},
  inspect: function() {
    return '#<Effect:' + $H(this).inspect() + ',options:' + $H(this.options).inspect() + '>';
  }
}

Effect.Parallel = Class.create();
Object.extend(Object.extend(Effect.Parallel.prototype, Effect.Base.prototype), {
  initialize: function(effects) {
    this.effects = effects || [];
    this.start(arguments[1]);
  },
  update: function(position) {
    this.effects.invoke('render', position);
  },
  finish: function(position) {
    this.effects.each( function(effect) {
      effect.render(1.0);
      effect.cancel();
      effect.event('beforeFinish');
      if(effect.finish) effect.finish(position);
      effect.event('afterFinish');
    });
  }
});

Effect.Opacity = Class.create();
Object.extend(Object.extend(Effect.Opacity.prototype, Effect.Base.prototype), {
  initialize: function(element) {
    this.element = $(element);
    // make this work on IE on elements without 'layout'
    if(/MSIE/.test(navigator.userAgent) && (!this.element.hasLayout))
      this.element.setStyle({zoom: 1});
    var options = Object.extend({
      from: this.element.getOpacity() || 0.0,
      to:   1.0
    }, arguments[1] || {});
    this.start(options);
  },
  update: function(position) {
    this.element.setOpacity(position);
  }
});

Effect.Move = Class.create();
Object.extend(Object.extend(Effect.Move.prototype, Effect.Base.prototype), {
  initialize: function(element) {
    this.element = $(element);
    var options = Object.extend({
      x:    0,
      y:    0,
      mode: 'relative'
    }, arguments[1] || {});
    this.start(options);
  },
  setup: function() {
    // Bug in Opera: Opera returns the "real" position of a static element or
    // relative element that does not have top/left explicitly set.
    // ==> Always set top and left for position relative elements in your stylesheets 
    // (to 0 if you do not need them) 
    this.element.makePositioned();
    this.originalLeft = parseFloat(this.element.getStyle('left') || '0');
    this.originalTop  = parseFloat(this.element.getStyle('top')  || '0');
    if(this.options.mode == 'absolute') {
      // absolute movement, so we need to calc deltaX and deltaY
      this.options.x = this.options.x - this.originalLeft;
      this.options.y = this.options.y - this.originalTop;
    }
  },
  update: function(position) {
    this.element.setStyle({
      left: this.options.x  * position + this.originalLeft + 'px',
      top:  this.options.y  * position + this.originalTop  + 'px'
    });
  }
});

// for backwards compatibility
Effect.MoveBy = function(element, toTop, toLeft) {
  return new Effect.Move(element, 
    Object.extend({ x: toLeft, y: toTop }, arguments[3] || {}));
};

Effect.Scale = Class.create();
Object.extend(Object.extend(Effect.Scale.prototype, Effect.Base.prototype), {
  initialize: function(element, percent) {
    this.element = $(element)
    var options = Object.extend({
      scaleX: true,
      scaleY: true,
      scaleContent: true,
      scaleFromCenter: false,
      scaleMode: 'box',        // 'box' or 'contents' or {} with provided values
      scaleFrom: 100.0,
      scaleTo:   percent
    }, arguments[2] || {});
    this.start(options);
  },
  setup: function() {
    this.restoreAfterFinish = this.options.restoreAfterFinish || false;
    this.elementPositioning = this.element.getStyle('position');
    
    this.originalStyle = {};
    ['top','left','width','height','fontSize'].each( function(k) {
      this.originalStyle[k] = this.element.style[k];
    }.bind(this));
      
    this.originalTop  = this.element.offsetTop;
    this.originalLeft = this.element.offsetLeft;
    
    var fontSize = this.element.getStyle('font-size') || '100%';
    ['em','px','%'].each( function(fontSizeType) {
      if(fontSize.indexOf(fontSizeType)>0) {
        this.fontSize     = parseFloat(fontSize);
        this.fontSizeType = fontSizeType;
      }
    }.bind(this));
    
