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
|
/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/QuickSort.h>
#include <AK/StringBuilder.h>
#include <LibGfx/Painter.h>
#include <LibWeb/Layout/Box.h>
#include <LibWeb/Layout/InitialContainingBlock.h>
#include <LibWeb/Painting/StackingContext.h>
namespace Web::Layout {
StackingContext::StackingContext(Box& box, StackingContext* parent)
: m_box(box)
, m_parent(parent)
{
VERIFY(m_parent != this);
if (m_parent) {
m_parent->m_children.append(this);
// FIXME: Don't sort on every append..
// FIXME: Apparently this also breaks tree order inside layers
quick_sort(m_parent->m_children, [](auto& a, auto& b) {
return a->m_box.computed_values().z_index().value_or(0) < b->m_box.computed_values().z_index().value_or(0);
});
}
}
void StackingContext::paint_descendants(PaintContext& context, Node& box, StackingContextPaintPhase phase)
{
if (phase == StackingContextPaintPhase::Foreground)
box.before_children_paint(context, PaintPhase::Foreground);
box.for_each_child([&](auto& child) {
if (child.establishes_stacking_context())
return;
switch (phase) {
case StackingContextPaintPhase::BackgroundAndBorders:
if (!child.is_floating() && !child.is_positioned()) {
child.paint(context, PaintPhase::Background);
child.paint(context, PaintPhase::Border);
paint_descendants(context, child, phase);
}
break;
case StackingContextPaintPhase::Floats:
if (!child.is_positioned()) {
if (child.is_floating()) {
child.paint(context, PaintPhase::Background);
child.paint(context, PaintPhase::Border);
paint_descendants(context, child, StackingContextPaintPhase::BackgroundAndBorders);
}
paint_descendants(context, child, phase);
}
break;
case StackingContextPaintPhase::Foreground:
if (!child.is_positioned()) {
child.paint(context, PaintPhase::Foreground);
paint_descendants(context, child, phase);
}
break;
case StackingContextPaintPhase::FocusAndOverlay:
if (context.has_focus()) {
child.paint(context, PaintPhase::FocusOutline);
}
child.paint(context, PaintPhase::Overlay);
paint_descendants(context, child, phase);
break;
}
});
if (phase == StackingContextPaintPhase::Foreground)
box.after_children_paint(context, PaintPhase::Foreground);
}
void StackingContext::paint_internal(PaintContext& context)
{
// For a more elaborate description of the algorithm, see CSS 2.1 Appendix E
// Draw the background and borders for the context root (steps 1, 2)
m_box.paint(context, PaintPhase::Background);
m_box.paint(context, PaintPhase::Border);
// Draw positioned descendants with negative z-indices (step 3)
for (auto* child : m_children) {
if (child->m_box.computed_values().z_index().has_value() && child->m_box.computed_values().z_index().value() < 0)
child->paint(context);
}
// Draw the background and borders for block-level children (step 4)
paint_descendants(context, m_box, StackingContextPaintPhase::BackgroundAndBorders);
// Draw the non-positioned floats (step 5)
paint_descendants(context, m_box, StackingContextPaintPhase::Floats);
// Draw inline content, replaced content, etc. (steps 6, 7)
m_box.paint(context, PaintPhase::Foreground);
paint_descendants(context, m_box, StackingContextPaintPhase::Foreground);
// Draw other positioned descendants (steps 8, 9)
for (auto* child : m_children) {
if (child->m_box.computed_values().z_index().has_value() && child->m_box.computed_values().z_index().value() < 0)
continue;
child->paint(context);
}
m_box.paint(context, PaintPhase::FocusOutline);
m_box.paint(context, PaintPhase::Overlay);
paint_descendants(context, m_box, StackingContextPaintPhase::FocusAndOverlay);
}
void StackingContext::paint(PaintContext& context)
{
auto opacity = m_box.computed_values().opacity();
if (opacity.has_value() && opacity.value() == 0.0f)
return;
if (opacity.has_value() && opacity.value() != 1.0f) {
auto bitmap = context.painter().target();
auto new_bitmap = Gfx::Bitmap::try_create(Gfx::BitmapFormat::BGRA8888, bitmap->size());
if (!new_bitmap)
return;
Gfx::Painter painter(*new_bitmap);
PaintContext paint_context(painter, context.palette(), context.scroll_offset());
paint_internal(paint_context);
context.painter().blit(Gfx::IntPoint(m_box.absolute_position()), *new_bitmap, Gfx::IntRect(m_box.absolute_rect()), opacity.value());
} else {
paint_internal(context);
}
}
HitTestResult StackingContext::hit_test(const Gfx::IntPoint& position, HitTestType type) const
{
HitTestResult result;
if (!is<InitialContainingBlock>(m_box)) {
result = m_box.hit_test(position, type);
} else {
// NOTE: InitialContainingBlock::hit_test() merely calls StackingContext::hit_test()
// so we call its base class instead.
result = verify_cast<InitialContainingBlock>(m_box).BlockBox::hit_test(position, type);
}
int z_index = m_box.computed_values().z_index().value_or(0);
for (auto* child : m_children) {
int child_z_index = child->m_box.computed_values().z_index().value_or(0);
if (result.layout_node && (child_z_index < z_index))
continue;
auto result_here = child->hit_test(position, type);
if (result_here.layout_node)
result = result_here;
}
return result;
}
void StackingContext::dump(int indent) const
{
StringBuilder builder;
for (int i = 0; i < indent; ++i)
builder.append(' ');
builder.appendff("SC for {}({}) {} [children: {}]", m_box.class_name(), m_box.dom_node() ? m_box.dom_node()->node_name().characters() : "(anonymous)", m_box.absolute_rect().to_string().characters(), m_children.size());
dbgln("{}", builder.string_view());
for (auto& child : m_children)
child->dump(indent + 1);
}
}
|
