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 // and reacts to mouse movements. 17 class CC_EXPORT ScrollbarAnimationControllerThinning 18 : public ScrollbarAnimationController { 19 public: 20 static scoped_ptr<ScrollbarAnimationControllerThinning> Create( 21 LayerImpl* scroll_layer, 22 ScrollbarAnimationControllerClient* client, 23 base::TimeDelta delay_before_starting, 24 base::TimeDelta duration); 25 26 virtual ~ScrollbarAnimationControllerThinning(); 27 set_mouse_move_distance_for_test(float distance)28 void set_mouse_move_distance_for_test(float distance) { 29 mouse_move_distance_to_trigger_animation_ = distance; 30 } mouse_is_over_scrollbar()31 bool mouse_is_over_scrollbar() const { return mouse_is_over_scrollbar_; } mouse_is_near_scrollbar()32 bool mouse_is_near_scrollbar() const { return mouse_is_near_scrollbar_; } 33 34 virtual void DidScrollUpdate() OVERRIDE; 35 virtual void DidMouseMoveOffScrollbar() OVERRIDE; 36 virtual void DidMouseMoveNear(float distance) OVERRIDE; 37 38 protected: 39 ScrollbarAnimationControllerThinning( 40 LayerImpl* scroll_layer, 41 ScrollbarAnimationControllerClient* client, 42 base::TimeDelta delay_before_starting, 43 base::TimeDelta duration); 44 45 virtual void RunAnimationFrame(float progress) OVERRIDE; 46 47 private: 48 // Describes whether the current animation should INCREASE (darken / thicken) 49 // a bar or DECREASE it (lighten / thin). 50 enum AnimationChange { 51 NONE, 52 INCREASE, 53 DECREASE 54 }; 55 float OpacityAtAnimationProgress(float progress); 56 float ThumbThicknessScaleAtAnimationProgress(float progress); 57 float AdjustScale(float new_value, 58 float current_value, 59 AnimationChange animation_change); 60 void ApplyOpacityAndThumbThicknessScale(float opacity, 61 float thumb_thickness_scale); 62 63 LayerImpl* scroll_layer_; 64 65 bool mouse_is_over_scrollbar_; 66 bool mouse_is_near_scrollbar_; 67 // Are we narrowing or thickening the bars. 68 AnimationChange thickness_change_; 69 // Are we darkening or lightening the bars. 70 AnimationChange opacity_change_; 71 // How close should the mouse be to the scrollbar before we thicken it. 72 float mouse_move_distance_to_trigger_animation_; 73 74 DISALLOW_COPY_AND_ASSIGN(ScrollbarAnimationControllerThinning); 75 }; 76 77 } // namespace cc 78 79 #endif // CC_ANIMATION_SCROLLBAR_ANIMATION_CONTROLLER_THINNING_H_ 80