cc/animation/scrollbar_animation_controller.h

   1 // Copyright 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 CC_ANIMATION_SCROLLBAR_ANIMATION_CONTROLLER_H_
   6 #define CC_ANIMATION_SCROLLBAR_ANIMATION_CONTROLLER_H_
   7
   8 #include "base/cancelable_callback.h"
   9 #include "base/memory/weak_ptr.h"
  10 #include "base/time/time.h"
  11 #include "cc/base/cc_export.h"
  12 #include "ui/gfx/vector2d_f.h"
  13
  14 namespace cc {
  15
  16 class CC_EXPORT ScrollbarAnimationControllerClient {
  17  public:
  18   virtual ~ScrollbarAnimationControllerClient() {}
  19
  20   virtual void PostDelayedScrollbarFade(const base::Closure& start_fade,
  21                                         base::TimeDelta delay) = 0;
  22   virtual void SetNeedsScrollbarAnimationFrame() = 0;
  23 };
  24
  25 // This abstract class represents the compositor-side analogy of
  26 // ScrollbarAnimator.  Individual platforms should subclass it to provide
  27 // specialized implementation.
  28 class CC_EXPORT ScrollbarAnimationController {
  29  public:
  30   virtual ~ScrollbarAnimationController();
  31
  32   void Animate(base::TimeTicks now);
  33
  34   virtual void DidScrollBegin();
  35   virtual void DidScrollUpdate();
  36   virtual void DidScrollEnd();
  37   virtual void DidMouseMoveOffScrollbar() {}
  38   virtual void DidMouseMoveNear(float distance) {}
  39
  40  protected:
  41   ScrollbarAnimationController(ScrollbarAnimationControllerClient* client,
  42                                base::TimeDelta delay_before_starting,
  43                                base::TimeDelta duration);
  44
  45   virtual void RunAnimationFrame(float progress) = 0;
  46
  47   void StartAnimation();
  48   void StopAnimation();
  49
  50  private:
  51   // Returns how far through the animation we are as a progress value from
  52   // 0 to 1.
  53   float AnimationProgressAtTime(base::TimeTicks now);
  54
  55   void PostDelayedFade();
  56
  57   ScrollbarAnimationControllerClient* client_;
  58   base::TimeTicks last_awaken_time_;
  59   base::TimeDelta delay_before_starting_;
  60   base::TimeDelta duration_;
  61   bool is_animating_;
  62
  63   bool currently_scrolling_;
  64   bool scroll_gesture_has_scrolled_;
  65   base::CancelableClosure delayed_scrollbar_fade_;
  66
  67   base::WeakPtrFactory<ScrollbarAnimationController> weak_factory_;
  68 };
  69
  70 }  // namespace cc
  71
  72 #endif  // CC_ANIMATION_SCROLLBAR_ANIMATION_CONTROLLER_H_