ecd3d0935a
It's not safe to hold on to a pointer to the cache slot across layout work, since the nested layout may end up causing new entries to get added to the cache, potentially invalidating a cache slot pointer.
1431 lines
68 KiB
C++
1431 lines
68 KiB
C++
/*
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* Copyright (c) 2020-2022, Andreas Kling <kling@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <LibWeb/Dump.h>
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#include <LibWeb/Layout/BlockFormattingContext.h>
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#include <LibWeb/Layout/Box.h>
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#include <LibWeb/Layout/FlexFormattingContext.h>
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#include <LibWeb/Layout/FormattingContext.h>
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#include <LibWeb/Layout/GridFormattingContext.h>
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#include <LibWeb/Layout/ReplacedBox.h>
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#include <LibWeb/Layout/SVGFormattingContext.h>
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#include <LibWeb/Layout/SVGSVGBox.h>
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#include <LibWeb/Layout/TableBox.h>
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#include <LibWeb/Layout/TableCellBox.h>
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#include <LibWeb/Layout/TableFormattingContext.h>
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#include <LibWeb/Layout/Viewport.h>
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namespace Web::Layout {
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FormattingContext::FormattingContext(Type type, LayoutState& state, Box const& context_box, FormattingContext* parent)
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: m_type(type)
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, m_parent(parent)
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, m_context_box(context_box)
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, m_state(state)
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{
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}
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FormattingContext::~FormattingContext() = default;
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// https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Block_formatting_context
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bool FormattingContext::creates_block_formatting_context(Box const& box)
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{
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// NOTE: Replaced elements never create a BFC.
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if (box.is_replaced_box())
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return false;
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// display: table
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if (box.display().is_table_inside()) {
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return false;
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}
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// display: flex
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if (box.display().is_flex_inside()) {
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return false;
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}
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// display: grid
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if (box.display().is_grid_inside()) {
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return false;
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}
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// NOTE: This function uses MDN as a reference, not because it's authoritative,
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// but because they've gathered all the conditions in one convenient location.
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// The root element of the document (<html>).
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if (box.is_root_element())
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return true;
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// Floats (elements where float isn't none).
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if (box.is_floating())
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return true;
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// Absolutely positioned elements (elements where position is absolute or fixed).
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if (box.is_absolutely_positioned())
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return true;
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// Inline-blocks (elements with display: inline-block).
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if (box.display().is_inline_block())
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return true;
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// Table cells (elements with display: table-cell, which is the default for HTML table cells).
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if (box.display().is_table_cell())
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return true;
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// Table captions (elements with display: table-caption, which is the default for HTML table captions).
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if (box.display().is_table_caption())
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return true;
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// FIXME: Anonymous table cells implicitly created by the elements with display: table, table-row, table-row-group, table-header-group, table-footer-group
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// (which is the default for HTML tables, table rows, table bodies, table headers, and table footers, respectively), or inline-table.
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// Block elements where overflow has a value other than visible and clip.
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CSS::Overflow overflow_x = box.computed_values().overflow_x();
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if ((overflow_x != CSS::Overflow::Visible) && (overflow_x != CSS::Overflow::Clip))
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return true;
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CSS::Overflow overflow_y = box.computed_values().overflow_y();
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if ((overflow_y != CSS::Overflow::Visible) && (overflow_y != CSS::Overflow::Clip))
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return true;
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// display: flow-root.
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if (box.display().is_flow_root_inside())
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return true;
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// FIXME: Elements with contain: layout, content, or paint.
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if (box.parent()) {
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auto parent_display = box.parent()->display();
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// Flex items (direct children of the element with display: flex or inline-flex) if they are neither flex nor grid nor table containers themselves.
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if (parent_display.is_flex_inside())
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return true;
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// Grid items (direct children of the element with display: grid or inline-grid) if they are neither flex nor grid nor table containers themselves.
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if (parent_display.is_grid_inside())
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return true;
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}
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// FIXME: Multicol containers (elements where column-count or column-width isn't auto, including elements with column-count: 1).
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// FIXME: column-span: all should always create a new formatting context, even when the column-span: all element isn't contained by a multicol container (Spec change, Chrome bug).
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return false;
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}
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Optional<FormattingContext::Type> FormattingContext::formatting_context_type_created_by_box(Box const& box)
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{
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if (box.is_replaced_box() && !box.can_have_children()) {
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return Type::InternalReplaced;
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}
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if (!box.can_have_children())
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return {};
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if (is<SVGSVGBox>(box))
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return Type::SVG;
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auto display = box.display();
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if (display.is_flex_inside())
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return Type::Flex;
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if (display.is_table_inside())
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return Type::Table;
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if (display.is_grid_inside())
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return Type::Grid;
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if (creates_block_formatting_context(box))
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return Type::Block;
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if (box.children_are_inline())
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return {};
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// The box is a block container that doesn't create its own BFC.
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// It will be formatted by the containing BFC.
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if (!display.is_flow_inside()) {
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// HACK: Instead of crashing, create a dummy formatting context that does nothing.
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// FIXME: Remove this once it's no longer needed. It currently swallows problem with standalone
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// table-related boxes that don't get fixed up by CSS anonymous table box generation.
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dbgln("FIXME: Child box doesn't create BFC, but inside is also not flow! display={}", MUST(display.to_string()));
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return Type::InternalDummy;
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}
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return {};
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}
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// FIXME: This is a hack. Get rid of it.
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struct ReplacedFormattingContext : public FormattingContext {
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ReplacedFormattingContext(LayoutState& state, Box const& box)
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: FormattingContext(Type::Block, state, box)
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{
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}
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virtual CSSPixels automatic_content_width() const override { return 0; }
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virtual CSSPixels automatic_content_height() const override { return 0; }
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virtual void run(Box const&, LayoutMode, AvailableSpace const&) override { }
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};
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// FIXME: This is a hack. Get rid of it.
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struct DummyFormattingContext : public FormattingContext {
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DummyFormattingContext(LayoutState& state, Box const& box)
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: FormattingContext(Type::Block, state, box)
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{
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}
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virtual CSSPixels automatic_content_width() const override { return 0; }
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virtual CSSPixels automatic_content_height() const override { return 0; }
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virtual void run(Box const&, LayoutMode, AvailableSpace const&) override { }
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};
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OwnPtr<FormattingContext> FormattingContext::create_independent_formatting_context_if_needed(LayoutState& state, Box const& child_box)
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{
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auto type = formatting_context_type_created_by_box(child_box);
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if (!type.has_value())
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return nullptr;
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switch (type.value()) {
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case Type::Block:
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return make<BlockFormattingContext>(state, verify_cast<BlockContainer>(child_box), this);
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case Type::SVG:
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return make<SVGFormattingContext>(state, child_box, this);
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case Type::Flex:
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return make<FlexFormattingContext>(state, child_box, this);
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case Type::Grid:
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return make<GridFormattingContext>(state, child_box, this);
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case Type::Table:
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return make<TableFormattingContext>(state, verify_cast<TableBox>(child_box), this);
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case Type::InternalReplaced:
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return make<ReplacedFormattingContext>(state, child_box);
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case Type::InternalDummy:
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return make<DummyFormattingContext>(state, child_box);
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case Type::Inline:
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// IFC should always be created by a parent BFC directly.
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VERIFY_NOT_REACHED();
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break;
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default:
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VERIFY_NOT_REACHED();
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}
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}
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OwnPtr<FormattingContext> FormattingContext::layout_inside(Box const& child_box, LayoutMode layout_mode, AvailableSpace const& available_space)
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{
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{
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// OPTIMIZATION: If we're doing intrinsic sizing and `child_box` has definite size in both axes,
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// we don't need to layout its insides. The size is resolvable without learning
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// the metrics of whatever's inside the box.