    this.factor = (this.options.scaleTo - this.options.scaleFrom)/100;
    
    this.dims = null;
    if(this.options.scaleMode=='box')
      this.dims = [this.element.offsetHeight, this.element.offsetWidth];
    if(/^content/.test(this.options.scaleMode))
      this.dims = [this.element.scrollHeight, this.element.scrollWidth];
    if(!this.dims)
      this.dims = [this.options.scaleMode.originalHeight,
                   this.options.scaleMode.originalWidth];
  },
  update: function(position) {
    var currentScale = (this.options.scaleFrom/100.0) + (this.factor * position);
    if(this.options.scaleContent && this.fontSize)
      this.element.setStyle({fontSize: this.fontSize * currentScale + this.fontSizeType });
    this.setDimensions(this.dims[0] * currentScale, this.dims[1] * currentScale);
  },
  finish: function(position) {
    if (this.restoreAfterFinish) this.element.setStyle(this.originalStyle);
  },
  setDimensions: function(height, width) {
    var d = {};
    if(this.options.scaleX) d.width = width + 'px';
    if(this.options.scaleY) d.height = height + 'px';
    if(this.options.scaleFromCenter) {
      var topd  = (height - this.dims[0])/2;
      var leftd = (width  - this.dims[1])/2;
      if(this.elementPositioning == 'absolute') {
        if(this.options.scaleY) d.top = this.originalTop-topd + 'px';
        if(this.options.scaleX) d.left = this.originalLeft-leftd + 'px';
      } else {
        if(this.options.scaleY) d.top = -topd + 'px';
        if(this.options.scaleX) d.left = -leftd + 'px';
      }
    }
    this.element.setStyle(d);
  }
});

Effect.Highlight = Class.create();
Object.extend(Object.extend(Effect.Highlight.prototype, Effect.Base.prototype), {
  initialize: function(element) {
    this.element = $(element);
    var options = Object.extend({ startcolor: '#ffff99' }, arguments[1] || {});
    this.start(options);
  },
  setup: function() {
    // Prevent executing on elements not in the layout flow
    if(this.element.getStyle('display')=='none') { this.cancel(); return; }
    // Disable background image during the effect
    this.oldStyle = {
      backgroundImage: this.element.getStyle('background-image') };
    this.element.setStyle({backgroundImage: 'none'});
    if(!this.options.endcolor)
      this.options.endcolor = this.element.getStyle('background-color').parseColor('#ffffff');
    if(!this.options.restorecolor)
      this.options.restorecolor = this.element.getStyle('background-color');
    // init color calculations
    this._base  = $R(0,2).map(function(i){ return parseInt(this.options.startcolor.slice(i*2+1,i*2+3),16) }.bind(this));
    this._delta = $R(0,2).map(function(i){ return parseInt(this.options.endcolor.slice(i*2+1,i*2+3),16)-this._base[i] }.bind(this));
  },
  update: function(position) {
    this.element.setStyle({backgroundColor: $R(0,2).inject('#',function(m,v,i){
      return m+(Math.round(this._base[i]+(this._delta[i]*position)).toColorPart()); }.bind(this)) });
  },
  finish: function() {
    this.element.setStyle(Object.extend(this.oldStyle, {
      backgroundColor: this.options.restorecolor
    }));
  }
});

Effect.ScrollTo = Class.create();
Object.extend(Object.extend(Effect.ScrollTo.prototype, Effect.Base.prototype), {
  initialize: function(element) {
    this.element = $(element);
    this.start(arguments[1] || {});
  },
  setup: function() {
    Position.prepare();
    var offsets = Position.cumulativeOffset(this.element);
    if(this.options.offset) offsets[1] += this.options.offset;
    var max = window.innerHeight ? 
      window.height - window.innerHeight :
      document.body.scrollHeight - 
        (document.documentElement.clientHeight ? 
          document.documentElement.clientHeight : document.body.clientHeight);
    this.scrollStart = Position.deltaY;
    this.delta = (offsets[1] > max ? max : offsets[1]) - this.scrollStart;
  },
  update: function(position) {
    Position.prepare();
    window.scrollTo(Position.deltaX, 
      this.scrollStart + (position*this.delta));
  }
});

