ladybird/Userland/Libraries/LibWeb/Layout/LayoutState.cpp

236 lines
10 KiB
C++

/*
* Copyright (c) 2022, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibWeb/Layout/BlockContainer.h>
#include <LibWeb/Layout/LayoutState.h>
#include <LibWeb/Layout/TextNode.h>
namespace Web::Layout {
LayoutState::UsedValues& LayoutState::get_mutable(NodeWithStyleAndBoxModelMetrics const& box)
{
auto serial_id = box.serial_id();
if (used_values_per_layout_node[serial_id])
return *used_values_per_layout_node[serial_id];
for (auto const* ancestor = m_parent; ancestor; ancestor = ancestor->m_parent) {
if (ancestor->used_values_per_layout_node[serial_id]) {
auto cow_used_values = adopt_own(*new UsedValues(*ancestor->used_values_per_layout_node[serial_id]));
auto* cow_used_values_ptr = cow_used_values.ptr();
used_values_per_layout_node[serial_id] = move(cow_used_values);
return *cow_used_values_ptr;
}
}
auto const* containing_block_used_values = box.is_initial_containing_block_box() ? nullptr : &get(*box.containing_block());
used_values_per_layout_node[serial_id] = adopt_own(*new UsedValues);
used_values_per_layout_node[serial_id]->set_node(const_cast<NodeWithStyleAndBoxModelMetrics&>(box), containing_block_used_values);
return *used_values_per_layout_node[serial_id];
}
LayoutState::UsedValues const& LayoutState::get(NodeWithStyleAndBoxModelMetrics const& box) const
{
auto serial_id = box.serial_id();
if (used_values_per_layout_node[serial_id])
return *used_values_per_layout_node[serial_id];
for (auto* ancestor = m_parent; ancestor; ancestor = ancestor->m_parent) {
if (ancestor->used_values_per_layout_node[serial_id])
return *ancestor->used_values_per_layout_node[serial_id];
}
auto const* containing_block_used_values = box.is_initial_containing_block_box() ? nullptr : &get(*box.containing_block());
const_cast<LayoutState*>(this)->used_values_per_layout_node[serial_id] = adopt_own(*new UsedValues);
const_cast<LayoutState*>(this)->used_values_per_layout_node[serial_id]->set_node(const_cast<NodeWithStyleAndBoxModelMetrics&>(box), containing_block_used_values);
return *used_values_per_layout_node[serial_id];
}
void LayoutState::commit()
{
// Only the top-level LayoutState should ever be committed.
VERIFY(!m_parent);
HashTable<Layout::TextNode*> text_nodes;
for (auto& used_values_ptr : used_values_per_layout_node) {
if (!used_values_ptr)
continue;
auto& used_values = *used_values_ptr;
auto& node = const_cast<NodeWithStyleAndBoxModelMetrics&>(used_values.node());
// Transfer box model metrics.
node.box_model().inset = { used_values.inset_top, used_values.inset_right, used_values.inset_bottom, used_values.inset_left };
node.box_model().padding = { used_values.padding_top, used_values.padding_right, used_values.padding_bottom, used_values.padding_left };
node.box_model().border = { used_values.border_top, used_values.border_right, used_values.border_bottom, used_values.border_left };
node.box_model().margin = { used_values.margin_top, used_values.margin_right, used_values.margin_bottom, used_values.margin_left };
node.set_paintable(node.create_paintable());
// For boxes, transfer all the state needed for painting.