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auto const& used_values = m_state.get(child_box);
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if (layout_mode == LayoutMode::IntrinsicSizing
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&& used_values.width_constraint == SizeConstraint::None
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&& used_values.height_constraint == SizeConstraint::None
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&& used_values.has_definite_width()
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&& used_values.has_definite_height()) {
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return nullptr;
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}
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}
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if (!child_box.can_have_children())
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return {};
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auto independent_formatting_context = create_independent_formatting_context_if_needed(m_state, child_box);
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if (independent_formatting_context)
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independent_formatting_context->run(child_box, layout_mode, available_space);
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else
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run(child_box, layout_mode, available_space);
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return independent_formatting_context;
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}
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CSSPixels FormattingContext::greatest_child_width(Box const& box) const
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{
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CSSPixels max_width = 0;
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if (box.children_are_inline()) {
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for (auto& line_box : m_state.get(box).line_boxes) {
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max_width = max(max_width, line_box.width());
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}
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} else {
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box.for_each_child_of_type<Box>([&](Box const& child) {
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if (!child.is_absolutely_positioned())
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max_width = max(max_width, m_state.get(child).margin_box_width());
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});
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}
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return max_width;
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}
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FormattingContext::ShrinkToFitResult FormattingContext::calculate_shrink_to_fit_widths(Box const& box)
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{
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return {
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.preferred_width = calculate_max_content_width(box),
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.preferred_minimum_width = calculate_min_content_width(box),
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};
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}
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static CSSPixelSize solve_replaced_size_constraint(LayoutState const& state, CSSPixels w, CSSPixels h, ReplacedBox const& box)
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{
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// 10.4 Minimum and maximum widths: 'min-width' and 'max-width'
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auto const& containing_block = *box.containing_block();
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auto const& containing_block_state = state.get(containing_block);
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auto width_of_containing_block = CSS::Length::make_px(containing_block_state.content_width());
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auto height_of_containing_block = CSS::Length::make_px(containing_block_state.content_height());
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CSSPixels specified_min_width = box.computed_values().min_width().is_auto() ? 0 : box.computed_values().min_width().resolved(box, width_of_containing_block).to_px(box);
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CSSPixels specified_max_width = box.computed_values().max_width().is_none() ? w : box.computed_values().max_width().resolved(box, width_of_containing_block).to_px(box);
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CSSPixels specified_min_height = box.computed_values().min_height().is_auto() ? 0 : box.computed_values().min_height().resolved(box, height_of_containing_block).to_px(box);
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CSSPixels specified_max_height = box.computed_values().max_height().is_none() ? h : box.computed_values().max_height().resolved(box, height_of_containing_block).to_px(box);
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auto min_width = min(specified_min_width, specified_max_width);
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auto max_width = max(specified_min_width, specified_max_width);
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auto min_height = min(specified_min_height, specified_max_height);
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auto max_height = max(specified_min_height, specified_max_height);
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if (w > max_width)
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return { w, max(max_width * (h / w), min_height) };
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if (w < min_width)
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return { max_width, min(min_width * (h / w), max_height) };
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if (h > max_height)
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return { max(max_height * (w / h), min_width), max_height };
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if (h < min_height)
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return { min(min_height * (w / h), max_width), min_height };
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if ((w > max_width && h > max_height) && (max_width / w < max_height / h))
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return { max_width, max(min_height, max_width * (h / w)) };
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if ((w > max_width && h > max_height) && (max_width / w > max_height / h))
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return { max(min_width, max_height * (w / h)), max_height };
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if ((w < min_width && h < min_height) && (min_width / w < min_height / h))
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return { min(max_width, min_height * (w / h)), min_height };
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if ((w < min_width && h < min_height) && (min_width / w > min_height / h))
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return { min_width, min(max_height, min_width * (h / w)) };
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if (w < min_width && h > max_height)
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return { min_width, max_height };
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if (w > max_width && h < min_height)
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return { max_width, min_height };
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return { w, h };
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}
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// https://www.w3.org/TR/CSS22/visudet.html#root-height
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CSSPixels FormattingContext::compute_auto_height_for_block_formatting_context_root(Box const& root) const
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{
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// 10.6.7 'Auto' heights for block formatting context roots
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Optional<CSSPixels> top;
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Optional<CSSPixels> bottom;
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if (root.children_are_inline()) {
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// If it only has inline-level children, the height is the distance between
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// the top content edge and the bottom of the bottommost line box.
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auto const& line_boxes = m_state.get(root).line_boxes;
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top = 0;
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if (!line_boxes.is_empty())
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bottom = line_boxes.last().bottom();
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} else {
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// If it has block-level children, the height is the distance between
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// the top margin-edge of the topmost block-level child box
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// and the bottom margin-edge of the bottommost block-level child box.
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root.for_each_child_of_type<Box>([&](Layout::Box& child_box) {
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// Absolutely positioned children are ignored,
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// and relatively positioned boxes are considered without their offset.
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// Note that the child box may be an anonymous block box.
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if (child_box.is_absolutely_positioned())
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return IterationDecision::Continue;
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// FIXME: This doesn't look right.
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if ((root.computed_values().overflow_y() == CSS::Overflow::Visible) && child_box.is_floating())
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return IterationDecision::Continue;
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auto const& child_box_state = m_state.get(child_box);
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CSSPixels child_box_top = child_box_state.offset.y() - child_box_state.margin_box_top();
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CSSPixels child_box_bottom = child_box_state.offset.y() + child_box_state.content_height() + child_box_state.margin_box_bottom();
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if (!top.has_value() || child_box_top < top.value())
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top = child_box_top;
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if (!bottom.has_value() || child_box_bottom > bottom.value())
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bottom = child_box_bottom;
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return IterationDecision::Continue;
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});
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}
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// In addition, if the element has any floating descendants
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// whose bottom margin edge is below the element's bottom content edge,
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// then the height is increased to include those edges.
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for (auto floating_box : m_state.get(root).floating_descendants()) {
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// NOTE: Floating box coordinates are relative to their own containing block,
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// which may or may not be the BFC root.
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auto margin_box = margin_box_rect_in_ancestor_coordinate_space(*floating_box, root, m_state);
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CSSPixels floating_box_bottom_margin_edge = margin_box.bottom() + 1;
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if (!bottom.has_value() || floating_box_bottom_margin_edge > bottom.value())
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bottom = floating_box_bottom_margin_edge;
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}
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return max(CSSPixels(0.0f), bottom.value_or(0) - top.value_or(0));
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}
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// 10.3.2 Inline, replaced elements, https://www.w3.org/TR/CSS22/visudet.html#inline-replaced-width
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CSSPixels FormattingContext::tentative_width_for_replaced_element(LayoutState const& state, ReplacedBox const& box, CSS::Size const& computed_width, AvailableSpace const& available_space)
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{
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// Treat percentages of indefinite containing block widths as 0 (the initial width).
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if (computed_width.is_percentage() && !state.get(*box.containing_block()).has_definite_width())
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return 0;
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auto height_of_containing_block = CSS::Length::make_px(containing_block_height_for(box, state));
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auto computed_height = should_treat_height_as_auto(box, available_space) ? CSS::Size::make_auto() : box.computed_values().height();
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CSSPixels used_width = computed_width.resolved(box, CSS::Length::make_px(available_space.width.to_px())).to_px(box);
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// If 'height' and 'width' both have computed values of 'auto' and the element also has an intrinsic width,
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// then that intrinsic width is the used value of 'width'.
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if (computed_height.is_auto() && computed_width.is_auto() && box.has_intrinsic_width())
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return box.intrinsic_width().value();
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// If 'height' and 'width' both have computed values of 'auto' and the element has no intrinsic width,
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// but does have an intrinsic height and intrinsic ratio;
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// or if 'width' has a computed value of 'auto',
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// 'height' has some other computed value, and the element does have an intrinsic ratio; then the used value of 'width' is:
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//
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// (used height) * (intrinsic ratio)
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if ((computed_height.is_auto() && computed_width.is_auto() && !box.has_intrinsic_width() && box.has_intrinsic_height() && box.has_intrinsic_aspect_ratio())
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|| (computed_width.is_auto() && !computed_height.is_auto() && box.has_intrinsic_aspect_ratio())) {
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return compute_height_for_replaced_element(state, box, available_space) * box.intrinsic_aspect_ratio().value();
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}
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// If 'height' and 'width' both have computed values of 'auto' and the element has an intrinsic ratio but no intrinsic height or width,
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// then the used value of 'width' is undefined in CSS 2.2. However, it is suggested that, if the containing block's width does not itself
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// depend on the replaced element's width, then the used value of 'width' is calculated from the constraint equation used for block-level,
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// non-replaced elements in normal flow.
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// Otherwise, if 'width' has a computed value of 'auto', and the element has an intrinsic width, then that intrinsic width is the used value of 'width'.
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if (computed_width.is_auto() && box.has_intrinsic_width())
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return box.intrinsic_width().value();
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// Otherwise, if 'width' has a computed value of 'auto', but none of the conditions above are met, then the used value of 'width' becomes 300px.
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// If 300px is too wide to fit the device, UAs should use the width of the largest rectangle that has a 2:1 ratio and fits the device instead.
