ladybird/Libraries/LibHTML/Layout/LayoutBlock.cpp
Andreas Kling 847072c2b1 LibHTML: Respect the link color set via <body link>
The default style for "a" tags now has { color: -libhtml-link; }.
We implement this vendor-specific property by querying the containing
document for the appropriate link color.

Currently we only use the basic link color, but in the future this can
be extended to remember visited links, etc.
2019-10-06 10:25:08 +02:00

251 lines
8.8 KiB
C++

#include <LibGUI/GPainter.h>
#include <LibHTML/CSS/StyleResolver.h>
#include <LibHTML/DOM/Element.h>
#include <LibHTML/Layout/LayoutBlock.h>
#include <LibHTML/Layout/LayoutInline.h>
LayoutBlock::LayoutBlock(const Node* node, NonnullRefPtr<StyleProperties> style_properties)
: LayoutNode(node, move(style_properties))
{
}
LayoutBlock::~LayoutBlock()
{
}
LayoutNode& LayoutBlock::inline_wrapper()
{
if (!last_child() || !last_child()->is_block() || last_child()->node() != nullptr) {
append_child(adopt(*new LayoutBlock(nullptr, style_for_anonymous_block())));
}
return *last_child();
}
void LayoutBlock::layout()
{
compute_width();
compute_position();
if (children_are_inline())
layout_inline_children();
else
layout_block_children();
compute_height();
}
void LayoutBlock::layout_block_children()
{
ASSERT(!children_are_inline());
int content_height = 0;
for_each_child([&](auto& child) {
child.layout();
content_height = child.rect().bottom() + child.box_model().full_margin().bottom - rect().top();
});
rect().set_height(content_height);
}
void LayoutBlock::layout_inline_children()
{
ASSERT(children_are_inline());
m_line_boxes.clear();
for_each_child([&](auto& child) {
ASSERT(child.is_inline());
child.split_into_lines(*this);
});
int content_height = 0;
for (auto& line_box : m_line_boxes) {
int max_height = 0;
for (auto& fragment : line_box.fragments()) {
max_height = max(max_height, fragment.rect().height());
}
for (auto& fragment : line_box.fragments()) {
// Vertically align everyone's bottom to the line.
// FIXME: Support other kinds of vertical alignment.
fragment.rect().set_x(rect().x() + fragment.rect().x());
fragment.rect().set_y(rect().y() + content_height + (max_height - fragment.rect().height()));
if (fragment.layout_node().is_replaced())
const_cast<LayoutNode&>(fragment.layout_node()).set_rect(fragment.rect());
}
content_height += max_height;
}
rect().set_height(content_height);
}
void LayoutBlock::compute_width()
{
auto& style_properties = this->style();
auto auto_value = Length();
auto zero_value = Length(0, Length::Type::Absolute);
auto width = style_properties.length_or_fallback("width", auto_value);
auto margin_left = style_properties.length_or_fallback("margin-left", zero_value);
auto margin_right = style_properties.length_or_fallback("margin-right", zero_value);
auto border_left = style_properties.length_or_fallback("border-left", zero_value);
auto border_right = style_properties.length_or_fallback("border-right", zero_value);
auto padding_left = style_properties.length_or_fallback("padding-left", zero_value);
auto padding_right = style_properties.length_or_fallback("padding-right", zero_value);
#ifdef HTML_DEBUG
dbg() << " Left: " << margin_left << "+" << border_left << "+" << padding_left;
dbg() << "Right: " << margin_right << "+" << border_right << "+" << padding_right;
#endif
int total_px = 0;
for (auto& value : { margin_left, border_left, padding_left, width, padding_right, border_right, margin_right }) {
total_px += value.to_px();
}
#ifdef HTML_DEBUG
dbg() << "Total: " << total_px;
#endif
// 10.3.3 Block-level, non-replaced elements in normal flow
// If 'width' is not 'auto' and 'border-left-width' + 'padding-left' + 'width' + 'padding-right' + 'border-right-width' (plus any of 'margin-left' or 'margin-right' that are not 'auto') is larger than the width of the containing block, then any 'auto' values for 'margin-left' or 'margin-right' are, for the following rules, treated as zero.
if (width.is_auto() && total_px > containing_block()->rect().width()) {
if (margin_left.is_auto())
margin_left = zero_value;
if (margin_right.is_auto())
margin_right = zero_value;
}
// 10.3.3 cont'd.
auto underflow_px = containing_block()->rect().width() - total_px;
