ash/shelf/background_animator.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef ASH_SHELF_BACKGROUND_ANIMATOR_H_
   6 #define ASH_SHELF_BACKGROUND_ANIMATOR_H_
   7
   8 #include "ash/ash_export.h"
   9 #include "base/basictypes.h"
  10 #include "ui/base/animation/animation_delegate.h"
  11 #include "ui/base/animation/slide_animation.h"
  12
  13 namespace ash {
  14 namespace internal {
  15
  16 // Delegate is notified any time the background changes.
  17 class ASH_EXPORT BackgroundAnimatorDelegate {
  18  public:
  19   virtual void UpdateBackground(int alpha) = 0;
  20
  21  protected:
  22   virtual ~BackgroundAnimatorDelegate() {}
  23 };
  24
  25 // BackgroundAnimator is used by the shelf to animate the background (alpha).
  26 class ASH_EXPORT BackgroundAnimator : public ui::AnimationDelegate {
  27  public:
  28   // How the background can be changed.
  29   enum ChangeType {
  30     CHANGE_ANIMATE,
  31     CHANGE_IMMEDIATE
  32   };
  33
  34   BackgroundAnimator(BackgroundAnimatorDelegate* delegate,
  35                      int min_alpha,
  36                      int max_alpha);
  37   virtual ~BackgroundAnimator();
  38
  39   // Sets the transition time in ms.
  40   void SetDuration(int time_in_ms);
  41
  42   // Sets whether a background is rendered. Initial value is false. If |type|
  43   // is |CHANGE_IMMEDIATE| and an animation is not in progress this notifies
  44   // the delegate immediately (synchronously from this method).
  45   void SetPaintsBackground(bool value, ChangeType type);
  46   bool paints_background() const { return paints_background_; }
  47
  48   // Current alpha.
  49   int alpha() const { return alpha_; }
  50
  51   // ui::AnimationDelegate overrides:
  52   virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
  53
  54  private:
  55   BackgroundAnimatorDelegate* delegate_;
  56
  57   const int min_alpha_;
  58   const int max_alpha_;
  59
  60   ui::SlideAnimation animation_;
  61
  62   // Whether the background is painted.
  63   bool paints_background_;
  64
  65   // Current alpha value of the background.
  66   int alpha_;
  67
  68   DISALLOW_COPY_AND_ASSIGN(BackgroundAnimator);
  69 };
  70
  71 }  // namespace internal
  72 }  // namespace ash
  73
  74 #endif  // ASH_SHELF_BACKGROUND_ANIMATOR_H_