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if (computed_width.is_auto())
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return 300;
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return used_width;
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}
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void FormattingContext::compute_width_for_absolutely_positioned_element(Box const& box, AvailableSpace const& available_space)
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{
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if (is<ReplacedBox>(box))
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compute_width_for_absolutely_positioned_replaced_element(verify_cast<ReplacedBox>(box), available_space);
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else
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compute_width_for_absolutely_positioned_non_replaced_element(box, available_space);
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}
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void FormattingContext::compute_height_for_absolutely_positioned_element(Box const& box, AvailableSpace const& available_space, BeforeOrAfterInsideLayout before_or_after_inside_layout)
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{
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if (is<ReplacedBox>(box))
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compute_height_for_absolutely_positioned_replaced_element(static_cast<ReplacedBox const&>(box), available_space, before_or_after_inside_layout);
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else
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compute_height_for_absolutely_positioned_non_replaced_element(box, available_space, before_or_after_inside_layout);
|
|
}
|
|
|
|
CSSPixels FormattingContext::compute_width_for_replaced_element(LayoutState const& state, ReplacedBox const& box, AvailableSpace const& available_space)
|
|
{
|
|
// 10.3.4 Block-level, replaced elements in normal flow...
|
|
// 10.3.2 Inline, replaced elements
|
|
|
|
auto zero_value = CSS::Length::make_px(0);
|
|
auto width_of_containing_block_as_length = CSS::Length::make_px(available_space.width.to_px());
|
|
|
|
auto margin_left = box.computed_values().margin().left().resolved(box, width_of_containing_block_as_length).resolved(box);
|
|
auto margin_right = box.computed_values().margin().right().resolved(box, width_of_containing_block_as_length).resolved(box);
|
|
|
|
// A computed value of 'auto' for 'margin-left' or 'margin-right' becomes a used value of '0'.
|
|
if (margin_left.is_auto())
|
|
margin_left = zero_value;
|
|
if (margin_right.is_auto())
|
|
margin_right = zero_value;
|
|
|
|
auto computed_width = should_treat_width_as_auto(box, available_space) ? CSS::Size::make_auto() : box.computed_values().width();
|
|
|
|
// 1. The tentative used width is calculated (without 'min-width' and 'max-width')
|
|
auto used_width = tentative_width_for_replaced_element(state, box, computed_width, available_space);
|
|
|
|
// 2. The tentative used width is greater than 'max-width', the rules above are applied again,
|
|
// but this time using the computed value of 'max-width' as the computed value for 'width'.
|
|
auto computed_max_width = box.computed_values().max_width();
|
|
if (!computed_max_width.is_none()) {
|
|
if (used_width > computed_max_width.resolved(box, width_of_containing_block_as_length).to_px(box)) {
|
|
used_width = tentative_width_for_replaced_element(state, box, computed_max_width, available_space);
|
|
}
|
|
}
|
|
|
|
// 3. If the resulting width is smaller than 'min-width', the rules above are applied again,
|
|
// but this time using the value of 'min-width' as the computed value for 'width'.
|
|
auto computed_min_width = box.computed_values().min_width();
|
|
if (!computed_min_width.is_auto()) {
|
|
if (used_width < computed_min_width.resolved(box, width_of_containing_block_as_length).to_px(box)) {
|
|
used_width = tentative_width_for_replaced_element(state, box, computed_min_width, available_space);
|
|
}
|
|
}
|
|
|
|
return used_width;
|
|
}
|
|
|
|
// 10.6.2 Inline replaced elements, block-level replaced elements in normal flow, 'inline-block' replaced elements in normal flow and floating replaced elements
|
|
// https://www.w3.org/TR/CSS22/visudet.html#inline-replaced-height
|
|
CSSPixels FormattingContext::tentative_height_for_replaced_element(LayoutState const& state, ReplacedBox const& box, CSS::Size const& computed_height, AvailableSpace const& available_space)
|
|
{
|
|
// If 'height' and 'width' both have computed values of 'auto' and the element also has
|
|
// an intrinsic height, then that intrinsic height is the used value of 'height'.
|
|
if (should_treat_width_as_auto(box, available_space) && should_treat_height_as_auto(box, available_space) && box.has_intrinsic_height())
|
|
return box.intrinsic_height().value();
|
|
|
|
// Otherwise, if 'height' has a computed value of 'auto', and the element has an intrinsic ratio then the used value of 'height' is:
|
|
//
|
|
// (used width) / (intrinsic ratio)
|
|
if (computed_height.is_auto() && box.has_intrinsic_aspect_ratio())
|
|
return compute_width_for_replaced_element(state, box, available_space) / box.intrinsic_aspect_ratio().value();
|
|
|
|
// Otherwise, if 'height' has a computed value of 'auto', and the element has an intrinsic height, then that intrinsic height is the used value of 'height'.
|
|
if (computed_height.is_auto() && box.has_intrinsic_height())
|
|
return box.intrinsic_height().value();
|
|
|
|
// Otherwise, if 'height' has a computed value of 'auto', but none of the conditions above are met,
|
|
// then the used value of 'height' must be set to the height of the largest rectangle that has a 2:1 ratio, has a height not greater than 150px,
|
|
// and has a width not greater than the device width.
|
|
if (computed_height.is_auto())
|
|
return 150;
|
|
|
|
return computed_height.resolved(box, CSS::Length::make_px(available_space.height.to_px())).to_px(box);
|
|
}
|
|
|
|
CSSPixels FormattingContext::compute_height_for_replaced_element(LayoutState const& state, ReplacedBox const& box, AvailableSpace const& available_space)
|
|
{
|
|
// 10.6.2 Inline replaced elements, block-level replaced elements in normal flow,
|
|
// 'inline-block' replaced elements in normal flow and floating replaced elements
|
|
|
|
auto width_of_containing_block_as_length = CSS::Length::make_px(available_space.width.to_px());
|
|
auto height_of_containing_block_as_length = CSS::Length::make_px(available_space.height.to_px());
|
|
auto computed_width = should_treat_width_as_auto(box, available_space) ? CSS::Size::make_auto() : box.computed_values().width();
|
|
auto computed_height = should_treat_height_as_auto(box, available_space) ? CSS::Size::make_auto() : box.computed_values().height();
|
|
|
|
CSSPixels used_height = tentative_height_for_replaced_element(state, box, computed_height, available_space);
|
|
|
|
if (computed_width.is_auto() && computed_height.is_auto() && box.has_intrinsic_aspect_ratio()) {
|
|
CSSPixels w = tentative_width_for_replaced_element(state, box, computed_width, available_space);
|
|
CSSPixels h = used_height;
|
|
used_height = solve_replaced_size_constraint(state, w, h, box).height();
|
|
}
|
|
|
|
return used_height;
|
|
}
|
|
|
|
void FormattingContext::compute_width_for_absolutely_positioned_non_replaced_element(Box const& box, AvailableSpace const& available_space)
|
|
{
|
|
auto width_of_containing_block = available_space.width.to_px();
|
|
auto width_of_containing_block_as_length = CSS::Length::make_px(width_of_containing_block);
|
|
auto& computed_values = box.computed_values();
|
|
auto zero_value = CSS::Length::make_px(0);
|
|
|
|
auto margin_left = CSS::Length::make_auto();
|
|
auto margin_right = CSS::Length::make_auto();
|
|
auto const border_left = computed_values.border_left().width;
|
|
auto const border_right = computed_values.border_right().width;
|
|
auto const padding_left = computed_values.padding().left().resolved(box, width_of_containing_block_as_length).to_px(box);
|
|
auto const padding_right = computed_values.padding().right().resolved(box, width_of_containing_block_as_length).to_px(box);
|
|
|
|
auto try_compute_width = [&](auto const& a_width) {
|
|
margin_left = computed_values.margin().left().resolved(box, width_of_containing_block_as_length).resolved(box);
|
|
margin_right = computed_values.margin().right().resolved(box, width_of_containing_block_as_length).resolved(box);
|
|
|
|
auto left = computed_values.inset().left().resolved(box, width_of_containing_block_as_length).resolved(box);
|
|
auto right = computed_values.inset().right().resolved(box, width_of_containing_block_as_length).resolved(box);
|
|
auto width = a_width;
|
|
|
|
auto solve_for_left = [&] {
|
|
return CSS::Length::make_px(width_of_containing_block - margin_left.to_px(box) - border_left - padding_left - width.to_px(box) - padding_right - border_right - margin_right.to_px(box) - right.to_px(box));
|
|
};
|
|
|
|
auto solve_for_width = [&] {
|
|
return CSS::Length::make_px(max(CSSPixels(0), width_of_containing_block - left.to_px(box) - margin_left.to_px(box) - border_left - padding_left - padding_right - border_right - margin_right.to_px(box) - right.to_px(box)));
|
|
};
|
|
|
|
auto solve_for_right = [&] {
|
|
return CSS::Length::make_px(width_of_containing_block - left.to_px(box) - margin_left.to_px(box) - border_left - padding_left - width.to_px(box) - padding_right - border_right - margin_right.to_px(box));
|
|
};
|
|
|
|
// If all three of 'left', 'width', and 'right' are 'auto':
|
|
if (left.is_auto() && width.is_auto() && right.is_auto()) {
|
|
// First set any 'auto' values for 'margin-left' and 'margin-right' to 0.
|
|
if (margin_left.is_auto())
|
|
margin_left = CSS::Length::make_px(0);
|
|
if (margin_right.is_auto())
|
|
margin_right = CSS::Length::make_px(0);
|
|
// Then, if the 'direction' property of the element establishing the static-position containing block
|
|
// is 'ltr' set 'left' to the static position and apply rule number three below;
|
|
// otherwise, set 'right' to the static position and apply rule number one below.
