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author | Martin Robinson <mrobinson@igalia.com> | 2025-04-19 12:17:03 +0200 |
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committer | GitHub <noreply@github.com> | 2025-04-19 10:17:03 +0000 |
commit | 7787cab521ccc6b4d8533ebe9b45563046e0463d (patch) | |
tree | d1277fa3846f24cc99859310da3d7f099c73bfc5 /components/layout/table/layout.rs | |
parent | 3ab5b8c4472129798b63cfb40b63ae672763b653 (diff) | |
download | servo-7787cab521ccc6b4d8533ebe9b45563046e0463d.tar.gz servo-7787cab521ccc6b4d8533ebe9b45563046e0463d.zip |
layout: Combine `layout_2020` and `layout_thread_2020` into a crate called `layout` (#36613)
Now that legacy layout has been removed, the name `layout_2020` doesn't
make much sense any longer, also it's 2025 now for better or worse. The
split between the "layout thread" and "layout" also doesn't make as much
sense since layout doesn't run on it's own thread. There's a possibility
that it will in the future, but that should be something that the user
of the crate controls rather than layout iself.
This is part of the larger layout interface cleanup and optimization
that
@Looriool and I are doing.
Testing: Covered by existing tests as this is just code movement.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Diffstat (limited to 'components/layout/table/layout.rs')
-rw-r--r-- | components/layout/table/layout.rs | 3063 |
1 files changed, 3063 insertions, 0 deletions
diff --git a/components/layout/table/layout.rs b/components/layout/table/layout.rs new file mode 100644 index 00000000000..57b48ae0bca --- /dev/null +++ b/components/layout/table/layout.rs @@ -0,0 +1,3063 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at https://mozilla.org/MPL/2.0/. */ + +use core::cmp::Ordering; +use std::mem; +use std::ops::Range; + +use app_units::Au; +use atomic_refcell::AtomicRef; +use log::warn; +use rayon::iter::{IndexedParallelIterator, IntoParallelRefIterator, ParallelIterator}; +use servo_arc::Arc; +use style::Zero; +use style::computed_values::border_collapse::T as BorderCollapse; +use style::computed_values::box_sizing::T as BoxSizing; +use style::computed_values::caption_side::T as CaptionSide; +use style::computed_values::empty_cells::T as EmptyCells; +use style::computed_values::position::T as Position; +use style::computed_values::table_layout::T as TableLayoutMode; +use style::computed_values::visibility::T as Visibility; +use style::properties::ComputedValues; +use style::values::computed::{ + BorderStyle, LengthPercentage as ComputedLengthPercentage, Percentage, +}; +use style::values::generics::box_::{GenericVerticalAlign as VerticalAlign, VerticalAlignKeyword}; + +use super::{ + ArcRefCell, CollapsedBorder, CollapsedBorderLine, SpecificTableGridInfo, Table, TableCaption, + TableLayoutStyle, TableSlot, TableSlotCell, TableSlotCoordinates, TableTrack, TableTrackGroup, +}; +use crate::context::LayoutContext; +use crate::formatting_contexts::Baselines; +use crate::fragment_tree::{ + BoxFragment, CollapsedBlockMargins, ExtraBackground, Fragment, FragmentFlags, + PositioningFragment, SpecificLayoutInfo, +}; +use crate::geom::{ + LogicalRect, LogicalSides, LogicalSides1D, LogicalVec2, PhysicalPoint, PhysicalRect, + PhysicalSides, PhysicalVec, Size, SizeConstraint, ToLogical, ToLogicalWithContainingBlock, +}; +use crate::layout_box_base::CacheableLayoutResult; +use crate::positioned::{PositioningContext, PositioningContextLength, relative_adjustement}; +use crate::sizing::{ComputeInlineContentSizes, ContentSizes, InlineContentSizesResult}; +use crate::style_ext::{ + BorderStyleColor, Clamp, ComputedValuesExt, LayoutStyle, PaddingBorderMargin, +}; +use crate::{ + ConstraintSpace, ContainingBlock, ContainingBlockSize, IndefiniteContainingBlock, WritingMode, +}; + +/// A result of a final or speculative layout of a single cell in +/// the table. Note that this is only done for slots that are not +/// covered by spans or empty. +struct CellLayout { + layout: CacheableLayoutResult, + padding: LogicalSides<Au>, + border: LogicalSides<Au>, + positioning_context: PositioningContext, +} + +impl CellLayout { + fn ascent(&self) -> Au { + self.layout + .baselines + .first + .unwrap_or(self.layout.content_block_size) + } + + /// The block size of this laid out cell including its border and padding. + fn outer_block_size(&self) -> Au { + self.layout.content_block_size + self.border.block_sum() + self.padding.block_sum() + } + + /// Whether the cell has no in-flow or out-of-flow contents, other than collapsed whitespace. + /// Note this logic differs from 'empty-cells', which counts abspos contents as empty. + fn is_empty(&self) -> bool { + self.layout.fragments.is_empty() + } + + /// Whether the cell is considered empty for the purpose of the 'empty-cells' property. + fn is_empty_for_empty_cells(&self) -> bool { + self.layout + .fragments + .iter() + .all(|fragment| matches!(fragment, Fragment::AbsoluteOrFixedPositioned(_))) + } +} + +/// Information stored during the layout of rows. +#[derive(Clone, Debug, Default)] +struct RowLayout { + constrained: bool, + has_cell_with_span_greater_than_one: bool, + percent: Percentage, +} + +/// Information stored during the layout of columns. +#[derive(Clone, Debug, Default)] +struct ColumnLayout { + constrained: bool, + has_originating_cells: bool, + content_sizes: ContentSizes, + percentage: Option<Percentage>, +} + +fn max_two_optional_percentages( + a: Option<Percentage>, + b: Option<Percentage>, +) -> Option<Percentage> { + match (a, b) { + (Some(a), Some(b)) => Some(Percentage(a.0.max(b.0))), + _ => a.or(b), + } +} + +impl ColumnLayout { + fn incorporate_cell_measure(&mut self, cell_measure: &CellOrTrackMeasure) { + self.content_sizes.max_assign(cell_measure.content_sizes); + self.percentage = max_two_optional_percentages(self.percentage, cell_measure.percentage); + } +} + +impl CollapsedBorder { + fn new(style_color: BorderStyleColor, width: Au) -> Self { + Self { style_color, width } + } + + fn from_layout_style( + layout_style: &LayoutStyle, + writing_mode: WritingMode, + ) -> LogicalSides<Self> { + let border_style_color = layout_style.style().border_style_color(writing_mode); + let border_width = layout_style.border_width(writing_mode); + LogicalSides { + inline_start: Self::new(border_style_color.inline_start, border_width.inline_start), + inline_end: Self::new(border_style_color.inline_end, border_width.inline_end), + block_start: Self::new(border_style_color.block_start, border_width.block_start), + block_end: Self::new(border_style_color.block_end, border_width.block_end), + } + } + + fn max_assign(&mut self, other: &Self) { + if *self < *other { + *self = other.clone(); + } + } + + fn max_assign_to_slice(&self, slice: &mut [CollapsedBorder]) { + for collapsed_border in slice { + collapsed_border.max_assign(self) + } + } + + fn hide(&mut self) { + self.style_color = BorderStyleColor::hidden(); + self.width = Au::zero(); + } +} + +/// <https://drafts.csswg.org/css-tables/#border-specificity> +/// > Given two borders styles, the border style having the most specificity is the border style which… +/// > 1. … has the value "hidden" as border-style, if only one does +/// > 2. … has the biggest border-width, once converted into css pixels +/// > 3. … has the border-style which comes first in the following list: +/// > double, solid, dashed, dotted, ridge, outset, groove, inset, none +impl PartialOrd for CollapsedBorder { + fn partial_cmp(&self, other: &Self) -> Option<Ordering> { + let is_hidden = |border: &Self| border.style_color.style == BorderStyle::Hidden; + let style_specificity = |border: &Self| match border.style_color.style { + BorderStyle::None => 0, + BorderStyle::Inset => 1, + BorderStyle::Groove => 2, + BorderStyle::Outset => 3, + BorderStyle::Ridge => 4, + BorderStyle::Dotted => 5, + BorderStyle::Dashed => 6, + BorderStyle::Solid => 7, + BorderStyle::Double => 8, + BorderStyle::Hidden => 9, + }; + let candidate = (is_hidden(self).cmp(&is_hidden(other))) + .then_with(|| self.width.cmp(&other.width)) + .then_with(|| style_specificity(self).cmp(&style_specificity(other))); + if !candidate.is_eq() || self.style_color.color == other.style_color.color { + Some(candidate) + } else { + None + } + } +} + +impl Eq for CollapsedBorder {} + +type CollapsedBorders = LogicalVec2<Vec<CollapsedBorderLine>>; + +/// A helper struct that performs the layout of the box tree version +/// of a table into the fragment tree version. This implements +/// <https://drafts.csswg.org/css-tables/#table-layout-algorithm> +pub(crate) struct TableLayout<'a> { + table: &'a Table, + pbm: PaddingBorderMargin, + rows: Vec<RowLayout>, + columns: Vec<ColumnLayout>, + cell_measures: Vec<Vec<LogicalVec2<CellOrTrackMeasure>>>, + /// The calculated width of the table, including space for the grid and also for any + /// captions. + table_width: Au, + /// The table width minus the total horizontal border spacing (if any). This is the + /// width that we will be able to allocate to the columns. + assignable_width: Au, + final_table_height: Au, + distributed_column_widths: Vec<Au>, + row_sizes: Vec<Au>, + /// The accumulated baseline of each row, relative to the top of the row. + row_baselines: Vec<Au>, + cells_laid_out: Vec<Vec<Option<CellLayout>>>, + basis_for_cell_padding_percentage: Au, + /// Information about collapsed borders. + collapsed_borders: Option<CollapsedBorders>, + is_in_fixed_mode: bool, +} + +#[derive(Clone, Debug)] +struct CellOrTrackMeasure { + content_sizes: ContentSizes, + percentage: Option<Percentage>, +} + +impl Zero for CellOrTrackMeasure { + fn zero() -> Self { + Self { + content_sizes: ContentSizes::zero(), + percentage: None, + } + } + + fn is_zero(&self) -> bool { + self.content_sizes.is_zero() && self.percentage.is_none() + } +} + +impl<'a> TableLayout<'a> { + fn new(table: &'a Table) -> TableLayout<'a> { + // The CSSWG resolved that only `inline-size: auto` can prevent fixed table mode. + // <https://github.com/w3c/csswg-drafts/issues/10937#issuecomment-2669150397> + let style = &table.style; + let is_in_fixed_mode = style.get_table().table_layout == TableLayoutMode::Fixed && + !style.box_size(style.writing_mode).inline.is_initial(); + Self { + table, + pbm: PaddingBorderMargin::zero(), + rows: Vec::new(), + columns: Vec::new(), + cell_measures: Vec::new(), + table_width: Au::zero(), + assignable_width: Au::zero(), + final_table_height: Au::zero(), + distributed_column_widths: Vec::new(), + row_sizes: Vec::new(), + row_baselines: Vec::new(), + cells_laid_out: Vec::new(), + basis_for_cell_padding_percentage: Au::zero(), + collapsed_borders: None, + is_in_fixed_mode, + } + } + + /// This is an implementation of *Computing Cell Measures* from + /// <https://drafts.csswg.org/css-tables/#computing-cell-measures>. + pub(crate) fn compute_cell_measures( + &mut self, + layout_context: &LayoutContext, + writing_mode: WritingMode, + ) { + let row_measures = vec![LogicalVec2::zero(); self.table.size.width]; + self.cell_measures = vec![row_measures; self.table.size.height]; + + for row_index in 0..self.table.size.height { + for column_index in 0..self.table.size.width { + let cell = match self.table.slots[row_index][column_index] { + TableSlot::Cell(ref cell) => cell, + _ => continue, + } + .borrow(); + + let layout_style = cell.layout_style(); + let padding = layout_style + .padding(writing_mode) + .percentages_relative_to(Au::zero()); + let border = self + .get_collapsed_border_widths_for_area(LogicalSides { + inline_start: column_index, + inline_end: column_index + cell.colspan, + block_start: row_index, + block_end: row_index + cell.rowspan, + }) + .unwrap_or_else(|| layout_style.border_width(writing_mode)); + + let padding_border_sums = LogicalVec2 { + inline: padding.inline_sum() + border.inline_sum(), + block: padding.block_sum() + border.block_sum(), + }; + + let CellOrColumnOuterSizes { + preferred: preferred_size, + min: min_size, + max: max_size, + percentage: percentage_size, + } = CellOrColumnOuterSizes::new( + &cell.base.style, + writing_mode, + &padding_border_sums, + self.is_in_fixed_mode, + ); + + // <https://drafts.csswg.org/css-tables/#in-fixed-mode> + // > When a table-root is laid out in fixed mode, the content of its table-cells is ignored + // > for the purpose of width computation, the aggregation algorithm for column sizing considers + // > only table-cells belonging to the first row track + let inline_measure = if self.is_in_fixed_mode { + if row_index > 0 { + CellOrTrackMeasure::zero() + } else { + CellOrTrackMeasure { + content_sizes: preferred_size.inline.into(), + percentage: percentage_size.inline, + } + } + } else { + let inline_content_sizes = cell.inline_content_sizes(layout_context) + + padding_border_sums.inline.into(); + assert!