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

201 lines
8.6 KiB
C++

/*
* Copyright (c) 2022, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/HashMap.h>
#include <LibGfx/Point.h>
#include <LibWeb/Layout/Box.h>
#include <LibWeb/Layout/LineBox.h>
#include <LibWeb/Painting/PaintableBox.h>
#include <LibWeb/Painting/SVGGraphicsPaintable.h>
namespace Web::Layout {
enum class SizeConstraint {
None,
MinContent,
MaxContent,
};
class AvailableSize;
class AvailableSpace;
struct LayoutState {
LayoutState()
: m_root(*this)
{
}
explicit LayoutState(LayoutState const* parent);
~LayoutState();
LayoutState const& find_root() const
{
LayoutState const* root = this;
for (auto* state = m_parent; state; state = state->m_parent)
root = state;
return *root;
}
struct UsedValues {
NodeWithStyle const& node() const { return *m_node; }
void set_node(NodeWithStyle&, UsedValues const* containing_block_used_values);
UsedValues const* containing_block_used_values() const { return m_containing_block_used_values; }
CSSPixels content_width() const { return m_content_width; }
CSSPixels content_height() const { return m_content_height; }
void set_content_width(CSSPixels);
void set_content_height(CSSPixels);
void set_indefinite_content_width();
void set_indefinite_content_height();
void set_has_definite_width(bool has_definite_width) { m_has_definite_width = has_definite_width; }
void set_has_definite_height(bool has_definite_height) { m_has_definite_height = has_definite_height; }
// NOTE: These are used by FlexFormattingContext to assign a temporary main size to items
// early on, so that descendants have something to resolve percentages against.
void set_temporary_content_width(CSSPixels);
void set_temporary_content_height(CSSPixels);
bool has_definite_width() const { return m_has_definite_width && width_constraint == SizeConstraint::None; }
bool has_definite_height() const { return m_has_definite_height && height_constraint == SizeConstraint::None; }
// Returns the available space for content inside this layout box.
// If the space in an axis is indefinite, and the outer space is an intrinsic sizing constraint,
// the constraint is used in that axis instead.
AvailableSpace available_inner_space_or_constraints_from(AvailableSpace const& outer_space) const;
void set_content_offset(CSSPixelPoint);
void set_content_x(CSSPixels);
void set_content_y(CSSPixels);
CSSPixelPoint offset;
SizeConstraint width_constraint { SizeConstraint::None };
SizeConstraint height_constraint { SizeConstraint::None };
CSSPixels margin_left { 0 };
CSSPixels margin_right { 0 };
CSSPixels margin_top { 0 };
CSSPixels margin_bottom { 0 };
CSSPixels border_left { 0 };
CSSPixels border_right { 0 };
CSSPixels border_top { 0 };
CSSPixels border_bottom { 0 };
CSSPixels padding_left { 0 };
CSSPixels padding_right { 0 };
CSSPixels padding_top { 0 };
CSSPixels padding_bottom { 0 };
CSSPixels inset_left { 0 };
CSSPixels inset_right { 0 };
CSSPixels inset_top { 0 };
CSSPixels inset_bottom { 0 };
// Used for calculating the static position of an abspos block-level box.