|
|
// FIXME: This is very hackish.
|
|
left = CSS::Length::make_px(0);
|
|
goto Rule3;
|
|
}
|
|
|
|
if (!left.is_auto() && !width.is_auto() && !right.is_auto()) {
|
|
// FIXME: This should be solved in a more complicated way.
|
|
return width;
|
|
}
|
|
|
|
if (margin_left.is_auto())
|
|
margin_left = CSS::Length::make_px(0);
|
|
if (margin_right.is_auto())
|
|
margin_right = CSS::Length::make_px(0);
|
|
|
|
// 1. 'left' and 'width' are 'auto' and 'right' is not 'auto',
|
|
// then the width is shrink-to-fit. Then solve for 'left'
|
|
if (left.is_auto() && width.is_auto() && !right.is_auto()) {
|
|
auto result = calculate_shrink_to_fit_widths(box);
|
|
auto available_width = solve_for_width();
|
|
width = CSS::Length::make_px(min(max(result.preferred_minimum_width, available_width.to_px(box)), result.preferred_width));
|
|
left = solve_for_left();
|
|
}
|
|
|
|
// 2. 'left' and 'right' are 'auto' and 'width' is not 'auto',
|
|
// then if the 'direction' property of the element establishing
|
|
// the static-position containing block is 'ltr' set 'left'
|
|
// to the static position, otherwise set 'right' to the static position.
|
|
// Then solve for 'left' (if 'direction is 'rtl') or 'right' (if 'direction' is 'ltr').
|
|
else if (left.is_auto() && right.is_auto() && !width.is_auto()) {
|
|
// FIXME: Check direction
|
|
// FIXME: Use the static-position containing block
|
|
left = zero_value;
|
|
right = solve_for_right();
|
|
}
|
|
|
|
// 3. 'width' and 'right' are 'auto' and 'left' is not 'auto',
|
|
// then the width is shrink-to-fit. Then solve for 'right'
|
|
else if (width.is_auto() && right.is_auto() && !left.is_auto()) {
|
|
Rule3:
|
|
auto result = calculate_shrink_to_fit_widths(box);
|
|
auto available_width = solve_for_width();
|
|
width = CSS::Length::make_px(min(max(result.preferred_minimum_width, available_width.to_px(box)), result.preferred_width));
|
|
right = solve_for_right();
|
|
}
|
|
|
|
// 4. 'left' is 'auto', 'width' and 'right' are not 'auto', then solve for 'left'
|
|
else if (left.is_auto() && !width.is_auto() && !right.is_auto()) {
|
|
left = solve_for_left();
|
|
}
|
|
|
|
// 5. 'width' is 'auto', 'left' and 'right' are not 'auto', then solve for 'width'
|
|
else if (width.is_auto() && !left.is_auto() && !right.is_auto()) {
|
|
width = solve_for_width();
|
|
}
|
|
|
|
// 6. 'right' is 'auto', 'left' and 'width' are not 'auto', then solve for 'right'
|
|
else if (right.is_auto() && !left.is_auto() && !width.is_auto()) {
|
|
right = solve_for_right();
|
|
}
|
|
|
|
return width;
|
|
};
|
|
|
|
// 1. The tentative used width is calculated (without 'min-width' and 'max-width')
|
|
auto used_width = try_compute_width(calculate_inner_width(box, available_space.width, computed_values.width()));
|
|
|
|
// 2. The tentative used width is greater than 'max-width', the rules above are applied again,
|
|
// but this time using the computed value of 'max-width' as the computed value for 'width'.
|
|
if (!computed_values.max_width().is_none()) {
|
|
auto max_width = calculate_inner_width(box, available_space.width, computed_values.max_width());
|
|
if (used_width.to_px(box) > max_width.to_px(box)) {
|
|
used_width = try_compute_width(max_width);
|
|
}
|
|
}
|
|
|
|
// 3. If the resulting width is smaller than 'min-width', the rules above are applied again,
|
|
// but this time using the value of 'min-width' as the computed value for 'width'.
|
|
if (!computed_values.min_width().is_auto()) {
|
|
auto min_width = calculate_inner_width(box, available_space.width, computed_values.min_width());
|
|
if (used_width.to_px(box) < min_width.to_px(box)) {
|
|
used_width = try_compute_width(min_width);
|
|
}
|
|
}
|
|
|
|
auto& box_state = m_state.get_mutable(box);
|
|
box_state.set_content_width(used_width.to_px(box));
|
|
|
|
box_state.margin_left = margin_left.to_px(box);
|
|
box_state.margin_right = margin_right.to_px(box);
|
|
box_state.border_left = border_left;
|
|
box_state.border_right = border_right;
|
|
box_state.padding_left = padding_left;
|
|
box_state.padding_right = padding_right;
|
|
}
|
|
|
|
void FormattingContext::compute_width_for_absolutely_positioned_replaced_element(ReplacedBox const& box, AvailableSpace const& available_space)
|
|
{
|
|
// 10.3.8 Absolutely positioned, replaced elements
|
|
// The used value of 'width' is determined as for inline replaced elements.
|
|
// FIXME: This const_cast is gross.
|
|
const_cast<ReplacedBox&>(box).prepare_for_replaced_layout();
|
|
m_state.get_mutable(box).set_content_width(compute_width_for_replaced_element(m_state, box, available_space));
|
|
}
|
|
|
|
// https://drafts.csswg.org/css-position-3/#abs-non-replaced-height
|
|
void FormattingContext::compute_height_for_absolutely_positioned_non_replaced_element(Box const& box, AvailableSpace const& available_space, BeforeOrAfterInsideLayout before_or_after_inside_layout)
|
|
{
|
|
// 5.3. The Height Of Absolutely Positioned, Non-Replaced Elements
|
|
|
|
// For absolutely positioned elements, the used values of the vertical dimensions must satisfy this constraint:
|
|
// top + margin-top + border-top-width + padding-top + height + padding-bottom + border-bottom-width + margin-bottom + bottom = height of containing block
|
|
|
|
// NOTE: This function is called twice: both before and after inside layout.
|
|
// In the before pass, if it turns out we need the automatic height of the box, we abort these steps.
|
|
// This allows the box to retain an indefinite height from the perspective of inside layout.
|
|
|
|
auto margin_top = box.computed_values().margin().top();
|
|
auto margin_bottom = box.computed_values().margin().bottom();
|
|
auto top = box.computed_values().inset().top();
|
|
auto bottom = box.computed_values().inset().bottom();
|
|
auto height = box.computed_values().height();
|
|
|
|
auto width_of_containing_block = containing_block_width_for(box);
|
|
auto width_of_containing_block_as_length = CSS::Length::make_px(width_of_containing_block);
|
|
auto height_of_containing_block = available_space.height.to_px();
|
|
auto height_of_containing_block_as_length = CSS::Length::make_px(height_of_containing_block);
|
|
|
|
enum class ClampToZero {
|
|
No,
|
|
Yes,
|
|
};
|
|
auto solve_for = [&](CSS::Length length, ClampToZero clamp_to_zero = ClampToZero::No) {
|
|
auto unclamped_value = height_of_containing_block
|
|
- top.resolved(box, height_of_containing_block_as_length).to_px(box)
|
|
- margin_top.resolved(box, width_of_containing_block_as_length).to_px(box)
|
|
- box.computed_values().border_top().width
|
|
- box.computed_values().padding().top().resolved(box, width_of_containing_block_as_length).to_px(box)
|
|
- height.resolved(box, height_of_containing_block_as_length).to_px(box)
|
|
- box.computed_values().padding().bottom().resolved(box, width_of_containing_block_as_length).to_px(box)
|
|
- box.computed_values().border_bottom().width
|
|
- margin_bottom.resolved(box, width_of_containing_block_as_length).to_px(box)
|
|
- bottom.resolved(box, height_of_containing_block_as_length).to_px(box)
|
|
+ length.to_px(box);
|
|
if (clamp_to_zero == ClampToZero::Yes)
|
|
return CSS::Length::make_px(max(CSSPixels(0), unclamped_value));
|
|
return CSS::Length::make_px(unclamped_value);
|
|
};
|
|
|
|
auto solve_for_top = [&] {
|
|
top = solve_for(top.resolved(box, height_of_containing_block_as_length));
|
|
};
|
|
|
|
auto solve_for_bottom = [&] {
|
|
bottom = solve_for(bottom.resolved(box, height_of_containing_block_as_length));
|
|
};
|
|
|
|
auto solve_for_height = [&] {
|
|
height = CSS::Size::make_length(solve_for(height.resolved(box, height_of_containing_block_as_length), ClampToZero::Yes));
|
|
};
|
|
|
|
auto solve_for_margin_top = [&] {
|
|
margin_top = solve_for(margin_top.resolved(box, width_of_containing_block_as_length));
|
|
};
|
|
|
|
auto solve_for_margin_bottom = [&] {
|
|
margin_bottom = solve_for(margin_bottom.resolved(box, width_of_containing_block_as_length));
|
|
};
|
|
|
|
auto solve_for_margin_top_and_margin_bottom = [&] {
|
|
auto remainder = solve_for(CSS::Length::make_px(margin_top.resolved(box, width_of_containing_block_as_length).to_px(box) + margin_bottom.resolved(box, width_of_containing_block_as_length).to_px(box))).to_px(box);
|
|
margin_top = CSS::Length::make_px(remainder / 2);
|
|
margin_bottom = CSS::Length::make_px(remainder / 2);
|
|
};
|
|
|
|
// If all three of top, height, and bottom are auto:
|
|
if (top.is_auto() && height.is_auto() && bottom.is_auto()) {
|
|
// (If we haven't done inside layout yet, we can't compute the auto height.)
