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

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/*
* Copyright (c) 2022, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibWeb/Layout/InlineFormattingContext.h>
namespace Web::Layout {
class LineBuilder {
AK_MAKE_NONCOPYABLE(LineBuilder);
AK_MAKE_NONMOVABLE(LineBuilder);
public:
LineBuilder(InlineFormattingContext&, LayoutState&);
~LineBuilder();
void break_line(Optional<float> next_item_width = {});
void append_box(Box const&, float leading_size, float trailing_size, float leading_margin, float trailing_margin);
void append_text_chunk(TextNode const&, size_t offset_in_node, size_t length_in_node, float leading_size, float trailing_size, float leading_margin, float trailing_margin, float content_width, float content_height);
// Returns whether a line break occurred.
LibWeb: Express intrinsic size layout via size constraints Previously, we had three layout modes: - Normal: - Everything uses the computed values from CSS. - MinContent: - Containing blocks act as if they have 0 width. - All line breaking opportunities are taken. - MaxContent: - Containing blocks act as if they have infinite width. - Only forced line breaks are accepted. The above was based on a set of misunderstandings of CSS sizing. A major problem with the above was that *all* containing blocks behaved differently during intrinsic size layout, not just the relevant one. With this patch there are only two layout modes: - Normal: - Everything uses the computed values from CSS. - IntrinsicSizeDetermination: - One or more boxes have size constraints applied. There are two size constraints per layout box, set here: - FormattingState::NodeState::width_constraint - FormattingState::NodeState::height_constraint They are of type SizeConstraint and can be one of None, MinContent, or MaxContent. The default is None. When performing an IntrinsicSizeDetermination layout, we now assign a size constraint to the box we're trying to determine the intrinsic size of, which is then honored by using two new helpers to query the dimensions of containing blocks: - FormattingContext::containing_block_width_for(Box) - FormattingContext::containing_block_height_for(Box) If there's a relevant constraint in effect on the Box, the size of its containing block is adjusted accordingly. This is essentially an implementation of the "available space" constraints from CSS-SIZING-3. I'm sure some things will break from this, and we'll have to deal with that separately. Spec: https://drafts.csswg.org/css-sizing-3/#available
2022-07-09 16:17:47 +03:00
bool break_if_needed(float next_item_width)
{
LibWeb: Express intrinsic size layout via size constraints Previously, we had three layout modes: - Normal: - Everything uses the computed values from CSS. - MinContent: - Containing blocks act as if they have 0 width. - All line breaking opportunities are taken. - MaxContent: - Containing blocks act as if they have infinite width. - Only forced line breaks are accepted. The above was based on a set of misunderstandings of CSS sizing. A major problem with the above was that *all* containing blocks behaved differently during intrinsic size layout, not just the relevant one. With this patch there are only two layout modes: - Normal: - Everything uses the computed values from CSS. - IntrinsicSizeDetermination: - One or more boxes have size constraints applied. There are two size constraints per layout box, set here: - FormattingState::NodeState::width_constraint - FormattingState::NodeState::height_constraint They are of type SizeConstraint and can be one of None, MinContent, or MaxContent. The default is None. When performing an IntrinsicSizeDetermination layout, we now assign a size constraint to the box we're trying to determine the intrinsic size of, which is then honored by using two new helpers to query the dimensions of containing blocks: - FormattingContext::containing_block_width_for(Box) - FormattingContext::containing_block_height_for(Box) If there's a relevant constraint in effect on the Box, the size of its containing block is adjusted accordingly. This is essentially an implementation of the "available space" constraints from CSS-SIZING-3. I'm sure some things will break from this, and we'll have to deal with that separately. Spec: https://drafts.csswg.org/css-sizing-3/#available
2022-07-09 16:17:47 +03:00
if (should_break(next_item_width)) {
break_line(next_item_width);
return true;
}
return false;
}
float available_width_for_current_line() const { return m_available_width_for_current_line; }
void update_last_line();
void remove_last_line_if_empty();
float current_y() const { return m_current_y; }
void set_current_y(float y) { m_current_y = y; }
void recalculate_available_space();
float y_for_float_to_be_inserted_here(Box const&);
private:
void begin_new_line(bool increment_y, bool is_first_break_in_sequence = true);
LibWeb: Express intrinsic size layout via size constraints Previously, we had three layout modes: - Normal: - Everything uses the computed values from CSS. - MinContent: - Containing blocks act as if they have 0 width. - All line breaking opportunities are taken. - MaxContent: - Containing blocks act as if they have infinite width. - Only forced line breaks are accepted. The above was based on a set of misunderstandings of CSS sizing. A major problem with the above was that *all* containing blocks behaved differently during intrinsic size layout, not just the relevant one. With this patch there are only two layout modes: - Normal: - Everything uses the computed values from CSS. - IntrinsicSizeDetermination: - One or more boxes have size constraints applied. There are two size constraints per layout box, set here: - FormattingState::NodeState::width_constraint - FormattingState::NodeState::height_constraint They are of type SizeConstraint and can be one of None, MinContent, or MaxContent. The default is None. When performing an IntrinsicSizeDetermination layout, we now assign a size constraint to the box we're trying to determine the intrinsic size of, which is then honored by using two new helpers to query the dimensions of containing blocks: - FormattingContext::containing_block_width_for(Box) - FormattingContext::containing_block_height_for(Box) If there's a relevant constraint in effect on the Box, the size of its containing block is adjusted accordingly. This is essentially an implementation of the "available space" constraints from CSS-SIZING-3. I'm sure some things will break from this, and we'll have to deal with that separately. Spec: https://drafts.csswg.org/css-sizing-3/#available
2022-07-09 16:17:47 +03:00
bool should_break(float next_item_width);
LineBox& ensure_last_line_box();
InlineFormattingContext& m_context;
LayoutState& m_layout_state;
LayoutState::UsedValues& m_containing_block_state;
float m_available_width_for_current_line { 0 };
float m_current_y { 0 };
float m_max_height_on_current_line { 0 };
bool m_last_line_needs_update { false };
};
}