( + inline_content_sizes.max_content >= inline_content_sizes.min_content, + "the max-content size should never be smaller than the min-content size" + ); + + // These formulas differ from the spec, but seem to match Gecko and Blink. + let outer_min_content_width = inline_content_sizes + .min_content + .clamp_between_extremums(min_size.inline, max_size.inline); + let outer_max_content_width = if self.columns[column_index].constrained { + inline_content_sizes + .min_content + .max(preferred_size.inline) + .clamp_between_extremums(min_size.inline, max_size.inline) + } else { + inline_content_sizes + .max_content + .max(preferred_size.inline) + .clamp_between_extremums(min_size.inline, max_size.inline) + }; + assert!(outer_min_content_width <= outer_max_content_width); + + CellOrTrackMeasure { + content_sizes: ContentSizes { + min_content: outer_min_content_width, + max_content: outer_max_content_width, + }, + percentage: percentage_size.inline, + } + }; + + // This measure doesn't take into account the `min-content` and `max-content` sizes. + // These sizes are incorporated after the first row layout pass, when the block size + // of the layout is known. + let block_measure = CellOrTrackMeasure { + content_sizes: preferred_size.block.into(), + percentage: percentage_size.block, + }; + + self.cell_measures[row_index][column_index] = LogicalVec2 { + inline: inline_measure, + block: block_measure, + }; + } + } + } + + /// Compute the constrainedness of every column in the table. + /// + /// > A column is constrained if its corresponding table-column-group (if any), its + /// > corresponding table-column (if any), or any of the cells spanning only that + /// > column has a computed width that is not "auto", and is not a percentage. + fn compute_track_constrainedness_and_has_originating_cells( + &mut self, + writing_mode: WritingMode, + ) { + self.rows = vec![RowLayout::default(); self.table.size.height]; + self.columns = vec![ColumnLayout::default(); self.table.size.width]; + + let is_length = |size: &Size<ComputedLengthPercentage>| { + size.to_numeric().is_some_and(|size| !size.has_percentage()) + }; + + for column_index in 0..self.table.size.width { + if let Some(column) = self.table.columns.get(column_index) { + let column = column.borrow(); + if is_length(&column.base.style.box_size(writing_mode).inline) { + self.columns[column_index].constrained = true; + continue; + } + if let Some(column_group_index) = column.group_index { + let column_group = self.table.column_groups[column_group_index].borrow(); + if is_length(&column_group.base.style.box_size(writing_mode).inline) { + self.columns[column_index].constrained = true; + continue; + } + } + } + } + + for row_index in 0..self.table.size.height { + if let Some(row) = self.table.rows.get(row_index) { + let row = row.borrow(); + if is_length(&row.base.style.box_size(writing_mode).block) { + self.rows[row_index].constrained = true; + continue; + } + if let Some(row_group_index) = row.group_index { + let row_group = self.table.row_groups[row_group_index].borrow(); + if is_length(&row_group.base.style.box_size(writing_mode).block) { + self.rows[row_index].constrained = true; + continue; + } + } + } + } + + for column_index in 0..self.table.size.width { + for row_index in 0..self.table.size.height { + let coords = TableSlotCoordinates::new(column_index, row_index); + let cell_constrained = match self.table.resolve_first_cell(coords) { + Some(cell) if cell.colspan == 1 => { + cell.base.style.box_size(writing_mode).map(is_length) + }, + _ => LogicalVec2::default(), + }; + + let rowspan_greater_than_1 = match self.table.slots[row_index][column_index] { + TableSlot::Cell(ref cell) => cell.borrow().rowspan > 1, + _ => false, + }; + + self.rows[row_index].has_cell_with_span_greater_than_one |= rowspan_greater_than_1; + self.rows[row_index].constrained |= cell_constrained.block; + + let has_originating_cell = + matches!(self.table.get_slot(coords), Some(TableSlot::Cell(_))); + self.columns[column_index].has_originating_cells |= has_originating_cell; + self.columns[column_index].constrained |= cell_constrained.inline; + } + } + } + + /// This is an implementation of *Computing Column Measures* from + /// <https://drafts.csswg.org/css-tables/#computing-column-measures>. + fn compute_column_measures(&mut self, writing_mode: WritingMode) { + // Compute the column measures only taking into account cells with colspan == 1. + // This is the base case that will be used to iteratively account for cells with + // larger colspans afterward. + // + // > min-content width of a column based on cells of span up to 1 + // > The largest of: + // > - the width specified for the column: + // > - the outer min-content width of its corresponding table-column, + // > if any (and not auto) + // > - the outer min-content width of its corresponding table-column-group, if any + // > - or 0, if there is none + // > - the outer min-content width of each cell that spans the column whose colSpan + // > is 1 (or just the one in the first row in fixed mode) or 0 if there is none + // > + // > max-content width of a column based on cells of span up to 1 + // > The largest of: + // > - the outer max-content width of its corresponding + // > table-column-group, if any + // > - the outer max-content width of its corresponding table-column, if any + // > - the outer max-content width of each cell that spans the column + // > whose colSpan is 1 (or just the one in the first row if in fixed mode) or 0 + // > if there is no such cell + // > + // > intrinsic percentage width of a column based on cells of span up to 1 + // > The largest of the percentage contributions of each cell that spans the column whose colSpan is + // > 1, of its corresponding table-column (if any), and of its corresponding table-column-group (if + // > any) + // + // TODO: Take into account `table-column` and `table-column-group` lengths. + // TODO: Take into account changes to this computation for fixed table layout. + let mut colspan_cell_constraints = Vec::new(); + for column_index in 0..self.table.size.width { + let column = &mut self.columns[column_index]; + + let column_measure = self.table.get_column_measure_for_column_at_index( + writing_mode, + column_index, + self.is_in_fixed_mode, + ); + column.content_sizes = column_measure.content_sizes; + column.percentage = column_measure.percentage; + + for row_index in 0..self.table.size.height { + let coords = TableSlotCoordinates::new(column_index, row_index); + let cell_measure = &self.cell_measures[row_index][column_index].inline; + + let cell = match self.table.get_slot(coords) { + Some(TableSlot::Cell(cell)) => cell, + _ => continue, + } + .borrow(); + + if cell.colspan != 1 { + colspan_cell_constraints.push(ColspanToDistribute { + starting_column: column_index, + span: cell.colspan, + content_sizes: cell_measure.content_sizes, + percentage: cell_measure.percentage, + }); + continue; + } + + // This takes the max of `min_content`, `max_content`, and + // intrinsic percentage width as described above. + column.incorporate_cell_measure(cell_measure); + } + } + + // Sort the colspanned cell constraints by their span and starting column. + colspan_cell_constraints.sort_by(ColspanToDistribute::comparison_for_sort); + + // Distribute constraints from cells with colspan != 1 to their component columns. + self.distribute_colspanned_cells_to_columns(colspan_cell_constraints); + + // > intrinsic percentage width of a column: + // > the smaller of: + // > * the intrinsic percentage width of the column based on cells of span up to N, + // > where N is the number of columns in the table + // > * 100% minus the sum of the intrinsic percentage width of all prior columns in + // > the table (further left when direction is "ltr" (right for "rtl")) + let mut total_intrinsic_percentage_width = 0.; + for column in self.columns.iter_mut() { + if let Some(ref mut percentage) = column.percentage { + let final_intrinsic_percentage_width = + percentage.0.min(1. - total_intrinsic_percentage_width); + total_intrinsic_percentage_width += final_intrinsic_percentage_width; + *percentage = Percentage(final_intrinsic_percentage_width); + } + } + } + + fn distribute_colspanned_cells_to_columns( + &mut self, + colspan_cell_constraints: Vec<ColspanToDistribute>, + ) { + for colspan_cell_constraints in colspan_cell_constraints { + self.distribute_colspanned_cell_to_columns(colspan_cell_constraints); + } + } + + /// Distribute the inline size from a cell with colspan != 1 to the columns that it spans. + /// This is heavily inspired by the approach that Chromium takes in redistributing colspan + /// cells' inline size to columns (`DistributeColspanCellToColumnsAuto` in + /// `blink/renderer/core/layout/table/table_layout_utils.cc`). + fn distribute_colspanned_cell_to_columns( + &mut self, + colspan_cell_constraints: ColspanToDistribute, + ) { + let border_spacing = self.table.border_spacing().inline; + let column_range = colspan_cell_constraints.range(); + let column_count = column_range.len(); + let total_border_spacing = + border_spacing.scale_by((colspan_cell_constraints.span - 1) as f32); + + let mut percent_columns_count = 0; + let mut columns_percent_sum = 0.; + let mut columns_non_percent_max_inline_size_sum = Au::zero(); + for column in self.columns[column_range.clone()].iter() { + if let Some(percentage) = column.percentage { + percent_columns_count += 1; + columns_percent_sum += percentage.0; + } else { + columns_non_percent_max_inline_size_sum += column.content_sizes.max_content; + } + } + + let colspan_percentage = colspan_cell_constraints.percentage.unwrap_or_default(); + let surplus_percent = colspan_percentage.0 - columns_percent_sum; + if surplus_percent > 0. && column_count > percent_columns_count { + for column in self.columns[column_range.clone()].iter_mut() { + if column.percentage.is_some() { + continue; + } + + let ratio = if columns_non_percent_max_inline_size_sum.is_zero() { + 1. / ((column_count - percent_columns_count) as f32) + } else { + column.content_sizes.max_content.to_f32_px() / + columns_non_percent_max_inline_size_sum.to_f32_px() + }; + column.percentage = Some(Percentage(surplus_percent * ratio)); + } + } + + let colspan_cell_min_size = (colspan_cell_constraints.content_sizes.min_content - + total_border_spacing) + .max(Au::zero()); + let distributed_minimum = Self::distribute_width_to_columns( + colspan_cell_min_size, + &self.columns[column_range.clone()], + ); + { + let column_span = &mut self.columns[colspan_cell_constraints.range()]; + for (column, minimum_size) in column_span.iter_mut().zip(distributed_minimum) { + column.content_sizes.min_content.max_assign(minimum_size); + } + } + + let colspan_cell_max_size = (colspan_cell_constraints.content_sizes.max_content - + total_border_spacing) + .max(Au::zero()); + let distributed_maximum = Self::distribute_width_to_columns( + colspan_cell_max_size, + &self.columns[colspan_cell_constraints.range()], + ); + { + let column_span = &mut self.columns[colspan_cell_constraints.range()]; + for (column, maximum_size) in column_span.iter_mut().zip(distributed_maximum) { + column + .content_sizes + .max_content + .max_assign(maximum_size.max(column.content_sizes.min_content)); + } + } + } + + fn compute_measures(&mut self, layout_context: &LayoutContext, writing_mode: WritingMode) { + self.compute_track_constrainedness_and_has_originating_cells(writing_mode); + self.compute_cell_measures(layout_context, writing_mode); + self.compute_column_measures(writing_mode); + } + + /// Compute the GRIDMIN and GRIDMAX. + fn compute_grid_min_max(&self) -> ContentSizes { + // https://drafts.csswg.org/css-tables/#gridmin: + // > The row/column-grid width minimum (GRIDMIN) width is the sum of the min-content width of + // > all the columns plus cell spacing or borders. + // https://drafts.csswg.org/css-tables/#gridmax: + // > The row/column-grid width maximum (GRIDMAX) width is the sum of the max-content width of + // > all the columns plus cell spacing or borders. + // + // The specification doesn't say what to do