|
|
if (before_or_after_inside_layout == BeforeOrAfterInsideLayout::Before)
|
|
return;
|
|
|
|
// First set any auto values for margin-top and margin-bottom to 0,
|
|
if (margin_top.is_auto())
|
|
margin_top = CSS::Length::make_px(0);
|
|
if (margin_bottom.is_auto())
|
|
margin_bottom = CSS::Length::make_px(0);
|
|
|
|
// then set top to the static position,
|
|
auto static_position = calculate_static_position(box);
|
|
top = CSS::Length::make_px(static_position.y());
|
|
|
|
// and finally apply rule number three below.
|
|
height = CSS::Size::make_px(compute_auto_height_for_block_formatting_context_root(box));
|
|
solve_for_bottom();
|
|
}
|
|
|
|
// If none of the three are auto:
|
|
else if (!top.is_auto() && !height.is_auto() && !bottom.is_auto()) {
|
|
// If both margin-top and margin-bottom are auto,
|
|
if (margin_top.is_auto() && margin_bottom.is_auto()) {
|
|
// solve the equation under the extra constraint that the two margins get equal values.
|
|
solve_for_margin_top_and_margin_bottom();
|
|
}
|
|
|
|
// If one of margin-top or margin-bottom is auto,
|
|
else if (margin_top.is_auto() || margin_bottom.is_auto()) {
|
|
// solve the equation for that value.
|
|
if (margin_top.is_auto())
|
|
solve_for_margin_top();
|
|
else
|
|
solve_for_margin_bottom();
|
|
}
|
|
|
|
// If the values are over-constrained,
|
|
else {
|
|
// ignore the value for bottom and solve for that value.
|
|
solve_for_bottom();
|
|
}
|
|
}
|
|
|
|
// Otherwise,
|
|
else {
|
|
// set auto values for margin-top and margin-bottom to 0,
|
|
if (margin_top.is_auto())
|
|
margin_top = CSS::Length::make_px(0);
|
|
if (margin_bottom.is_auto())
|
|
margin_bottom = CSS::Length::make_px(0);
|
|
|
|
// and pick one of the following six rules that apply.
|
|
|
|
// 1. If top and height are auto and bottom is not auto,
|
|
if (top.is_auto() && height.is_auto() && !bottom.is_auto()) {
|
|
// (If we haven't done inside layout yet, we can't compute the auto height.)
|
|
if (before_or_after_inside_layout == BeforeOrAfterInsideLayout::Before)
|
|
return;
|
|
|
|
// then the height is based on the Auto heights for block formatting context roots,
|
|
height = CSS::Size::make_px(compute_auto_height_for_block_formatting_context_root(box));
|
|
|
|
// and solve for top.
|
|
solve_for_top();
|
|
}
|
|
|
|
// 2. If top and bottom are auto and height is not auto,
|
|
else if (top.is_auto() && bottom.is_auto() && !height.is_auto()) {
|
|
// then set top to the static position,
|
|
top = CSS::Length::make_px(calculate_static_position(box).y());
|
|
|
|
// then solve for bottom.
|
|
solve_for_bottom();
|
|
}
|
|
|
|
// 3. If height and bottom are auto and top is not auto,
|
|
else if (height.is_auto() && bottom.is_auto() && !top.is_auto()) {
|
|
// (If we haven't done inside layout yet, we can't compute the auto height.)
|
|
if (before_or_after_inside_layout == BeforeOrAfterInsideLayout::Before)
|
|
return;
|
|
|
|
// then the height is based on the Auto heights for block formatting context roots,
|
|
height = CSS::Size::make_px(compute_auto_height_for_block_formatting_context_root(box));
|
|
|
|
// and solve for bottom.
|
|
solve_for_bottom();
|
|
}
|
|
|
|
// 4. If top is auto, height and bottom are not auto,
|
|
else if (top.is_auto() && !height.is_auto() && !bottom.is_auto()) {
|
|
// then solve for top.
|
|
solve_for_top();
|
|
}
|
|
|
|
// 5. If height is auto, top and bottom are not auto,
|
|
else if (height.is_auto() && !top.is_auto() && !bottom.is_auto()) {
|
|
// then solve for height.
|
|
solve_for_height();
|
|
}
|
|
|
|
// 6. If bottom is auto, top and height are not auto,
|
|
else if (bottom.is_auto() && !top.is_auto() && !height.is_auto()) {
|
|
// then solve for bottom.
|
|
solve_for_bottom();
|
|
}
|
|
}
|
|
|
|
auto used_height = height.resolved(box, height_of_containing_block_as_length).to_px(box);
|
|
auto const& computed_min_height = box.computed_values().min_height();
|
|
auto const& computed_max_height = box.computed_values().max_height();
|
|
|
|
if (!computed_max_height.is_none())
|
|
used_height = min(used_height, computed_max_height.resolved(box, height_of_containing_block_as_length).resolved(box).to_px(box));
|
|
if (!computed_min_height.is_auto())
|
|
used_height = max(used_height, computed_min_height.resolved(box, height_of_containing_block_as_length).resolved(box).to_px(box));
|
|
|
|
// NOTE: The following is not directly part of any spec, but this is where we resolve
|
|
// the final used values for vertical margin/border/padding.
|
|
|
|
auto& box_state = m_state.get_mutable(box);
|
|
box_state.margin_top = margin_top.resolved(box, width_of_containing_block_as_length).to_px(box);
|
|
box_state.margin_bottom = margin_bottom.resolved(box, width_of_containing_block_as_length).to_px(box);
|
|
box_state.border_top = box.computed_values().border_top().width;
|
|
box_state.border_bottom = box.computed_values().border_bottom().width;
|
|
box_state.padding_top = box.computed_values().padding().top().resolved(box, width_of_containing_block_as_length).to_px(box);
|
|
box_state.padding_bottom = box.computed_values().padding().bottom().resolved(box, width_of_containing_block_as_length).to_px(box);
|
|
|
|
// And here is where we assign the box's content height.
|
|
box_state.set_content_height(used_height);
|
|
}
|
|
|
|
// NOTE: This is different from content_box_rect_in_ancestor_coordinate_space() as this does *not* follow the containing block chain up, but rather the parent() chain.
|
|
static CSSPixelRect content_box_rect_in_static_position_ancestor_coordinate_space(Box const& box, Box const& ancestor_box, LayoutState const& state)
|
|
{
|
|
auto rect = content_box_rect(box, state);
|
|
if (&box == &ancestor_box)
|
|
return rect;
|
|
for (auto const* current = box.parent(); current; current = current->parent()) {
|
|
if (current == &ancestor_box)
|
|
return rect;
|
|
auto const& current_state = state.get(static_cast<Box const&>(*current));
|
|
rect.translate_by(current_state.offset);
|
|
}
|
|
// If we get here, ancestor_box was not an ancestor of `box`!
|
|
VERIFY_NOT_REACHED();
|
|
}
|
|
|
|
// https://www.w3.org/TR/css-position-3/#staticpos-rect
|
|
CSSPixelPoint FormattingContext::calculate_static_position(Box const& box) const
|
|
{
|
|
// NOTE: This is very ad-hoc.
|
|
// The purpose of this function is to calculate the approximate position that `box`
|
|
// would have had if it were position:static.
|
|
|
|
CSSPixels x = 0.0f;
|
|
CSSPixels y = 0.0f;
|
|
|
|
VERIFY(box.parent());
|
|
if (box.parent()->children_are_inline()) {
|
|
// We're an abspos box with inline siblings. This is gonna get messy!
|
|
if (auto* sibling = box.previous_sibling()) {
|
|
// Hard case: there's a previous sibling. This means there's already inline content
|
|
// preceding the hypothetical static position of `box` within its containing block.
|
|
// If we had been position:static, that inline content would have been wrapped in
|
|
// anonymous block box, so now we get to imagine what the world might have looked like
|
|
// in that scenario..
|
|
// Basically, we find its last associated line box fragment and place `box` under it.
|
|
// FIXME: I'm 100% sure this can be smarter, better and faster.
