1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
|
// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "cc/layers/painted_scrollbar_layer.h"
#include "base/auto_reset.h"
#include "cc/layers/painted_scrollbar_layer_impl.h"
#include "cc/paint/skia_paint_canvas.h"
#include "cc/trees/draw_property_utils.h"
#include "cc/trees/layer_tree_host.h"
#include "third_party/skia/include/core/SkBitmap.h"
namespace cc {
std::unique_ptr<LayerImpl> PaintedScrollbarLayer::CreateLayerImpl(
LayerTreeImpl* tree_impl) {
return PaintedScrollbarLayerImpl::Create(
tree_impl, id(), scrollbar_->Orientation(),
scrollbar_->IsLeftSideVerticalScrollbar(), scrollbar_->IsOverlay());
}
scoped_refptr<PaintedScrollbarLayer> PaintedScrollbarLayer::Create(
std::unique_ptr<Scrollbar> scrollbar) {
return base::WrapRefCounted(new PaintedScrollbarLayer(std::move(scrollbar)));
}
PaintedScrollbarLayer::PaintedScrollbarLayer(
std::unique_ptr<Scrollbar> scrollbar)
: scrollbar_(std::move(scrollbar)),
internal_contents_scale_(1.f),
supports_drag_snap_back_(false),
thumb_thickness_(scrollbar_->ThumbThickness()),
thumb_length_(scrollbar_->ThumbLength()),
is_overlay_(scrollbar_->IsOverlay()),
has_thumb_(scrollbar_->HasThumb()),
thumb_opacity_(scrollbar_->ThumbOpacity()) {}
PaintedScrollbarLayer::~PaintedScrollbarLayer() = default;
bool PaintedScrollbarLayer::OpacityCanAnimateOnImplThread() const {
return scrollbar_->IsOverlay();
}
void PaintedScrollbarLayer::PushPropertiesTo(LayerImpl* layer) {
ScrollbarLayerBase::PushPropertiesTo(layer);
PaintedScrollbarLayerImpl* scrollbar_layer =
static_cast<PaintedScrollbarLayerImpl*>(layer);
scrollbar_layer->set_internal_contents_scale_and_bounds(
internal_contents_scale_, internal_content_bounds_);
scrollbar_layer->SetSupportsDragSnapBack(supports_drag_snap_back_);
scrollbar_layer->SetThumbThickness(thumb_thickness_);
scrollbar_layer->SetBackButtonRect(back_button_rect_);
scrollbar_layer->SetForwardButtonRect(forward_button_rect_);
scrollbar_layer->SetThumbLength(thumb_length_);
if (scrollbar_->Orientation() == HORIZONTAL) {
scrollbar_layer->SetTrackStart(track_rect_.x());
scrollbar_layer->SetTrackLength(track_rect_.width());
} else {
scrollbar_layer->SetTrackStart(track_rect_.y());
scrollbar_layer->SetTrackLength(track_rect_.height());
}
if (track_resource_.get())
scrollbar_layer->set_track_ui_resource_id(track_resource_->id());
else
scrollbar_layer->set_track_ui_resource_id(0);
if (thumb_resource_.get())
scrollbar_layer->set_thumb_ui_resource_id(thumb_resource_->id());
else
scrollbar_layer->set_thumb_ui_resource_id(0);
scrollbar_layer->set_thumb_opacity(thumb_opacity_);
scrollbar_layer->set_is_overlay_scrollbar(is_overlay_);
}
void PaintedScrollbarLayer::SetLayerTreeHost(LayerTreeHost* host) {
// When the LTH is set to null or has changed, then this layer should remove
// all of its associated resources.
if (!host || host != layer_tree_host()) {
track_resource_ = nullptr;
thumb_resource_ = nullptr;
}
ScrollbarLayerBase::SetLayerTreeHost(host);
}
gfx::Rect PaintedScrollbarLayer::ScrollbarLayerRectToContentRect(
const gfx::Rect& layer_rect) const {
// Don't intersect with the bounds as in LayerRectToContentRect() because
// layer_rect here might be in coordinates of the containing layer.
gfx::Rect expanded_rect = gfx::ScaleToEnclosingRectSafe(
layer_rect, internal_contents_scale_, internal_contents_scale_);
// We should never return a rect bigger than the content bounds.
