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 "ui/views/controls/scrollbar/overlay_scroll_bar.h"
6
7 #include "third_party/skia/include/core/SkColor.h"
8 #include "third_party/skia/include/core/SkXfermode.h"
9 #include "ui/gfx/canvas.h"
10 #include "ui/views/background.h"
11 #include "ui/views/border.h"
12 #include "ui/views/controls/scrollbar/base_scroll_bar_thumb.h"
13
14 namespace views {
15 namespace {
16
17 const int kScrollbarWidth = 10;
18 const int kThumbInsetInside = 3;
19 const int kThumbInsetFromEdge = 1;
20 const int kThumbCornerRadius = 2;
21 const int kThumbMinimumSize = kScrollbarWidth;
22 const int kThumbHoverAlpha = 128;
23 const int kThumbDefaultAlpha = 64;
24
25 class OverlayScrollBarThumb : public BaseScrollBarThumb,
26 public gfx::AnimationDelegate {
27 public:
28 explicit OverlayScrollBarThumb(BaseScrollBar* scroll_bar);
29 virtual ~OverlayScrollBarThumb();
30
31 protected:
32 // View overrides:
33 virtual gfx::Size GetPreferredSize() const OVERRIDE;
34 virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
35
36 // gfx::AnimationDelegate overrides:
37 virtual void AnimationProgressed(const gfx::Animation* animation) OVERRIDE;
38
39 private:
40 double animation_opacity_;
41 DISALLOW_COPY_AND_ASSIGN(OverlayScrollBarThumb);
42 };
43
OverlayScrollBarThumb(BaseScrollBar * scroll_bar)44 OverlayScrollBarThumb::OverlayScrollBarThumb(BaseScrollBar* scroll_bar)
45 : BaseScrollBarThumb(scroll_bar),
46 animation_opacity_(0.0) {
47 // This is necessary, otherwise the thumb will be rendered below the views if
48 // those views paint to their own layers.
49 SetPaintToLayer(true);
50 SetFillsBoundsOpaquely(false);
51 }
52
~OverlayScrollBarThumb()53 OverlayScrollBarThumb::~OverlayScrollBarThumb() {
54 }
55
GetPreferredSize() const56 gfx::Size OverlayScrollBarThumb::GetPreferredSize() const {
57 return gfx::Size(kThumbMinimumSize, kThumbMinimumSize);
58 }
59
OnPaint(gfx::Canvas * canvas)60 void OverlayScrollBarThumb::OnPaint(gfx::Canvas* canvas) {
61 gfx::Rect local_bounds(GetLocalBounds());
62 SkPaint paint;
63 int alpha = kThumbDefaultAlpha * animation_opacity_;
64 if (GetState() == CustomButton::STATE_HOVERED) {
65 alpha = kThumbHoverAlpha * animation_opacity_;
66 } else if(GetState() == CustomButton::STATE_PRESSED) {
67 // If we are in pressed state, no need to worry about animation,
68 // just display the deeper color.
69 alpha = kThumbHoverAlpha;
70 }
71
72 paint.setStyle(SkPaint::kFill_Style);
73 paint.setColor(SkColorSetARGB(alpha, 0, 0, 0));
74 canvas->DrawRoundRect(local_bounds, kThumbCornerRadius, paint);
75 }
76
AnimationProgressed(const gfx::Animation * animation)77 void OverlayScrollBarThumb::AnimationProgressed(
78 const gfx::Animation* animation) {
79 animation_opacity_ = animation->GetCurrentValue();
80 SchedulePaint();
81 }
82
83 } // namespace
84
OverlayScrollBar(bool horizontal)85 OverlayScrollBar::OverlayScrollBar(bool horizontal)
86 : BaseScrollBar(horizontal, new OverlayScrollBarThumb(this)),
87 animation_(static_cast<OverlayScrollBarThumb*>(GetThumb())) {
88 set_notify_enter_exit_on_child(true);
89 }
90
~OverlayScrollBar()91 OverlayScrollBar::~OverlayScrollBar() {
92 }
93
GetTrackBounds() const94 gfx::Rect OverlayScrollBar::GetTrackBounds() const {
95 gfx::Rect local_bounds(GetLocalBounds());
96 if (IsHorizontal()) {
97 local_bounds.Inset(kThumbInsetFromEdge, kThumbInsetInside,
98 kThumbInsetFromEdge, kThumbInsetFromEdge);
99 } else {
100 local_bounds.Inset(kThumbInsetInside, kThumbInsetFromEdge,
101 kThumbInsetFromEdge, kThumbInsetFromEdge);
102 }
103 gfx::Size track_size = local_bounds.size();
104 track_size.SetToMax(GetThumb()->size());
105 local_bounds.set_size(track_size);
106 return local_bounds;
107 }
108
GetLayoutSize() const109 int OverlayScrollBar::GetLayoutSize() const {
110 return 0;
111 }
112
GetContentOverlapSize() const113 int OverlayScrollBar::GetContentOverlapSize() const {
114 return kScrollbarWidth;
115 }
116
OnMouseEnteredScrollView(const ui::MouseEvent & event)117 void OverlayScrollBar::OnMouseEnteredScrollView(const ui::MouseEvent& event) {
118 animation_.Show();
119 }
120
OnMouseExitedScrollView(const ui::MouseEvent & event)121 void OverlayScrollBar::OnMouseExitedScrollView(const ui::MouseEvent& event) {
122 animation_.Hide();
123 }
124
OnGestureEvent(ui::GestureEvent * event)125 void OverlayScrollBar::OnGestureEvent(ui::GestureEvent* event) {
126 switch (event->type()) {
127 case ui::ET_GESTURE_SCROLL_BEGIN:
128 animation_.Show();
129 break;
130 case ui::ET_GESTURE_SCROLL_END:
131 case ui::ET_SCROLL_FLING_START:
132 case ui::ET_GESTURE_END:
133 animation_.Hide();
134 break;
135 default:
136 break;
137 }
138 BaseScrollBar::OnGestureEvent(event);
139 }
140
GetPreferredSize() const141 gfx::Size OverlayScrollBar::GetPreferredSize() const {
142 return gfx::Size();
143 }
144
Layout()145 void OverlayScrollBar::Layout() {
146 gfx::Rect thumb_bounds = GetTrackBounds();
147 BaseScrollBarThumb* thumb = GetThumb();
148 if (IsHorizontal()) {
149 thumb_bounds.set_x(thumb->x());
150 thumb_bounds.set_width(thumb->width());
151 } else {
152 thumb_bounds.set_y(thumb->y());
153 thumb_bounds.set_height(thumb->height());
154 }
155 thumb->SetBoundsRect(thumb_bounds);
156 }
157
OnPaint(gfx::Canvas * canvas)158 void OverlayScrollBar::OnPaint(gfx::Canvas* canvas) {
159 }
160
161 } // namespace views
162