|
|
LineBoxFragment const* last_fragment = nullptr;
|
|
auto& cb_state = m_state.get(*sibling->containing_block());
|
|
for (auto& line_box : cb_state.line_boxes) {
|
|
for (auto& fragment : line_box.fragments()) {
|
|
if (&fragment.layout_node() == sibling)
|
|
last_fragment = &fragment;
|
|
}
|
|
}
|
|
if (last_fragment) {
|
|
y = (last_fragment->offset().y() + last_fragment->height()).value();
|
|
}
|
|
} else {
|
|
// Easy case: no previous sibling, we're at the top of the containing block.
|
|
}
|
|
} else {
|
|
x = m_state.get(box).margin_box_left();
|
|
// We're among block siblings, Y can be calculated easily.
|
|
y = m_state.get(box).margin_box_top();
|
|
}
|
|
auto offset_to_static_parent = content_box_rect_in_static_position_ancestor_coordinate_space(box, *box.containing_block(), m_state);
|
|
return offset_to_static_parent.location().translated(x, y);
|
|
}
|
|
|
|
void FormattingContext::layout_absolutely_positioned_element(Box const& box, AvailableSpace const& available_space)
|
|
{
|
|
auto& containing_block_state = m_state.get_mutable(*box.containing_block());
|
|
auto& box_state = m_state.get_mutable(box);
|
|
|
|
auto width_of_containing_block = available_space.width.to_px();
|
|
auto height_of_containing_block = available_space.height.to_px();
|
|
auto width_of_containing_block_as_length = CSS::Length::make_px(width_of_containing_block);
|
|
auto height_of_containing_block_as_length = CSS::Length::make_px(height_of_containing_block);
|
|
|
|
auto specified_width = box.computed_values().width().resolved(box, width_of_containing_block_as_length).resolved(box);
|
|
|
|
compute_width_for_absolutely_positioned_element(box, available_space);
|
|
|
|
// NOTE: We compute height before *and* after doing inside layout.
|
|
// This is done so that inside layout can resolve percentage heights.
|
|
// In some situations, e.g with non-auto top & bottom values, the height can be determined early.
|
|
compute_height_for_absolutely_positioned_element(box, available_space, BeforeOrAfterInsideLayout::Before);
|
|
|
|
auto independent_formatting_context = layout_inside(box, LayoutMode::Normal, box_state.available_inner_space_or_constraints_from(available_space));
|
|
|
|
compute_height_for_absolutely_positioned_element(box, available_space, BeforeOrAfterInsideLayout::After);
|
|
|
|
box_state.margin_left = box.computed_values().margin().left().resolved(box, width_of_containing_block_as_length).to_px(box);
|
|
box_state.margin_top = box.computed_values().margin().top().resolved(box, width_of_containing_block_as_length).to_px(box);
|
|
box_state.margin_right = box.computed_values().margin().right().resolved(box, width_of_containing_block_as_length).to_px(box);
|
|
box_state.margin_bottom = box.computed_values().margin().bottom().resolved(box, width_of_containing_block_as_length).to_px(box);
|
|
|
|
box_state.border_left = box.computed_values().border_left().width;
|
|
box_state.border_right = box.computed_values().border_right().width;
|
|
box_state.border_top = box.computed_values().border_top().width;
|
|
box_state.border_bottom = box.computed_values().border_bottom().width;
|
|
|
|
auto const& computed_left = box.computed_values().inset().left();
|
|
auto const& computed_right = box.computed_values().inset().right();
|
|
auto const& computed_top = box.computed_values().inset().top();
|
|
auto const& computed_bottom = box.computed_values().inset().bottom();
|
|
|
|
box_state.inset_left = computed_left.resolved(box, width_of_containing_block_as_length).to_px(box);
|
|
box_state.inset_top = computed_top.resolved(box, height_of_containing_block_as_length).to_px(box);
|
|
box_state.inset_right = computed_right.resolved(box, width_of_containing_block_as_length).to_px(box);
|
|
box_state.inset_bottom = computed_bottom.resolved(box, height_of_containing_block_as_length).to_px(box);
|
|
|
|
if (computed_left.is_auto() && box.computed_values().width().is_auto() && computed_right.is_auto()) {
|
|
if (box.computed_values().margin().left().is_auto())
|
|
box_state.margin_left = 0;
|
|
if (box.computed_values().margin().right().is_auto())
|
|
box_state.margin_right = 0;
|
|
}
|
|
|
|
auto static_position = calculate_static_position(box);
|
|
|
|
CSSPixelPoint used_offset;
|
|
|
|
if (!computed_left.is_auto()) {
|
|
CSSPixels x_offset = box_state.inset_left
|
|
+ box_state.border_box_left();
|
|
used_offset.set_x(x_offset + box_state.margin_left);
|
|
} else if (!computed_right.is_auto()) {
|
|
CSSPixels x_offset = CSSPixels(0)
|
|
- box_state.inset_right
|
|
- box_state.border_box_right();
|
|
used_offset.set_x(width_of_containing_block + x_offset - box_state.content_width() - box_state.margin_right);
|
|
} else {
|
|
// NOTE: static position is content box position so border_box and margin should not be added
|
|
used_offset.set_x(static_position.x());
|
|
}
|
|
|
|
if (!computed_top.is_auto()) {
|
|
CSSPixels y_offset = box_state.inset_top
|
|
+ box_state.border_box_top();
|
|
used_offset.set_y(y_offset + box_state.margin_top);
|
|
} else if (!computed_bottom.is_auto()) {
|
|
CSSPixels y_offset = CSSPixels(0)
|
|
- box_state.inset_bottom
|
|
- box_state.border_box_bottom();
|
|
used_offset.set_y(height_of_containing_block + y_offset - box_state.content_height() - box_state.margin_bottom);
|
|
} else {
|
|
// NOTE: static position is content box position so border_box and margin should not be added
|
|
used_offset.set_y(static_position.y());
|
|
}
|
|
|
|
// NOTE: Absolutely positioned boxes are relative to the *padding edge* of the containing block.
|
|
used_offset.translate_by(-containing_block_state.padding_left, -containing_block_state.padding_top);
|
|
|
|
box_state.set_content_offset(used_offset);
|
|
|
|
if (independent_formatting_context)
|
|
independent_formatting_context->parent_context_did_dimension_child_root_box();
|
|
}
|
|
|
|
void FormattingContext::compute_height_for_absolutely_positioned_replaced_element(ReplacedBox const& box, AvailableSpace const& available_space, BeforeOrAfterInsideLayout)
|
|
{
|
|
// 10.6.5 Absolutely positioned, replaced elements
|
|
// The used value of 'height' is determined as for inline replaced elements.
|
|
m_state.get_mutable(box).set_content_height(compute_height_for_replaced_element(m_state, box, available_space));
|
|
}
|
|
|
|
// https://www.w3.org/TR/css-position-3/#relpos-insets
|
|
void FormattingContext::compute_inset(Box const& box)
|
|
{
|
|
if (box.computed_values().position() != CSS::Position::Relative)
|
|
return;
|
|
|
|
auto resolve_two_opposing_insets = [&](CSS::LengthPercentage const& computed_start, CSS::LengthPercentage const& computed_end, CSSPixels& used_start, CSSPixels& used_end, CSSPixels reference_for_percentage) {
|
|
auto resolved_first = computed_start.resolved(box, CSS::Length::make_px(reference_for_percentage)).resolved(box);
|
|
auto resolved_second = computed_end.resolved(box, CSS::Length::make_px(reference_for_percentage)).resolved(box);
|
|
|
|
if (resolved_first.is_auto() && resolved_second.is_auto()) {
|
|
// If opposing inset properties in an axis both compute to auto (their initial values),
|
|
// their used values are zero (i.e., the boxes stay in their original position in that axis).
|
|
used_start = 0;
|
|
used_end = 0;
|
|
} else if (resolved_first.is_auto() || resolved_second.is_auto()) {
|
|
// If only one is auto, its used value becomes the negation of the other, and the box is shifted by the specified amount.
|
|
if (resolved_first.is_auto()) {
|
|
used_end = resolved_second.to_px(box);
|
|
used_start = -used_end;
|
|
} else {
|
|
used_start = resolved_first.to_px(box);
|
|
used_end = -used_start;
|
|
}
|
|
} else {
|
|
// If neither is auto, the position is over-constrained; (with respect to the writing mode of its containing block)
|
|
// the computed end side value is ignored, and its used value becomes the negation of the start side.
|
|
used_start = resolved_first.to_px(box);
|
|
used_end = -used_start;
|
|
}
|
|
};
|
|
|
|
auto& box_state = m_state.get_mutable(box);
|
|
auto const& computed_values = box.computed_values();
|
|
|
|
// FIXME: Respect the containing block's writing-mode.