gfx::Size clamped_size = expanded_rect.size();
clamped_size.SetToMin(internal_content_bounds_);
expanded_rect.set_size(clamped_size);
return expanded_rect;
}
gfx::Rect PaintedScrollbarLayer::OriginThumbRect() const {
gfx::Size thumb_size;
if (scrollbar_->Orientation() == HORIZONTAL) {
thumb_size =
gfx::Size(scrollbar_->ThumbLength(), scrollbar_->ThumbThickness());
} else {
thumb_size =
gfx::Size(scrollbar_->ThumbThickness(), scrollbar_->ThumbLength());
}
return gfx::Rect(thumb_size);
}
void PaintedScrollbarLayer::UpdateThumbAndTrackGeometry() {
UpdateProperty(scrollbar_->SupportsDragSnapBack(), &supports_drag_snap_back_);
UpdateProperty(scrollbar_->TrackRect(), &track_rect_);
UpdateProperty(scrollbar_->BackButtonRect(), &back_button_rect_);
UpdateProperty(scrollbar_->ForwardButtonRect(), &forward_button_rect_);
UpdateProperty(scrollbar_->Location(), &location_);
UpdateProperty(scrollbar_->IsOverlay(), &is_overlay_);
UpdateProperty(scrollbar_->HasThumb(), &has_thumb_);
if (has_thumb_) {
UpdateProperty(scrollbar_->ThumbThickness(), &thumb_thickness_);
UpdateProperty(scrollbar_->ThumbLength(), &thumb_length_);
} else {
UpdateProperty(0, &thumb_thickness_);
UpdateProperty(0, &thumb_length_);
}
}
void PaintedScrollbarLayer::UpdateInternalContentScale() {
gfx::Transform transform;
transform = draw_property_utils::ScreenSpaceTransform(
this, layer_tree_host()->property_trees()->transform_tree);
gfx::Vector2dF transform_scales = MathUtil::ComputeTransform2dScaleComponents(
transform, layer_tree_host()->device_scale_factor());
float scale = std::max(transform_scales.x(), transform_scales.y());
bool changed = false;
changed |= UpdateProperty(scale, &internal_contents_scale_);
changed |=
UpdateProperty(gfx::ScaleToCeiledSize(bounds(), internal_contents_scale_),
&internal_content_bounds_);
if (changed) {
// If the content scale or bounds change, repaint.
SetNeedsDisplay();
}
}
bool PaintedScrollbarLayer::Update() {
{
auto ignore_set_needs_commit = IgnoreSetNeedsCommit();
ScrollbarLayerBase::Update();
UpdateInternalContentScale();
}
UpdateThumbAndTrackGeometry();
gfx::Rect track_layer_rect = gfx::Rect(location_, bounds());
gfx::Rect scaled_track_rect = ScrollbarLayerRectToContentRect(
track_layer_rect);
bool updated = false;
if (scaled_track_rect.IsEmpty()) {
if (track_resource_) {
track_resource_ = nullptr;
thumb_resource_ = nullptr;
SetNeedsPushProperties();
updated = true;
}
return updated;
}
if (!has_thumb_ && thumb_resource_) {
thumb_resource_ = nullptr;
SetNeedsPushProperties();
updated = true;
}
if (update_rect().IsEmpty() && track_resource_)
return updated;
if (!track_resource_ || scrollbar_->NeedsPaintPart(TRACK)) {
track_resource_ = ScopedUIResource::Create(
layer_tree_host()->GetUIResourceManager(),
RasterizeScrollbarPart(track_layer_rect, scaled_track_rect, TRACK));
}
gfx::Rect thumb_layer_rect = OriginThumbRect();
gfx::Rect scaled_thumb_rect =
ScrollbarLayerRectToContentRect(thumb_layer_rect);
if (has_thumb_ && !scaled_thumb_rect.IsEmpty()) {
if (!thumb_resource_ || scrollbar_->NeedsPaintPart(THUMB) ||
scaled_thumb_rect.size() !=
thumb_resource_->GetBitmap(0, false).GetSize()) {
thumb_resource_ = ScopedUIResource::Create(
layer_tree_host()->GetUIResourceManager(),
RasterizeScrollbarPart(thumb_layer_rect, scaled_thumb_rect, THUMB));
}
thumb_opacity_ = scrollbar_->ThumbOpacity();
}
// UI resources changed so push properties is needed.
SetNeedsPushProperties();
updated = true;
return updated;
}
UIResourceBitmap PaintedScrollbarLayer::RasterizeScrollbarPart(
const gfx::Rect& layer_rect,
const gfx::Rect& requested_content_rect,
ScrollbarPart part) {
DCHECK(!requested_content_rect.size().IsEmpty());
DCHECK(!layer_rect.size().IsEmpty());
gfx::Rect content_rect = requested_content_rect;
// Pages can end up requesting arbitrarily large scrollbars. Prevent this
// from crashing due to OOM and try something smaller.
SkBitmap skbitmap;
bool allocation_succeeded =
skbitmap.tryAllocN32Pixels(content_rect.width(), content_rect.height());
// Assuming 4bpp, caps at 4M.
constexpr int kMinScrollbarDimension = 1024;
int dimension = std::max(content_rect.width(), content_rect.height()) / 2;
while (!allocation_succeeded && dimension >= kMinScrollbarDimension) {
content_rect.Intersect(gfx::Rect(requested_content_rect.x(),
requested_content_rect.y(), dimension,
dimension));
allocation_succeeded =
skbitmap.tryAllocN32Pixels(content_rect.width(), content_rect.height());
if (!allocation_succeeded)
dimension = dimension / 2;
}
CHECK(allocation_succeeded)
<< "Failed to allocate memory for scrollbar at dimension : " << dimension;
SkiaPaintCanvas canvas(skbitmap);
canvas.clear(SK_ColorTRANSPARENT);
float scale_x =
content_rect.width() / static_cast<float>(layer_rect.width());
float scale_y =
content_rect.height() / static_cast<float>(layer_rect.height());
canvas.scale(SkFloatToScalar(scale_x), SkFloatToScalar(scale_y));
scrollbar_->PaintPart(&canvas, part);
// Make sure that the pixels are no longer mutable to unavoid unnecessary
// allocation and copying.
skbitmap.setImmutable();
return UIResourceBitmap(skbitmap);
}
} // namespace cc
|