CSSPixels vertical_offset_of_parent_block_container { 0 };
Vector<LineBox> line_boxes;
CSSPixels margin_box_left() const { return margin_left + border_left_collapsed() + padding_left; }
CSSPixels margin_box_right() const { return margin_right + border_right_collapsed() + padding_right; }
CSSPixels margin_box_top() const { return margin_top + border_top_collapsed() + padding_top; }
CSSPixels margin_box_bottom() const { return margin_bottom + border_bottom_collapsed() + padding_bottom; }
CSSPixels margin_box_width() const { return margin_box_left() + content_width() + margin_box_right(); }
CSSPixels margin_box_height() const { return margin_box_top() + content_height() + margin_box_bottom(); }
CSSPixels border_box_left() const { return border_left_collapsed() + padding_left; }
CSSPixels border_box_right() const { return border_right_collapsed() + padding_right; }
CSSPixels border_box_top() const { return border_top_collapsed() + padding_top; }
CSSPixels border_box_bottom() const { return border_bottom_collapsed() + padding_bottom; }
CSSPixels border_box_width() const { return border_box_left() + content_width() + border_box_right(); }
CSSPixels border_box_height() const { return border_box_top() + content_height() + border_box_bottom(); }
Optional<LineBoxFragmentCoordinate> containing_line_box_fragment;
void add_floating_descendant(Box const& box) { m_floating_descendants.set(&box); }
auto const& floating_descendants() const { return m_floating_descendants; }
void set_override_borders_data(Painting::PaintableBox::BordersDataWithElementKind const& override_borders_data) { m_override_borders_data = override_borders_data; }
auto const& override_borders_data() const { return m_override_borders_data; }
void set_table_cell_coordinates(Painting::PaintableBox::TableCellCoordinates const& table_cell_coordinates) { m_table_cell_coordinates = table_cell_coordinates; }
auto const& table_cell_coordinates() const { return m_table_cell_coordinates; }
void set_computed_svg_path(Gfx::Path const& svg_path) { m_computed_svg_path = svg_path; }
auto& computed_svg_path() { return m_computed_svg_path; }
void set_computed_svg_transforms(Painting::SVGGraphicsPaintable::ComputedTransforms const& computed_transforms) { m_computed_svg_transforms = computed_transforms; }
auto const& computed_svg_transforms() const { return m_computed_svg_transforms; }
private:
AvailableSize available_width_inside() const;
AvailableSize available_height_inside() const;
bool use_collapsing_borders_model() const { return m_override_borders_data.has_value(); }
// Implement the collapsing border model https://www.w3.org/TR/CSS22/tables.html#collapsing-borders.
CSSPixels border_left_collapsed() const { return use_collapsing_borders_model() ? round(border_left / 2) : border_left; }
CSSPixels border_right_collapsed() const { return use_collapsing_borders_model() ? round(border_right / 2) : border_right; }
CSSPixels border_top_collapsed() const { return use_collapsing_borders_model() ? round(border_top / 2) : border_top; }
CSSPixels border_bottom_collapsed() const { return use_collapsing_borders_model() ? round(border_bottom / 2) : border_bottom; }
JS::GCPtr<Layout::NodeWithStyle> m_node { nullptr };
UsedValues const* m_containing_block_used_values { nullptr };
CSSPixels m_content_width { 0 };
CSSPixels m_content_height { 0 };
bool m_has_definite_width { false };
bool m_has_definite_height { false };
HashTable<JS::GCPtr<Box const>> m_floating_descendants;
Optional<Painting::PaintableBox::BordersDataWithElementKind> m_override_borders_data;
Optional<Painting::PaintableBox::TableCellCoordinates> m_table_cell_coordinates;
Optional<Gfx::Path> m_computed_svg_path;
Optional<Painting::SVGGraphicsPaintable::ComputedTransforms> m_computed_svg_transforms;
};
// Commits the used values produced by layout and builds a paintable tree.
void commit(Box& root);
// NOTE: get_mutable() will CoW the UsedValues if it's inherited from an ancestor state;
UsedValues& get_mutable(NodeWithStyle const&);
// NOTE: get() will not CoW the UsedValues.
UsedValues const& get(NodeWithStyle const&) const;
HashMap<Layout::Node const*, NonnullOwnPtr<UsedValues>> used_values_per_layout_node;
// We cache intrinsic sizes once determined, as they will not change over the course of a full layout.
// This avoids computing them several times while performing flex layout.
struct IntrinsicSizes {
Optional<CSSPixels> min_content_width;
Optional<CSSPixels> max_content_width;
HashMap<CSSPixels, Optional<CSSPixels>> min_content_height;
HashMap<CSSPixels, Optional<CSSPixels>> max_content_height;
};
HashMap<JS::GCPtr<NodeWithStyle const>, NonnullOwnPtr<IntrinsicSizes>> mutable intrinsic_sizes;
LayoutState const* m_parent { nullptr };
LayoutState const& m_root;
private:
void resolve_relative_positions();
};
}