cc/animation/scrollbar_animation_controller_thinning.h

   1 // Copyright 2013 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_THINNING_H_
   6 #define CC_ANIMATION_SCROLLBAR_ANIMATION_CONTROLLER_THINNING_H_
   7
   8 #include "base/memory/scoped_ptr.h"
   9 #include "cc/animation/scrollbar_animation_controller.h"
  10 #include "cc/base/cc_export.h"
  11
  12 namespace cc {
  13 class LayerImpl;
  14
  15 // Scrollbar animation that partially fades and thins after an idle delay.
  16 class CC_EXPORT ScrollbarAnimationControllerThinning
  17     : public ScrollbarAnimationController {
  18  public:
  19   static scoped_ptr<ScrollbarAnimationControllerThinning> Create(
  20       LayerImpl* scroll_layer);
  21
  22   static scoped_ptr<ScrollbarAnimationControllerThinning> CreateForTest(
  23       LayerImpl* scroll_layer,
  24       base::TimeDelta animation_delay,
  25       base::TimeDelta animation_duration);
  26
  27   virtual ~ScrollbarAnimationControllerThinning();
  28
  29   void set_mouse_move_distance_for_test(float distance) {
  30     mouse_move_distance_to_trigger_animation_ = distance;
  31   }
  32   bool mouse_is_over_scrollbar() const { return mouse_is_over_scrollbar_; }
  33   bool mouse_is_near_scrollbar() const { return mouse_is_near_scrollbar_; }
  34
  35   // ScrollbarAnimationController overrides.
  36   virtual bool IsAnimating() const OVERRIDE;
  37   virtual base::TimeDelta DelayBeforeStart(base::TimeTicks now) const OVERRIDE;
  38
  39   virtual bool Animate(base::TimeTicks now) OVERRIDE;
  40   virtual void DidScrollGestureBegin() OVERRIDE;
  41   virtual void DidScrollGestureEnd(base::TimeTicks now) OVERRIDE;
  42   virtual void DidMouseMoveOffScrollbar(base::TimeTicks now) OVERRIDE;
  43   virtual bool DidScrollUpdate(base::TimeTicks now) OVERRIDE;
  44   virtual bool DidMouseMoveNear(base::TimeTicks now, float distance) OVERRIDE;
  45
  46  protected:
  47   ScrollbarAnimationControllerThinning(LayerImpl* scroll_layer,
  48                                        base::TimeDelta animation_delay,
  49                                        base::TimeDelta animation_duration);
  50
  51  private:
  52   // Describes whether the current animation should INCREASE (darken / thicken)
  53   // a bar or DECREASE it (lighten / thin).
  54   enum AnimationChange {
  55     NONE,
  56     INCREASE,
  57     DECREASE
  58   };
  59   // Returns how far through the animation we are as a progress value from
  60   // 0 to 1.
  61   float AnimationProgressAtTime(base::TimeTicks now);
  62   float OpacityAtAnimationProgress(float progress);
  63   float ThumbThicknessScaleAtAnimationProgress(float progress);
  64   float AdjustScale(float new_value,
  65                     float current_value,
  66                     AnimationChange animation_change);
  67   void ApplyOpacityAndThumbThicknessScale(float opacity,
  68                                           float thumb_thickness_scale);
  69
  70   LayerImpl* scroll_layer_;
  71
  72   base::TimeTicks last_awaken_time_;
  73   bool mouse_is_over_scrollbar_;
  74   bool mouse_is_near_scrollbar_;
  75   // Are we narrowing or thickening the bars.
  76   AnimationChange thickness_change_;
  77   // Are we darkening or lightening the bars.
  78   AnimationChange opacity_change_;
  79   // Should the animation be delayed or start immediately.
  80   bool should_delay_animation_;
  81   // If |should_delay_animation_| is true, delay the animation by this amount.
  82   base::TimeDelta animation_delay_;
  83   // The time for the animation to run.
  84   base::TimeDelta animation_duration_;
  85   // How close should the mouse be to the scrollbar before we thicken it.
  86   float mouse_move_distance_to_trigger_animation_;
  87
  88   DISALLOW_COPY_AND_ASSIGN(ScrollbarAnimationControllerThinning);
  89 };
  90
  91 }  // namespace cc
  92
  93 #endif  // CC_ANIMATION_SCROLLBAR_ANIMATION_CONTROLLER_THINNING_H_