text: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #ifndef ASH_SCREEN_ROTATION_H_
  #define ASH_SCREEN_ROTATION_H_
  
  #include "ash/ash_export.h"
  #include "base/basictypes.h"
  #include "base/memory/scoped_ptr.h"
  #include "ui/compositor/layer_animation_element.h"
  #include "ui/gfx/point.h"
  
  namespace ui {
  class InterpolatedTransform;
  class Layer;
  }
  
  namespace aura {
  class RootWindow;
  }
  
  namespace ash {
  
  // A screen rotation represents a single transition from one screen orientation
  // to another. The  intended usage is that a new instance of the class is
  // created for every transition. It is possible to update the target orientation
  // in the middle of a transition.
  class ASH_EXPORT ScreenRotation : public ui::LayerAnimationElement {
   public:
    // |degrees| are clockwise. |layer| is the target of the animation. Does not
    // take ownership of |layer|.
    ScreenRotation(int degrees, ui::Layer* layer);
    virtual ~ScreenRotation();
  
   private:
    // Generates the intermediate transformation matrices used during the
    // animation.
    void InitTransform(ui::Layer* layer);
  
    // Implementation of ui::LayerAnimationDelegate
    virtual void OnStart(ui::LayerAnimationDelegate* delegate) OVERRIDE;
    virtual bool OnProgress(double t,
                            ui::LayerAnimationDelegate* delegate) OVERRIDE;
    virtual void OnGetTarget(TargetValue* target) const OVERRIDE;
    virtual void OnAbort(ui::LayerAnimationDelegate* delegate) OVERRIDE;
  
    scoped_ptr<ui::InterpolatedTransform> interpolated_transform_;
  
    // The number of degrees to rotate.
    int degrees_;
  
    // The target origin.
    gfx::Point new_origin_;
  
    DISALLOW_COPY_AND_ASSIGN(ScreenRotation);
  };
  
  }  // namespace ash
  
  #endif  // ASH_SCREEN_ROTATION_H_
  