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 #include "cc/animation/scrollbar_animation_controller_thinning.h"
6
7 #include "base/time/time.h"
8 #include "cc/layers/layer_impl.h"
9 #include "cc/layers/scrollbar_layer_impl_base.h"
10
11 namespace {
12 const float kIdleThicknessScale = 0.4f;
13 const float kIdleOpacity = 0.7f;
14 const float kDefaultMouseMoveDistanceToTriggerAnimation = 25.f;
15 }
16
17 namespace cc {
18
19 scoped_ptr<ScrollbarAnimationControllerThinning>
Create(LayerImpl * scroll_layer,ScrollbarAnimationControllerClient * client,base::TimeDelta delay_before_starting,base::TimeDelta duration)20 ScrollbarAnimationControllerThinning::Create(
21 LayerImpl* scroll_layer,
22 ScrollbarAnimationControllerClient* client,
23 base::TimeDelta delay_before_starting,
24 base::TimeDelta duration) {
25 return make_scoped_ptr(new ScrollbarAnimationControllerThinning(
26 scroll_layer, client, delay_before_starting, duration));
27 }
28
ScrollbarAnimationControllerThinning(LayerImpl * scroll_layer,ScrollbarAnimationControllerClient * client,base::TimeDelta delay_before_starting,base::TimeDelta duration)29 ScrollbarAnimationControllerThinning::ScrollbarAnimationControllerThinning(
30 LayerImpl* scroll_layer,
31 ScrollbarAnimationControllerClient* client,
32 base::TimeDelta delay_before_starting,
33 base::TimeDelta duration)
34 : ScrollbarAnimationController(client, delay_before_starting, duration),
35 scroll_layer_(scroll_layer),
36 mouse_is_over_scrollbar_(false),
37 mouse_is_near_scrollbar_(false),
38 thickness_change_(NONE),
39 opacity_change_(NONE),
40 mouse_move_distance_to_trigger_animation_(
41 kDefaultMouseMoveDistanceToTriggerAnimation) {
42 ApplyOpacityAndThumbThicknessScale(kIdleOpacity, kIdleThicknessScale);
43 }
44
~ScrollbarAnimationControllerThinning()45 ScrollbarAnimationControllerThinning::~ScrollbarAnimationControllerThinning() {
46 }
47
RunAnimationFrame(float progress)48 void ScrollbarAnimationControllerThinning::RunAnimationFrame(float progress) {
49 float opacity = OpacityAtAnimationProgress(progress);
50 float thumb_thickness_scale = ThumbThicknessScaleAtAnimationProgress(
51 progress);
52 ApplyOpacityAndThumbThicknessScale(opacity, thumb_thickness_scale);
53 if (progress == 1.f) {
54 opacity_change_ = NONE;
55 thickness_change_ = NONE;
56 StopAnimation();
57 }
58 }
59
DidMouseMoveOffScrollbar()60 void ScrollbarAnimationControllerThinning::DidMouseMoveOffScrollbar() {
61 mouse_is_over_scrollbar_ = false;
62 mouse_is_near_scrollbar_ = false;
63 opacity_change_ = DECREASE;
64 thickness_change_ = DECREASE;
65 StartAnimation();
66 }
67
DidScrollUpdate()68 void ScrollbarAnimationControllerThinning::DidScrollUpdate() {
69 ScrollbarAnimationController::DidScrollUpdate();
70 ApplyOpacityAndThumbThicknessScale(
71 1, mouse_is_near_scrollbar_ ? 1.f : kIdleThicknessScale);
72
73 if (!mouse_is_over_scrollbar_)
74 opacity_change_ = DECREASE;
75 }
76
DidMouseMoveNear(float distance)77 void ScrollbarAnimationControllerThinning::DidMouseMoveNear(float distance) {
78 bool mouse_is_over_scrollbar = distance == 0.0;
79 bool mouse_is_near_scrollbar =
80 distance < mouse_move_distance_to_trigger_animation_;
81
82 if (mouse_is_over_scrollbar == mouse_is_over_scrollbar_ &&
83 mouse_is_near_scrollbar == mouse_is_near_scrollbar_)
84 return;
85
86 if (mouse_is_over_scrollbar_ != mouse_is_over_scrollbar) {
87 mouse_is_over_scrollbar_ = mouse_is_over_scrollbar;
88 opacity_change_ = mouse_is_over_scrollbar_ ? INCREASE : DECREASE;
89 }
90
91 if (mouse_is_near_scrollbar_ != mouse_is_near_scrollbar) {
92 mouse_is_near_scrollbar_ = mouse_is_near_scrollbar;
93 thickness_change_ = mouse_is_near_scrollbar_ ? INCREASE : DECREASE;
94 }
95
96 StartAnimation();
97 }
98
OpacityAtAnimationProgress(float progress)99 float ScrollbarAnimationControllerThinning::OpacityAtAnimationProgress(
100 float progress) {
101 if (opacity_change_ == NONE)
102 return mouse_is_over_scrollbar_ ? 1.f : kIdleOpacity;
103 float factor = opacity_change_ == INCREASE ? progress : (1.f - progress);
104 float ret = ((1.f - kIdleOpacity) * factor) + kIdleOpacity;
105 return ret;
106 }
107
108 float
ThumbThicknessScaleAtAnimationProgress(float progress)109 ScrollbarAnimationControllerThinning::ThumbThicknessScaleAtAnimationProgress(
110 float progress) {
111 if (thickness_change_ == NONE)
112 return mouse_is_near_scrollbar_ ? 1.f : kIdleThicknessScale;
113 float factor = thickness_change_ == INCREASE ? progress : (1.f - progress);
114 return ((1.f - kIdleThicknessScale) * factor) + kIdleThicknessScale;
115 }
116
AdjustScale(float new_value,float current_value,AnimationChange animation_change)117 float ScrollbarAnimationControllerThinning::AdjustScale(
118 float new_value,
119 float current_value,
120 AnimationChange animation_change) {
121 if (animation_change == INCREASE && current_value > new_value)
122 return current_value;
123 if (animation_change == DECREASE && current_value < new_value)
124 return current_value;
125 return new_value;
126 }
127
ApplyOpacityAndThumbThicknessScale(float opacity,float thumb_thickness_scale)128 void ScrollbarAnimationControllerThinning::ApplyOpacityAndThumbThicknessScale(
129 float opacity, float thumb_thickness_scale) {
130 if (!scroll_layer_->scrollbars())
131 return;
132
133 LayerImpl::ScrollbarSet* scrollbars = scroll_layer_->scrollbars();
134 for (LayerImpl::ScrollbarSet::iterator it = scrollbars->begin();
135 it != scrollbars->end();
136 ++it) {
137 ScrollbarLayerImplBase* scrollbar = *it;
138 if (scrollbar->is_overlay_scrollbar()) {
139 scrollbar->SetOpacity(
140 AdjustScale(opacity, scrollbar->opacity(), opacity_change_));
141 scrollbar->SetThumbThicknessScaleFactor(
142 AdjustScale(thumb_thickness_scale,
143 scrollbar->thumb_thickness_scale_factor(),
144 thickness_change_));
145 }
146 }
147 }
148
149 } // namespace cc
150