/* ------------- combination effects ------------- */

Effect.Fade = function(element) {
  element = $(element);
  var oldOpacity = element.getInlineOpacity();
  var options = Object.extend({
  from: element.getOpacity() || 1.0,
  to:   0.0,
  afterFinishInternal: function(effect) { 
    if(effect.options.to!=0) return;
    effect.element.hide();
    effect.element.setStyle({opacity: oldOpacity}); 
  }}, arguments[1] || {});
  return new Effect.Opacity(element,options);
}

Effect.Appear = function(element) {
  element = $(element);
  var options = Object.extend({
  from: (element.getStyle('display') == 'none' ? 0.0 : element.getOpacity() || 0.0),
  to:   1.0,
  // force Safari to render floated elements properly
  afterFinishInternal: function(effect) {
    effect.element.forceRerendering();
  },
  beforeSetup: function(effect) {
    effect.element.setOpacity(effect.options.from);
    effect.element.show(); 
  }}, arguments[1] || {});
  return new Effect.Opacity(element,options);
}

Effect.Puff = function(element) {
  element = $(element);
  var oldStyle = { opacity: element.getInlineOpacity(), position: element.getStyle('position') };
  return new Effect.Parallel(
   [ new Effect.Scale(element, 200, 
      { sync: true, scaleFromCenter: true, scaleContent: true, restoreAfterFinish: true }), 
     new Effect.Opacity(element, { sync: true, to: 0.0 } ) ], 
     Object.extend({ duration: 1.0, 
      beforeSetupInternal: function(effect) {
        effect.effects[0].element.setStyle({position: 'absolute'}); },
      afterFinishInternal: function(effect) {
         effect.effects[0].element.hide();
         effect.effects[0].element.setStyle(oldStyle); }
     }, arguments[1] || {})
   );
}

Effect.BlindUp = function(element) {
  element = $(element);
  element.makeClipping();
  return new Effect.Scale(element, 0, 
    Object.extend({ scaleContent: false, 
      scaleX: false, 
      restoreAfterFinish: true,
      afterFinishInternal: function(effect) {
        effect.element.hide();
        effect.element.undoClipping();
      } 
    }, arguments[1] || {})
  );
}

Effect.BlindDown = function(element) {
  element = $(element);
  var elementDimensions = element.getDimensions();
  return new Effect.Scale(element, 100, 
    Object.extend({ scaleContent: false, 
      scaleX: false,
      scaleFrom: 0,
      scaleMode: {originalHeight: elementDimensions.height, originalWidth: elementDimensions.width},
      restoreAfterFinish: true,
      afterSetup: function(effect) {
        effect.element.makeClipping();
        effect.element.setStyle({height: '0px'});
        effect.element.show(); 
      },  
      afterFinishInternal: function(effect) {
        effect.element.undoClipping();
      }
    }, arguments[1] || {})
  );
}

Effect.SwitchOff = function(element) {
  element = $(element);
  var oldOpacity = element.getInlineOpacity();
  return new Effect.Appear(element, { 
    duration: 0.4,
    from: 0,
    transition: Effect.Transitions.flicker,
    afterFinishInternal: function(effect) {
      new Effect.Scale(effect.element, 1, { 
        duration: 0.3, scaleFromCenter: true,
        scaleX: false, scaleContent: false, restoreAfterFinish: true,
        beforeSetup: function(effect) { 
          effect.element.makePositioned();
          effect.element.makeClipping();
        },
        afterFinishInternal: function(effect) {
          effect.element.hide();
          effect.element.undoClipping();