? {'duration': this.options.duration} : {'duration': this.options.duration / 2};
      $$(this.a, this.b).set('tween', $merge(options, {'link': 'chain', 'onStart': this._start.bind(this), 'onComplete': this._complete.bind(this), 'property': 'clip', 'transition': this.options.transition}));
    }
    var rect = this._rect(this.image);
    var img = (this.counter % 2) ? this.a : this.b;
    if (fast){      
      img.get('tween').cancel().set('rect(0, 0, 0, 0)');
      this.image.get('tween').cancel().set('rect(auto, auto, auto, auto)');       
    } 
    else {
      if (this.options.overlap){  
        img.get('tween').set('rect(auto, auto, auto, auto)');
        var tween = this.image.get('tween').set(rect.top + ' ' + rect.left + ' ' + Math.ceil(rect.bottom / 2) + ' ' + rect.left).start(rect.top + ' ' + rect.right + ' ' + Math.ceil(rect.bottom / 2) + ' ' + rect.left).start(rect.top + ' ' + rect.right + ' ' + rect.bottom + ' ' + rect.left);
      } 
      else  {
        var fn = function(rect){
          this.image.get('tween').set(rect.top + ' ' + rect.left + ' ' + Math.ceil(rect.bottom / 2) + ' ' + rect.left).start(rect.top + ' ' + rect.right + ' ' + Math.ceil(rect.bottom / 2) + ' ' + rect.left).start(rect.top + ' ' + rect.right + ' ' + rect.bottom + ' ' + rect.left);
        }.pass(rect, this);
        var rect = this._rect(img);
        img.get('tween').set(rect.top + ' ' + rect.right + ' ' + rect.bottom + ' ' + rect.left).start(rect.top + ' ' + rect.right + ' ' + Math.ceil(rect.bottom / 2) + ' ' + rect.left).start(rect.top + ' ' + rect.left + ' ' + Math.ceil(rect.bottom / 2) + ' ' + rect.left).chain(fn);
      }
    }
  },
  
  /**
  Private method: rect
    Calculates the clipping rect
  */

  _rect: function(img){
    var rect = img.getCoordinates(this.slideshow.retrieve('images'));
    rect.right = (rect.right > this.width) ? this.width - rect.left : rect.width;
    rect.bottom = (rect.bottom > this.height) ? this.height - rect.top : rect.height;
    rect.top = (rect.top < 0) ? Math.abs(rect.top) : 0;
    rect.left = (rect.left < 0) ? Math.abs(rect.left) : 0;
    return rect;    
  }
});