if (width.is_auto()) {
if (margin_left.is_auto())
margin_left = zero_value;
if (margin_right.is_auto())
margin_right = zero_value;
if (underflow_px >= 0) {
width = Length(underflow_px, Length::Type::Absolute);
} else {
width = zero_value;
margin_right = Length(margin_right.to_px() + underflow_px, Length::Type::Absolute);
}
} else {
if (!margin_left.is_auto() && !margin_right.is_auto()) {
margin_right = Length(margin_right.to_px() + underflow_px, Length::Type::Absolute);
} else if (!margin_left.is_auto() && margin_right.is_auto()) {
margin_right = Length(underflow_px, Length::Type::Absolute);
} else if (margin_left.is_auto() && !margin_right.is_auto()) {
margin_left = Length(underflow_px, Length::Type::Absolute);
} else { // margin_left.is_auto() && margin_right.is_auto()
auto half_of_the_underflow = Length(underflow_px / 2, Length::Type::Absolute);
margin_left = half_of_the_underflow;
margin_right = half_of_the_underflow;
}
}
rect().set_width(width.to_px());
box_model().margin().left = margin_left;
box_model().margin().right = margin_right;
box_model().border().left = border_left;
box_model().border().right = border_right;
box_model().padding().left = padding_left;
box_model().padding().right = padding_right;
}
void LayoutBlock::compute_position()
{
auto& style_properties = this->style();
auto auto_value = Length();
auto zero_value = Length(0, Length::Type::Absolute);
auto width = style_properties.length_or_fallback("width", auto_value);
box_model().margin().top = style_properties.length_or_fallback("margin-top", zero_value);
box_model().margin().bottom = style_properties.length_or_fallback("margin-bottom", zero_value);
box_model().border().top = style_properties.length_or_fallback("border-top", zero_value);
box_model().border().bottom = style_properties.length_or_fallback("border-bottom", zero_value);
box_model().padding().top = style_properties.length_or_fallback("padding-top", zero_value);
box_model().padding().bottom = style_properties.length_or_fallback("padding-bottom", zero_value);
rect().set_x(containing_block()->rect().x() + box_model().margin().left.to_px() + box_model().border().left.to_px() + box_model().padding().left.to_px());
int top_border = -1;
if (previous_sibling() != nullptr) {
auto& previous_sibling_rect = previous_sibling()->rect();
auto& previous_sibling_style = previous_sibling()->box_model();
top_border = previous_sibling_rect.y() + previous_sibling_rect.height();
top_border += previous_sibling_style.full_margin().bottom;
} else {
top_border = containing_block()->rect().y();
}
rect().set_y(top_border + box_model().full_margin().top);
}
void LayoutBlock::compute_height()
{
auto& style_properties = this->style();
auto height_property = style_properties.property("height");
if (!height_property.has_value())
return;
auto height_length = height_property.value()->to_length();
if (height_length.is_absolute())
rect().set_height(height_length.to_px());
}
void LayoutBlock::render(RenderingContext& context)
{
LayoutNode::render(context);
// FIXME: position this properly
if (style().string_or_fallback("display", "block") == "list-item") {
Rect bullet_rect {
rect().x() - 8,
rect().y() + 4,
3,
3
};
context.painter().fill_rect(bullet_rect, style().color_or_fallback("color", document(), Color::Black));
}
if (children_are_inline()) {
for (auto& line_box : m_line_boxes) {
for (auto& fragment : line_box.fragments()) {
fragment.render(context);
}
}
}
}
bool LayoutBlock::children_are_inline() const
{
return first_child() && !first_child()->is_block();
}
HitTestResult LayoutBlock::hit_test(const Point& position) const
{
if (!children_are_inline())
return LayoutNode::hit_test(position);
HitTestResult result;
for (auto& line_box : m_line_boxes) {
for (auto& fragment : line_box.fragments()) {
if (fragment.rect().contains(position)) {
return { fragment.layout_node() };
}
}
}
return {};
}
NonnullRefPtr<StyleProperties> LayoutBlock::style_for_anonymous_block() const
{
auto new_style = StyleProperties::create();
style().for_each_property([&](auto& name, auto& value) {
if (StyleResolver::is_inherited_property(name))
new_style->set_property(name, value);
});
return new_style;
}