/*
---
description: Overlay

authors:
  - David Walsh (http://davidwalsh.name)

license:
  - MIT-style license

requires:
  core/1.2.1: '*'

provides:
  - Overlay
...
*/

var Overlay = new Class({
  
  Implements: [Options, Events],
  
  options: {
    id: 'overlay',
    color: '#000',
    duration: 500,
    opacity: 0.5,
    zIndex: 5000/*,
    onClick: $empty,
    onClose: $empty,
    onHide: $empty,
    onOpen: $empty,
    onShow: $empty
    */
  },
  
  initialize: function(container, options){
    this.setOptions(options);
    this.container = document.id(container);
    if (Browser.Engine.trident && Browser.Engine.version <= 6) this.ie6 = true;
    
    this.bound = {
      'window': {
        resize: this.resize.bind(this),
        scroll: this.scroll.bind(this)
      },      
      overlayClick: this.overlayClick.bind(this),
      tweenStart: this.tweenStart.bind(this),
      tweenComplete: this.tweenComplete.bind(this)    
    };
    
    this.build().attach();
  },
  
  build: function(){
    this.overlay = new Element('div', {
      id: this.options.id,
      opacity: 0,
      styles: {
        position: (this.ie6) ? 'absolute' : 'fixed',
        background: this.options.color,
        left: 0,
        top: 0,
        'z-index': this.options.zIndex
      }
    }).inject(this.container);
    this.tween = new Fx.Tween(this.overlay, { 
      duration: this.options.duration,
      link: 'cancel',
      property: 'opacity'
    });
   return this;
  }.protect(),
  
  attach: function(){
    window.addEvents(this.bound.window);
    this.overlay.addEvent('click', this.bound.overlayClick);
    this.tween.addEvents({
      onStart: this.bound.tweenStart,
      onComplete: this.bound.tweenComplete
    });
   return this;
  },
  
  detach: function(){
    var args = Array.prototype.slice.call(arguments);
    args.each(function(item){
      if(item == 'window') window.removeEvents(this.bound.window);
      if(item == 'overlay') this.overlay.removeEvent('click', this.bound.overlayClick);
    }, this);
    return this;
  },
  
  overlayClick: function(){
    this.fireEvent('click');
    return this;
  },
  
  tweenStart: function(){
    this.overlay.setStyles({
      width: '100%',
      height: this.container.getScrollSize().y
    });
   return this;
  },
  
  tweenComplete: function(){
    this.fireEvent(this.overlay.get('opacity') == this.options.opacity ? 'show' : 'hide');
    return this;
  },
  
  open: function(){
    this.fireEvent('open');
    this.tween.start(this.options.opacity);
    return this;
  },
  
  close: function(){
    this.fireEvent('close');
    this.tween.start(0);
    return this;
  },
  
  resize: function(){
    this.fireEvent('resize');
    this.overlay.setStyle('height', this.container.getScrollSize().y);
    return this;
  },
  
  scroll: function(){
    this.fireEvent('scroll');
    if (this.ie6) this.overlay.setStyle('left', window.getScroll().x);
    return this;
  }
  
});