|
|
resolve_two_opposing_insets(computed_values.inset().left(), computed_values.inset().right(), box_state.inset_left, box_state.inset_right, containing_block_width_for(box));
|
|
resolve_two_opposing_insets(computed_values.inset().top(), computed_values.inset().bottom(), box_state.inset_top, box_state.inset_bottom, containing_block_height_for(box));
|
|
}
|
|
|
|
// https://drafts.csswg.org/css-sizing-3/#fit-content-size
|
|
CSSPixels FormattingContext::calculate_fit_content_width(Layout::Box const& box, AvailableSpace const& available_space) const
|
|
{
|
|
// If the available space in a given axis is definite,
|
|
// equal to clamp(min-content size, stretch-fit size, max-content size)
|
|
// (i.e. max(min-content size, min(max-content size, stretch-fit size))).
|
|
if (available_space.width.is_definite()) {
|
|
return max(calculate_min_content_width(box),
|
|
min(calculate_stretch_fit_width(box, available_space.width),
|
|
calculate_max_content_width(box)));
|
|
}
|
|
|
|
// When sizing under a min-content constraint, equal to the min-content size.
|
|
if (available_space.width.is_min_content())
|
|
return calculate_min_content_width(box);
|
|
|
|
// Otherwise, equal to the max-content size in that axis.
|
|
return calculate_max_content_width(box);
|
|
}
|
|
|
|
// https://drafts.csswg.org/css-sizing-3/#fit-content-size
|
|
CSSPixels FormattingContext::calculate_fit_content_height(Layout::Box const& box, AvailableSpace const& available_space) const
|
|
{
|
|
// If the available space in a given axis is definite,
|
|
// equal to clamp(min-content size, stretch-fit size, max-content size)
|
|
// (i.e. max(min-content size, min(max-content size, stretch-fit size))).
|
|
if (available_space.height.is_definite()) {
|
|
return max(calculate_min_content_height(box, available_space.width),
|
|
min(calculate_stretch_fit_height(box, available_space.height),
|
|
calculate_max_content_height(box, available_space.width)));
|
|
}
|
|
|
|
// When sizing under a min-content constraint, equal to the min-content size.
|
|
if (available_space.height.is_min_content())
|
|
return calculate_min_content_height(box, available_space.width);
|
|
|
|
// Otherwise, equal to the max-content size in that axis.
|
|
return calculate_max_content_height(box, available_space.width);
|
|
}
|
|
|
|
CSSPixels FormattingContext::calculate_min_content_width(Layout::Box const& box) const
|
|
{
|
|
if (box.has_intrinsic_width())
|
|
return *box.intrinsic_width();
|
|
|
|
auto& root_state = m_state.m_root;
|
|
|
|
auto& cache = *root_state.intrinsic_sizes.ensure(&box, [] { return adopt_own(*new LayoutState::IntrinsicSizes); });
|
|
if (cache.min_content_width.has_value())
|
|
return *cache.min_content_width;
|
|
|
|
LayoutState throwaway_state(&m_state);
|
|
|
|
auto& box_state = throwaway_state.get_mutable(box);
|
|
box_state.width_constraint = SizeConstraint::MinContent;
|
|
box_state.set_indefinite_content_width();
|
|
box_state.set_indefinite_content_height();
|
|
|
|
auto context = const_cast<FormattingContext*>(this)->create_independent_formatting_context_if_needed(throwaway_state, box);
|
|
VERIFY(context);
|
|
|
|
auto available_width = AvailableSize::make_min_content();
|
|
auto available_height = AvailableSize::make_indefinite();
|
|
context->run(box, LayoutMode::IntrinsicSizing, AvailableSpace(available_width, available_height));
|
|
|
|
cache.min_content_width = context->automatic_content_width();
|
|
|
|
if (!isfinite(cache.min_content_width->value())) {
|
|
// HACK: If layout calculates a non-finite result, something went wrong. Force it to zero and log a little whine.
|
|
dbgln("FIXME: Calculated non-finite min-content width for {}", box.debug_description());
|
|
cache.min_content_width = 0;
|
|
}
|
|
|
|
return *cache.min_content_width;
|
|
}
|
|
|
|
CSSPixels FormattingContext::calculate_max_content_width(Layout::Box const& box) const
|
|
{
|
|
if (box.has_intrinsic_width())
|
|
return *box.intrinsic_width();
|
|
|
|
auto& root_state = m_state.m_root;
|
|
|
|
auto& cache = *root_state.intrinsic_sizes.ensure(&box, [] { return adopt_own(*new LayoutState::IntrinsicSizes); });
|
|
if (cache.max_content_width.has_value())
|
|
return *cache.max_content_width;
|
|
|
|
LayoutState throwaway_state(&m_state);
|
|
|
|
auto& box_state = throwaway_state.get_mutable(box);
|
|
box_state.width_constraint = SizeConstraint::MaxContent;
|
|
box_state.set_indefinite_content_width();
|
|
box_state.set_indefinite_content_height();
|
|
|
|
auto context = const_cast<FormattingContext*>(this)->create_independent_formatting_context_if_needed(throwaway_state, box);
|
|
VERIFY(context);
|
|
|
|
auto available_width = AvailableSize::make_max_content();
|
|
auto available_height = AvailableSize::make_indefinite();
|
|
context->run(box, LayoutMode::IntrinsicSizing, AvailableSpace(available_width, available_height));
|
|
|
|
cache.max_content_width = context->automatic_content_width();
|
|
|
|
if (!isfinite(cache.max_content_width->value())) {
|
|
// HACK: If layout calculates a non-finite result, something went wrong. Force it to zero and log a little whine.
|
|
dbgln("FIXME: Calculated non-finite max-content width for {}", box.debug_description());
|
|
cache.max_content_width = 0;
|
|
}
|
|
|
|
return *cache.max_content_width;
|
|
}
|
|
|
|
// https://www.w3.org/TR/css-sizing-3/#min-content-block-size
|
|
CSSPixels FormattingContext::calculate_min_content_height(Layout::Box const& box, AvailableSize const& available_width) const
|
|
{
|
|
// For block containers, tables, and inline boxes, this is equivalent to the max-content block size.
|
|
if (box.is_block_container() || box.is_table())
|
|
return calculate_max_content_height(box, available_width);
|
|
|
|
if (box.has_intrinsic_height())
|
|
return *box.intrinsic_height();
|
|
|
|
bool is_cacheable = available_width.is_definite() || available_width.is_intrinsic_sizing_constraint();
|
|
|
|
auto get_cache_slot = [&]() -> Optional<CSSPixels>* {
|
|
if (!is_cacheable)
|
|
return {};
|
|
auto& root_state = m_state.m_root;
|
|
auto& cache = *root_state.intrinsic_sizes.ensure(&box, [] { return adopt_own(*new LayoutState::IntrinsicSizes); });
|
|
if (available_width.is_definite())
|
|
return &cache.min_content_height_with_definite_available_width.ensure(available_width.to_px());
|
|
if (available_width.is_min_content())
|
|
return &cache.min_content_height_with_min_content_available_width;
|
|
if (available_width.is_max_content())
|
|
return &cache.min_content_height_with_max_content_available_width;
|
|
return {};
|
|
};
|
|
|
|
if (auto* cache_slot = get_cache_slot(); cache_slot && cache_slot->has_value())
|
|
return cache_slot->value();
|
|
|
|
LayoutState throwaway_state(&m_state);
|
|
|
|
auto& box_state = throwaway_state.get_mutable(box);
|
|
box_state.height_constraint = SizeConstraint::MinContent;
|
|
box_state.set_indefinite_content_height();
|
|
if (available_width.is_definite())
|
|
box_state.set_content_width(available_width.to_px());
|
|
|
|
auto context = const_cast<FormattingContext*>(this)->create_independent_formatting_context_if_needed(throwaway_state, box);
|
|
VERIFY(context);
|
|
|
|
context->run(box, LayoutMode::IntrinsicSizing, AvailableSpace(available_width, AvailableSize::make_min_content()));
|
|
|
|
auto min_content_height = context->automatic_content_height();
|
|
if (!isfinite(min_content_height.value())) {
|
|
// HACK: If layout calculates a non-finite result, something went wrong. Force it to zero and log a little whine.