if (is<Layout::Box>(node)) {
auto& box = static_cast<Layout::Box const&>(node);
auto& paint_box = const_cast<Painting::PaintableBox&>(*box.paint_box());
paint_box.set_offset(used_values.offset);
paint_box.set_content_size(used_values.content_width(), used_values.content_height());
paint_box.set_overflow_data(move(used_values.overflow_data));
paint_box.set_containing_line_box_fragment(used_values.containing_line_box_fragment);
if (is<Layout::BlockContainer>(box)) {
for (auto& line_box : used_values.line_boxes) {
for (auto& fragment : line_box.fragments()) {
if (fragment.layout_node().is_text_node())
text_nodes.set(static_cast<Layout::TextNode*>(const_cast<Layout::Node*>(&fragment.layout_node())));
}
}
static_cast<Painting::PaintableWithLines&>(paint_box).set_line_boxes(move(used_values.line_boxes));
}
}
}
for (auto* text_node : text_nodes)
text_node->set_paintable(text_node->create_paintable());
}
Gfx::FloatRect margin_box_rect(Box const& box, LayoutState const& state)
{
auto const& box_state = state.get(box);
auto rect = Gfx::FloatRect { box_state.offset, { box_state.content_width(), box_state.content_height() } };
rect.set_x(rect.x() - box_state.margin_box_left());
rect.set_width(rect.width() + box_state.margin_box_left() + box_state.margin_box_right());
rect.set_y(rect.y() - box_state.margin_box_top());
rect.set_height(rect.height() + box_state.margin_box_top() + box_state.margin_box_bottom());
return rect;
}
Gfx::FloatRect border_box_rect(Box const& box, LayoutState const& state)
{
auto const& box_state = state.get(box);
auto rect = Gfx::FloatRect { box_state.offset, { box_state.content_width(), box_state.content_height() } };
rect.set_x(rect.x() - box_state.border_box_left());
rect.set_width(rect.width() + box_state.border_box_left() + box_state.border_box_right());
rect.set_y(rect.y() - box_state.border_box_top());
rect.set_height(rect.height() + box_state.border_box_top() + box_state.border_box_bottom());
return rect;
}
Gfx::FloatRect border_box_rect_in_ancestor_coordinate_space(Box const& box, Box const& ancestor_box, LayoutState const& state)
{
auto rect = border_box_rect(box, state);
for (auto const* current = box.parent(); current; current = current->parent()) {
if (current == &ancestor_box)
break;
if (is<Box>(*current)) {
auto const& current_state = state.get(static_cast<Box const&>(*current));
rect.translate_by(current_state.offset);
}
}
return rect;
}
Gfx::FloatRect content_box_rect(Box const& box, LayoutState const& state)
{
auto const& box_state = state.get(box);
return Gfx::FloatRect { box_state.offset, { box_state.content_width(), box_state.content_height() } };
}
Gfx::FloatRect content_box_rect_in_ancestor_coordinate_space(Box const& box, Box const& ancestor_box, LayoutState const& state)
{
auto rect = content_box_rect(box, state);
for (auto const* current = box.parent(); current; current = current->parent()) {
if (current == &ancestor_box)
break;
if (is<Box>(*current)) {
auto const& current_state = state.get(static_cast<Box const&>(*current));
rect.translate_by(current_state.offset);
}
}
return rect;
}
Gfx::FloatRect margin_box_rect_in_ancestor_coordinate_space(Box const& box, Box const& ancestor_box, LayoutState const& state)
{
auto rect = margin_box_rect(box, state);
for (auto const* current = box.parent(); current; current = current->parent()) {
if (current == &ancestor_box)
break;
if (is<Box>(*current)) {
auto const& current_state = state.get(static_cast<Box const&>(*current));
rect.translate_by(current_state.offset);
}
}
return rect;
}
Gfx::FloatRect absolute_content_rect(Box const& box, LayoutState const& state)
{
auto const& box_state = state.get(box);
Gfx::FloatRect rect { box_state.offset, { box_state.content_width(), box_state.content_height() } };
for (auto* block = box.containing_block(); block; block = block->containing_block())
rect.translate_by(state.get(*block).offset);
return rect;
}
void LayoutState::UsedValues::set_node(NodeWithStyleAndBoxModelMetrics& node, UsedValues const* containing_block_used_values)
{
m_node = &node;
auto const& computed_values = node.computed_values();
auto is_definite_size = [&](CSS::LengthPercentage const& size, float& resolved_definite_size, bool width) {
// A size that can be determined without performing layout; that is,
// a <length>,
// a measure of text (without consideration of line-wrapping),
// a size of the initial containing block,
// or a <percentage> or other formula (such as the “stretch-fit” sizing of non-replaced blocks [CSS2]) that is resolved solely against definite sizes.
auto containing_block_has_definite_size = containing_block_used_values ? (width ? containing_block_used_values->has_definite_width() : containing_block_used_values->has_definite_height()) : false;
if (size.is_auto()) {
// NOTE: The width of a non-flex-item block is considered definite if it's auto and the containing block has definite width.
if (width && node.parent() && !node.parent()->computed_values().display().is_flex_inside()) {
if (containing_block_has_definite_size) {
resolved_definite_size = width ? containing_block_used_values->content_width() : containing_block_used_values->content_height();
return true;
}
return false;
}
return false;
}
if (size.is_length()) {
resolved_definite_size = size.length().to_px(node);
return true;
}
if (size.is_percentage()) {
if (containing_block_has_definite_size) {
auto containing_block_size = width ? containing_block_used_values->content_width() : containing_block_used_values->content_height();
resolved_definite_size = containing_block_size * size.percentage().as_fraction();
return true;
}
return false;
}
// FIXME: Determine if calc() value is definite.
return false;
};
m_has_definite_width = is_definite_size(computed_values.width(), m_content_width, true);
m_has_definite_height = is_definite_size(computed_values.height(), m_content_height, false);
}
void LayoutState::UsedValues::set_content_width(float width)
{
m_content_width = width;
}
void LayoutState::UsedValues::set_content_height(float height)
{
m_content_height = height;
}
}