|
|
dbgln("FIXME: Calculated non-finite min-content height for {}", box.debug_description());
|
|
min_content_height = 0;
|
|
}
|
|
|
|
if (auto* cache_slot = get_cache_slot()) {
|
|
*cache_slot = min_content_height;
|
|
}
|
|
return min_content_height;
|
|
}
|
|
|
|
CSSPixels FormattingContext::calculate_max_content_height(Layout::Box const& box, AvailableSize const& available_width) const
|
|
{
|
|
if (box.has_intrinsic_aspect_ratio() && available_width.is_definite())
|
|
return available_width.to_px() / *box.intrinsic_aspect_ratio();
|
|
|
|
if (box.has_intrinsic_height())
|
|
return *box.intrinsic_height();
|
|
|
|
bool is_cacheable = available_width.is_definite() || available_width.is_intrinsic_sizing_constraint();
|
|
|
|
auto get_cache_slot = [&]() -> Optional<CSSPixels>* {
|
|
if (!is_cacheable)
|
|
return {};
|
|
auto& root_state = m_state.m_root;
|
|
auto& cache = *root_state.intrinsic_sizes.ensure(&box, [] { return adopt_own(*new LayoutState::IntrinsicSizes); });
|
|
if (available_width.is_definite())
|
|
return &cache.max_content_height_with_definite_available_width.ensure(available_width.to_px());
|
|
if (available_width.is_min_content())
|
|
return &cache.max_content_height_with_min_content_available_width;
|
|
if (available_width.is_max_content())
|
|
return &cache.max_content_height_with_max_content_available_width;
|
|
return {};
|
|
};
|
|
|
|
if (auto* cache_slot = get_cache_slot(); cache_slot && cache_slot->has_value())
|
|
return cache_slot->value();
|
|
|
|
LayoutState throwaway_state(&m_state);
|
|
|
|
auto& box_state = throwaway_state.get_mutable(box);
|
|
box_state.height_constraint = SizeConstraint::MaxContent;
|
|
box_state.set_indefinite_content_height();
|
|
if (available_width.is_definite())
|
|
box_state.set_content_width(available_width.to_px());
|
|
|
|
auto context = const_cast<FormattingContext*>(this)->create_independent_formatting_context_if_needed(throwaway_state, box);
|
|
VERIFY(context);
|
|
|
|
context->run(box, LayoutMode::IntrinsicSizing, AvailableSpace(available_width, AvailableSize::make_max_content()));
|
|
|
|
auto max_content_height = context->automatic_content_height();
|
|
|
|
if (!isfinite(max_content_height.value())) {
|
|
// HACK: If layout calculates a non-finite result, something went wrong. Force it to zero and log a little whine.
|
|
dbgln("FIXME: Calculated non-finite max-content height for {}", box.debug_description());
|
|
max_content_height = 0;
|
|
}
|
|
|
|
if (auto* cache_slot = get_cache_slot()) {
|
|
*cache_slot = max_content_height;
|
|
}
|
|
|
|
return max_content_height;
|
|
}
|
|
|
|
CSS::Length FormattingContext::calculate_inner_width(Layout::Box const& box, AvailableSize const& available_width, CSS::Size const& width) const
|
|
{
|
|
auto width_of_containing_block = available_width.to_px();
|
|
auto width_of_containing_block_as_length_for_resolve = CSS::Length::make_px(width_of_containing_block);
|
|
if (width.is_auto()) {
|
|
return width.resolved(box, width_of_containing_block_as_length_for_resolve).resolved(box);
|
|
}
|
|
|
|
auto& computed_values = box.computed_values();
|
|
if (computed_values.box_sizing() == CSS::BoxSizing::BorderBox) {
|
|
auto const padding_left = computed_values.padding().left().resolved(box, width_of_containing_block_as_length_for_resolve);
|
|
auto const padding_right = computed_values.padding().right().resolved(box, width_of_containing_block_as_length_for_resolve);
|
|
|
|
auto inner_width = width.resolved(box, width_of_containing_block_as_length_for_resolve).to_px(box)
|
|
- computed_values.border_left().width
|
|
- padding_left.to_px(box)
|
|
- computed_values.border_right().width
|
|
- padding_right.to_px(box);
|
|
return CSS::Length::make_px(max(inner_width, 0));
|
|
}
|
|
|
|
return width.resolved(box, width_of_containing_block_as_length_for_resolve).resolved(box);
|
|
}
|
|
|
|
CSS::Length FormattingContext::calculate_inner_height(Layout::Box const& box, AvailableSize const& available_height, CSS::Size const& height) const
|
|
{
|
|
auto height_of_containing_block = available_height.to_px();
|
|
auto height_of_containing_block_as_length_for_resolve = CSS::Length::make_px(height_of_containing_block);
|
|
if (height.is_auto()) {
|
|
return height.resolved(box, height_of_containing_block_as_length_for_resolve).resolved(box);
|
|
}
|
|
|
|
auto& computed_values = box.computed_values();
|
|
if (computed_values.box_sizing() == CSS::BoxSizing::BorderBox) {
|
|
auto width_of_containing_block = CSS::Length::make_px(containing_block_width_for(box));
|
|
|
|
auto const padding_top = computed_values.padding().top().resolved(box, width_of_containing_block);
|
|
auto const padding_bottom = computed_values.padding().bottom().resolved(box, width_of_containing_block);
|
|
|
|
auto inner_height = height.resolved(box, height_of_containing_block_as_length_for_resolve).to_px(box)
|
|
- computed_values.border_top().width
|
|
- padding_top.to_px(box)
|
|
- computed_values.border_bottom().width
|
|
- padding_bottom.to_px(box);
|
|
return CSS::Length::make_px(max(inner_height, 0));
|
|
}
|
|
|
|
return height.resolved(box, height_of_containing_block_as_length_for_resolve).resolved(box);
|
|
}
|
|
|
|
CSSPixels FormattingContext::containing_block_width_for(Box const& box, LayoutState const& state)
|
|
{
|
|
auto& containing_block_state = state.get(*box.containing_block());
|
|
auto& box_state = state.get(box);
|
|
|
|
switch (box_state.width_constraint) {
|
|
case SizeConstraint::MinContent:
|
|
return 0;
|
|
case SizeConstraint::MaxContent:
|
|
return INFINITY;
|
|
case SizeConstraint::None:
|
|
return containing_block_state.content_width();
|
|
}
|
|
VERIFY_NOT_REACHED();
|
|
}
|
|
|
|
CSSPixels FormattingContext::containing_block_height_for(Box const& box, LayoutState const& state)
|
|
{
|
|
auto& containing_block_state = state.get(*box.containing_block());
|
|
auto& box_state = state.get(box);
|
|
|
|
switch (box_state.height_constraint) {
|
|
case SizeConstraint::MinContent:
|
|
return 0;
|
|
case SizeConstraint::MaxContent:
|
|
return INFINITY;
|
|
case SizeConstraint::None:
|
|
return containing_block_state.content_height();
|
|
}
|
|
VERIFY_NOT_REACHED();
|
|
}
|
|
|
|
// https://drafts.csswg.org/css-sizing-3/#stretch-fit-size
|
|
CSSPixels FormattingContext::calculate_stretch_fit_width(Box const& box, AvailableSize const& available_width) const
|
|
{
|
|
// The size a box would take if its outer size filled the available space in the given axis;
|
|
// in other words, the stretch fit into the available space, if that is definite.
|
|
// Undefined if the available space is indefinite.
|
|
auto const& box_state = m_state.get(box);
|
|
return available_width.to_px()
|
|
- box_state.margin_left
|
|
- box_state.margin_right
|
|
- box_state.padding_left
|
|
- box_state.padding_right
|
|
- box_state.border_left
|
|
- box_state.border_right;
|
|
}
|
|
|
|
// https://drafts.csswg.org/css-sizing-3/#stretch-fit-size
|
|
CSSPixels FormattingContext::calculate_stretch_fit_height(Box const& box, AvailableSize const& available_height) const
|
|
{
|
|
// The size a box would take if its outer size filled the available space in the given axis;
|
|
// in other words, the stretch fit into the available space, if that is definite.
|
|
// Undefined if the available space is indefinite.
|
|
auto const& box_state = m_state.get(box);
|
|
return available_height.to_px()
|
|
- box_state.margin_top
|
|
- box_state.margin_bottom
|
|
- box_state.padding_top
|
|
- box_state.padding_bottom
|
|
- box_state.border_top
|
|
- box_state.border_bottom;
|
|
}
|
|
|
|
bool FormattingContext::should_treat_width_as_auto(Box const& box, AvailableSpace const& available_space)
|
|
{
|
|
return box.computed_values().width().is_auto()
|
|
|| (box.computed_values().width().contains_percentage() && !available_space.width.is_definite());
|
|
}
|
|
|
|
bool FormattingContext::should_treat_height_as_auto(Box const& box, AvailableSpace const& available_space)
|
|
{
|
|
return box.computed_values().height().is_auto()
|
|
|| (box.computed_values().height().contains_percentage() && !available_space.height.is_definite());
|
|
}
|
|
|
|
bool FormattingContext::can_skip_is_anonymous_text_run(Box& box)
|
|
{
|
|
if (box.is_anonymous() && !box.is_generated() && !box.first_child_of_type<BlockContainer>()) {
|
|
bool contains_only_white_space = true;
|
|
box.for_each_in_subtree([&](auto const& node) {
|
|
if (!is<TextNode>(node) || !static_cast<TextNode const&>(node).dom_node().data().is_whitespace()) {
|
|
contains_only_white_space = false;
|
|
return IterationDecision::Break;
|
|
}
|
|
return IterationDecision::Continue;
|
|
});
|
|
if (contains_only_white_space)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
}
|