with columns with percentages, so we follow the + // approach that LayoutNG takes here. We try to figure out the size contribution + // of the percentage columns, by working backward to find the calculated + // percentage of non-percent columns and using that to calculate the size of the + // percent columns. + let mut largest_percentage_column_max_size = Au::zero(); + let mut percent_sum = 0.; + let mut non_percent_columns_max_sum = Au::zero(); + let mut grid_min_max = ContentSizes::zero(); + for column in self.columns.iter() { + match column.percentage { + Some(percentage) if !percentage.is_zero() => { + largest_percentage_column_max_size.max_assign( + column + .content_sizes + .max_content + .scale_by(1.0 / percentage.0), + ); + percent_sum += percentage.0; + }, + _ => { + non_percent_columns_max_sum += column.content_sizes.max_content; + }, + } + + grid_min_max += column.content_sizes; + } + + grid_min_max + .max_content + .max_assign(largest_percentage_column_max_size); + + // Do not take into account percentage of columns when this table is a descendant + // of a flex, grid, or table container. These modes with percentage columns can + // cause inline width to become infinitely wide. + if !percent_sum.is_zero() && + self.table + .percentage_columns_allowed_for_inline_content_sizes + { + let total_inline_size = + non_percent_columns_max_sum.scale_by(1.0 / (1.0 - percent_sum.min(1.0))); + grid_min_max.max_content.max_assign(total_inline_size); + } + + assert!( + grid_min_max.min_content <= grid_min_max.max_content, + "GRIDMAX should never be smaller than GRIDMIN {:?}", + grid_min_max + ); + + let inline_border_spacing = self.table.total_border_spacing().inline; + grid_min_max.min_content += inline_border_spacing; + grid_min_max.max_content += inline_border_spacing; + grid_min_max + } + + /// Compute CAPMIN: <https://drafts.csswg.org/css-tables/#capmin> + fn compute_caption_minimum_inline_size(&self, layout_context: &LayoutContext) -> Au { + let containing_block = IndefiniteContainingBlock { + size: LogicalVec2::default(), + writing_mode: self.table.style.writing_mode, + }; + self.table + .captions + .iter() + .map(|caption| { + caption + .borrow() + .context + .outer_inline_content_sizes( + layout_context, + &containing_block, + &LogicalVec2::zero(), + false, /* auto_block_size_stretches_to_containing_block */ + ) + .sizes + .min_content + }) + .max() + .unwrap_or_default() + } + + fn compute_table_width(&mut self, containing_block_for_children: &ContainingBlock) { + // This assumes that the parent formatting context computed the correct inline size + // of the table, by enforcing its min-content size as a minimum. + // This should be roughly equivalent to what the spec calls "used width of a table". + // https://drafts.csswg.org/css-tables/#used-width-of-table + self.table_width = containing_block_for_children.size.inline; + + // > The assignable table width is the used width of the table minus the total horizontal + // > border spacing (if any). This is the width that we will be able to allocate to the + // > columns. + self.assignable_width = self.table_width - self.table.total_border_spacing().inline; + + // This is the amount that we will use to resolve percentages in the padding of cells. + // It matches what Gecko and Blink do, though they disagree when there is a big caption. + self.basis_for_cell_padding_percentage = + self.table_width - self.table.border_spacing().inline * 2; + } + + /// Distribute width to columns, performing step 2.4 of table layout from + /// <https://drafts.csswg.org/css-tables/#table-layout-algorithm>. + fn distribute_width_to_columns(target_inline_size: Au, columns: &[ColumnLayout]) -> Vec<Au> { + // No need to do anything if there is no column. + // Note that tables without rows may still have columns. + if columns.is_empty() { + return Vec::new(); + } + + // > First, each column of the table is assigned a sizing type: + // > * percent-column: a column whose any constraint is defined to use a percentage only + // > (with a value different from 0%) + // > * pixel-column: column whose any constraint is defined to use a defined length only + // > (and is not a percent-column) + // > * auto-column: any other column + // > + // > Then, valid sizing methods are to be assigned to the columns by sizing type, yielding + // > the following sizing-guesses: + // > + // > * The min-content sizing-guess is the set of column width assignments where + // > each column is assigned its min-content width. + // > * The min-content-percentage sizing-guess is the set of column width assignments where: + // > * each percent-column is assigned the larger of: + // > * its intrinsic percentage width times the assignable width and + // > * its min-content width. + // > * all other columns are assigned their min-content width. + // > * The min-content-specified sizing-guess is the set of column width assignments where: + // > * each percent-column is assigned the larger of: + // > * its intrinsic percentage width times the assignable width and + // > * its min-content width + // > * any other column that is constrained is assigned its max-content width + // > * all other columns are assigned their min-content width. + // > * The max-content sizing-guess is the set of column width assignments where: + // > * each percent-column is assigned the larger of: + // > * its intrinsic percentage width times the assignable width and + // > * its min-content width + // > * all other columns are assigned their max-content width. + let mut min_content_sizing_guesses = Vec::new(); + let mut min_content_percentage_sizing_guesses = Vec::new(); + let mut min_content_specified_sizing_guesses = Vec::new(); + let mut max_content_sizing_guesses = Vec::new(); + + for column in columns { + let min_content_width = column.content_sizes.min_content; + let max_content_width = column.content_sizes.max_content; + let constrained = column.constrained; + + let ( + min_content_percentage_sizing_guess, + min_content_specified_sizing_guess, + max_content_sizing_guess, + ) = if let Some(percentage) = column.percentage { + let resolved = target_inline_size.scale_by(percentage.0); + let percent_guess = min_content_width.max(resolved); + (percent_guess, percent_guess, percent_guess) + } else if constrained { + (min_content_width, max_content_width, max_content_width) + } else { + (min_content_width, min_content_width, max_content_width) + }; + + min_content_sizing_guesses.push(min_content_width); + min_content_percentage_sizing_guesses.push(min_content_percentage_sizing_guess); + min_content_specified_sizing_guesses.push(min_content_specified_sizing_guess); + max_content_sizing_guesses.push(max_content_sizing_guess); + } + + // > If the assignable table width is less than or equal to the max-content sizing-guess, the + // > used widths of the columns must be the linear combination (with weights adding to 1) of + // > the two consecutive sizing-guesses whose width sums bound the available width. + // + // > Otherwise, the used widths of the columns are the result of starting from the max-content + // > sizing-guess and distributing the excess width to the columns of the table according to + // > the rules for distributing excess width to columns (for used width). + fn sum(guesses: &[Au]) -> Au { + guesses.iter().fold(Au::zero(), |sum, guess| sum + *guess) + } + + let max_content_sizing_sum = sum(&max_content_sizing_guesses); + if target_inline_size >= max_content_sizing_sum { + Self::distribute_extra_width_to_columns( + columns, + &mut max_content_sizing_guesses, + max_content_sizing_sum, + target_inline_size, + ); + return max_content_sizing_guesses; + } + let min_content_specified_sizing_sum = sum(&min_content_specified_sizing_guesses); + if target_inline_size == min_content_specified_sizing_sum { + return min_content_specified_sizing_guesses; + } + let min_content_percentage_sizing_sum = sum(&min_content_percentage_sizing_guesses); + if target_inline_size == min_content_percentage_sizing_sum { + return min_content_percentage_sizing_guesses; + } + let min_content_sizes_sum = sum(&min_content_sizing_guesses); + if target_inline_size <= min_content_sizes_sum { + return min_content_sizing_guesses; + } + + let bounds = |sum_a, sum_b| target_inline_size > sum_a && target_inline_size < sum_b; + + let blend = |a: &[Au], sum_a: Au, b: &[Au], sum_b: Au| { + // First convert the Au units to f32 in order to do floating point division. + let weight_a = (target_inline_size - sum_b).to_f32_px() / (sum_a - sum_b).to_f32_px(); + let weight_b = 1.0 - weight_a; + + let mut remaining_assignable_width = target_inline_size; + let mut widths: Vec<Au> = a + .iter() + .zip(b.iter()) + .map(|(guess_a, guess_b)| { + let column_width = guess_a.scale_by(weight_a) + guess_b.scale_by(weight_b); + // Clamp to avoid exceeding the assignable width. This could otherwise + // happen when dealing with huge values whose sum is clamped to MAX_AU. + let column_width = column_width.min(remaining_assignable_width); + remaining_assignable_width -= column_width; + column_width + }) + .collect(); + + if !remaining_assignable_width.is_zero() { + // The computations above can introduce floating-point imprecisions. + // Since these errors are very small (1Au), it's fine to simply adjust + // the first column such that the total width matches the assignable width + debug_assert!( + remaining_assignable_width >= Au::zero(), + "Sum of columns shouldn't exceed the assignable table width" + ); + debug_assert!( + remaining_assignable_width <= Au::new(widths.len() as i32), + "A deviation of more than one Au per column is unlikely to be caused by float imprecision" + ); + + // We checked if the table had columns at the top of the function, so there + // always is a first column + widths[0] += remaining_assignable_width; + } + + debug_assert!(widths.iter().sum::<Au>() == target_inline_size); + + widths + }; + + if bounds(min_content_sizes_sum, min_content_percentage_sizing_sum) { + return blend( + &min_content_sizing_guesses, + min_content_sizes_sum, + &min_content_percentage_sizing_guesses, + min_content_percentage_sizing_sum, + ); + } + + if bounds( + min_content_percentage_sizing_sum, + min_content_specified_sizing_sum, + ) { + return blend( + &min_content_percentage_sizing_guesses, + min_content_percentage_sizing_sum, + &min_content_specified_sizing_guesses, + min_content_specified_sizing_sum, + ); + } + + assert!(bounds( + min_content_specified_sizing_sum, + max_content_sizing_sum + )); + blend( + &min_content_specified_sizing_guesses, + min_content_specified_sizing_sum, + &max_content_sizing_guesses, + max_content_sizing_sum, + ) + } + + /// This is an implementation of *Distributing excess width to columns* from + /// <https://drafts.csswg.org/css-tables/#distributing-width-to-columns>. + fn distribute_extra_width_to_columns( + columns: &[ColumnLayout], + column_sizes: &mut [Au], + column_sizes_sum: Au, + assignable_width: Au, + ) { + let all_columns = 0..columns.len(); + let extra_inline_size = assignable_width - column_sizes_sum; + + let has_originating_cells = + |column_index: &usize| columns[*column_index].has_originating_cells; + let is_constrained = |column_index: &usize| columns[*column_index].constrained; + let is_unconstrained = |column_index: &usize| !is_constrained(column_index); + let has_percent_greater_than_zero = |column_index: &usize| { + columns[*column_index] + .percentage + .is_some_and(|percentage| percentage.0 > 0.) + }; + let has_percent_zero = |column_index: &usize| !has_percent_greater_than_zero(column_index); + let has_max_content = + |column_index: &usize| !columns[*column_index].content_sizes.max_content.is_zero(); + + let max_content_sum = |column_index: usize| columns[column_index].content_sizes.max_content; + + // > If there are non-constrained columns that have originating cells with intrinsic + // > percentage width of 0% and with nonzero max-content width (aka the columns allowed to + // > grow by this rule), the distributed widths of the columns allowed to grow by this rule + // > are increased in proportion to max-content width so the total increase adds to the + // > excess width. + let unconstrained_max_content_columns = all_columns + .clone() + .filter(is_unconstrained) + .filter(has_originating_cells) + .filter(has_percent_zero) + .filter(has_max_content); + let total_max_content_width = unconstrained_max_content_columns + .clone() + .map(max_content_sum) + .fold(Au::zero(), |a, b| a + b); + if !total_max_content_width.is_zero() { + for column_index in unconstrained_max_content_columns { + column_sizes[column_index] += extra_inline_size.scale_by( + columns[column_index].content_sizes.max_content.to_f32_px() / + total_max_content_width.to_f32_px(), + ); + } + return; + } + + // > Otherwise, if there are non-constrained columns that have originating cells with intrinsic + // > percentage width of 0% (aka the columns allowed to grow by this rule, which thanks to the + // > previous rule must have zero max-content width), the distributed widths of the columns + // > allowed to grow by this rule are increased by equal amounts so the total increase adds to + // > the excess width.V + let unconstrained_no_percent_columns = all_columns + .clone() + .filter(is_unconstrained) + .filter(has_originating_cells) + .filter(has_percent_zero); + let total_unconstrained_no_percent = unconstrained_no_percent_columns.clone().count(); + if total_unconstrained_no_percent > 0 { + let extra_space_per_column = + extra_inline_size.scale_by(1.0 / total_unconstrained_no_percent as f32); + for column_index in unconstrained_no_percent_columns { + column_sizes[column_index] += extra_space_per_column; + } + return; + } + + // > Otherwise, if there are constrained columns with intrinsic percentage width of 0% and + // > with nonzero max-content width (aka the columns allowed to grow by this rule, which, due + // > to other rules, must have originating cells), the distributed widths of the columns + // > allowed to grow by this rule are increased in proportion to max-content width so the + // > total increase adds to the excess width. + let constrained_max_content_columns = all_columns + .clone() + .filter(is_constrained) + .filter(has_originating_cells) + .filter(has_percent_zero) + .filter(has_max_content); + let total_max_content_width = constrained_max_content_columns + .clone() + .map(max_content_sum) + .fold(Au::zero(), |a, b| a + b); + if !total_max_content_width.is_zero() { + for column_index in constrained_max_content_columns { + column_sizes[column_index] += extra_inline_size.scale_by( + columns[column_index].content_sizes.max_content.to_f32_px() / + total_max_content_width.to_f32_px(), + ); + } + return; + } + + // > Otherwise, if there are columns with intrinsic percentage width greater than 0% (aka the + // > columns allowed to grow by this rule, which, due to other rules, must have originating + // > cells), the distributed widths of the columns allowed to grow by this rule are increased + // > in proportion to intrinsic percentage width so the total increase adds to the excess + // > width. + let columns_with_percentage = all_columns.clone().filter(has_percent_greater_than_zero); + let total_percent = columns_with_percentage + .clone() + .map(|column_index| columns[column_index].percentage.unwrap_or_default().0) + .sum::<f32>(); + if total_percent > 0. { + for column_index in columns_with_percentage { + let column_percentage = columns[column_index].percentage.unwrap_or_default(); + column_sizes[column_index] += + extra_inline_size.scale_by(column_percentage.0 / total_percent); + } + return; + } + + // > Otherwise, if there is any such column, the distributed widths of all columns that have + // > originating cells are increased by equal amounts so the total increase adds to the excess + // > width. + let has_originating_cells_columns = all_columns.clone().filter(has_originating_cells); + let total_has_originating_cells = has_originating_cells_columns.clone().count(); + if total_has_originating_cells > 0 { + let extra_space_per_column = + extra_inline_size.scale_by(1.0 / total_has_originating_cells as f32); + for column_index in has_originating_cells_columns { + column_sizes[column_index] += extra_space_per_column; + } + return; + } + + // > Otherwise, the distributed widths of all columns are increased by equal amounts so the + // total increase adds to the excess width. + let extra_space_for_all_columns = extra_inline_size.scale_by(1.0 / columns.len() as f32); + for guess in column_sizes.iter_mut() { + *guess += extra_space_for_all_columns; + } + } + + /// This is an implementation of *Row layout (first pass)* from + /// <https://drafts.csswg.org/css-tables/#row-layout>. + fn layout_cells_in_row( + &mut self, + layout_context: &LayoutContext, + containing_block_for_table: &ContainingBlock, + parent_positioning_context: &mut PositioningContext, + ) { + self.cells_laid_out = self + .table + .slots + .par_iter() + .enumerate() + .map(|(row_index, row_slots)| { + // When building the PositioningContext for this cell, we want it to have the same + // configuration for whatever PositioningContext the contents are ultimately added to. + let collect_for_nearest_positioned_ancestor = parent_positioning_context + .collects_for_nearest_positioned_ancestor() || + self.table.rows.get(row_index).is_some_and(|row| { + let row = row.borrow(); + let row_group_collects_for_nearest_positioned_ancestor = + row.group_index.is_some_and(|group_index| { + self.table.row_groups[group_index] + .borrow() + .base + .style + .establishes_containing_block_for_absolute_descendants( + FragmentFlags::empty(), + ) + }); + row_group_collects_for_nearest_positioned_ancestor || + row.base + .style + .establishes_containing_block_for_absolute_descendants( + FragmentFlags::empty(), + ) + }); + + row_slots + .par_iter() + .enumerate() + .map(|(column_index, slot)| { + let TableSlot::Cell(cell) = slot else { + return None; + }; + + let cell = cell.borrow(); + let area = LogicalSides { + inline_start: column_index, + inline_end: column_index + cell.colspan, + block_start: row_index, + block_end: row_index + cell.rowspan, + }; + let layout_style = cell.layout_style(); + let border = self + .get_collapsed_border_widths_for_area(area) + .unwrap_or_else(|| { + layout_style + .border_width(containing_block_for_table.style.writing_mode) + }); + let padding: LogicalSides<Au> = layout_style + .padding(containing_block_for_table.style.writing_mode) + .percentages_relative_to(self.basis_for_cell_padding_percentage); + let inline_border_padding_sum = border.inline_sum() + padding.inline_sum(); + + let mut total_cell_width: Au = (column_index..column_index + cell.colspan) + .map(|column_index| self.distributed_column_widths[column_index]) + .sum::<Au>() - + inline_border_padding_sum; + total_cell_width = total_cell_width.max(Au::zero()); + + let containing_block_for_children = ContainingBlock { + size: ContainingBlockSize { + inline: total_cell_width, + block: SizeConstraint::default(), + }, + style: &cell.base.style, + }; + + let mut positioning_context = PositioningContext::new_for_subtree( + collect_for_nearest_positioned_ancestor, + ); + + let layout = cell.contents.layout( + layout_context, + &mut positioning_context, + &containing_block_for_children, + false, /* depends_on_block_constraints */ + ); + + Some(CellLayout { + layout, + padding, + border, + positioning_context, + }) + }) + .collect() + }) + .collect(); + + // Now go through all cells laid out and update the cell measure based on the size + // determined during layout. + for row_index in 0..self.table.size.height { + for column_index in 0..self.table.size.width { + let Some(layout) = &self.cells_laid_out[row_index][column_index] else { + continue; + }; + + self.cell_measures[row_index][column_index] + .block + .content_sizes + .max_assign(layout.outer_block_size().into()); + } + } + } + + /// Do the first layout of a table row, after laying out the cells themselves. This is + /// more or less and implementation of <https://drafts.csswg.org/css-tables/#row-layout>. + fn do_first_row_layout(&mut self, writing_mode: WritingMode) -> Vec<Au> { + let mut row_sizes = (0..self.table.size.height) + .map(|row_index| { + let (mut max_ascent, mut max_descent, mut max_row_height) = + (Au::zero(), Au::zero(), Au::zero()); + + for column_index in 0..self.table.size.width { + let cell = match self.table.slots[row_index][column_index] { + TableSlot::Cell(ref cell) => cell, + _ => continue, + }; + + let layout = match self.cells_laid_out[row_index][column_index] { + Some(ref layout) => layout, + None => { + warn!( + "Did not find a layout at a slot index with an originating cell." + ); + continue; + }, + }; + + let cell = cell.borrow(); + let outer_block_size = layout.outer_block_size(); + if cell.rowspan == 1 { + max_row_height.max_assign(outer_block_size); + } + + if cell.effective_vertical_align() == VerticalAlignKeyword::Baseline { + let ascent = layout.ascent(); + let border_padding_start = + layout.border.block_start + layout.padding.block_start; + let border_padding_end = layout.border.block_end + layout.padding.block_end; + max_ascent.max_assign(ascent + border_padding_start); + + // Only take into account the descent of this cell if doesn't span + // rows. The descent portion of the cell in cells that do span rows + // may extend into other rows. + if cell.rowspan == 1 { + max_descent.max_assign( + layout.layout.content_block_size - ascent + border_padding_end, + ); + } + } + } + self.row_baselines.push(max_ascent); + max_row_height.max(max_ascent + max_descent) + }) + .collect(); + self.calculate_row_sizes_after_first_layout(&mut row_sizes, writing_mode); + row_sizes + } + + #[allow(clippy::ptr_arg)] // Needs to be a vec because of the function above + /// After doing layout of table rows, calculate final row size and distribute space across + /// rowspanned cells. This follows the implementation of LayoutNG and the priority + /// agorithm described at <https://github.com/w3c/csswg-drafts/issues/4418>. + fn calculate_row_sizes_after_first_layout( + &mut self, + row_sizes: &mut Vec<Au>, + writing_mode: WritingMode, + ) { + let mut cells_to_distribute = Vec::new(); + let mut total_percentage = 0.; + #[allow(clippy::needless_range_loop)] // It makes sense to use it here + for row_index in 0..self.table.size.height { + let row_measure = self + .table + .get_row_measure_for_row_at_index(writing_mode, row_index); + row_sizes[row_index].max_assign(row_measure.content_sizes.min_content); + + let mut percentage = row_measure.percentage.unwrap_or_default().0; + for column_index in 0..self.table.size.width { + let cell_percentage = self.cell_measures[row_index][column_index] + .block + .percentage + .unwrap_or_default() + .0; + percentage = percentage.max(cell_percentage); + + let cell_measure = &self.cell_measures[row_index][column_index].block; + let cell = match self.table.slots[row_index][column_index] { + TableSlot::Cell(ref cell) if cell.borrow().rowspan > 1 => cell, + TableSlot::Cell(_) => { + // If this is an originating cell, that isn't spanning, then we make sure the row is + // at least big enough to hold the cell. + row_sizes[row_index].max_assign(cell_measure.content_sizes.max_content); + continue; + }, + _ => continue, + }; + + cells_to_distribute.push(RowspanToDistribute { + coordinates: TableSlotCoordinates::new(column_index, row_index), + cell: cell.borrow(), + measure: cell_measure, + }); + } + + self.rows[row_index].percent = Percentage(percentage.min(1. - total_percentage)); + total_percentage += self.rows[row_index].percent.0; + } + + cells_to_distribute.sort_by(|a, b| { + if a.range() == b.range() { + return a + .measure + .content_sizes + .min_content + .cmp(&b.measure.content_sizes.min_content); + } + if a.fully_encloses(b) { + return std::cmp::Ordering::Greater; + } + if b.fully_encloses(a) { + return std::cmp::Ordering::Less; + } + a.coordinates.y.cmp(&b.coordinates.y) + }); + + for rowspan_to_distribute in cells_to_distribute { + let rows_spanned = rowspan_to_distribute.range(); + let current_rows_size: Au = rows_spanned.clone().map(|index| row_sizes[index]).sum(); + let border_spacing_spanned = + self.table.border_spacing().block * (rows_spanned.len() - 1) as i32; + let excess_size = (rowspan_to_distribute.measure.content_sizes.min_content - + current_rows_size - + border_spacing_spanned) + .max(Au::zero()); + + self.distribute_extra_size_to_rows( + excess_size, + rows_spanned, + row_sizes, + None, + true, /* rowspan_distribution */ + ); + } + } + + /// An implementation of the same extra block size distribution algorithm used in + /// LayoutNG and described at <https://github.com/w3c/csswg-drafts/issues/4418>. + fn distribute_extra_size_to_rows( + &self, + mut excess_size: Au, + track_range: Range<usize>, + track_sizes: &mut [Au], + percentage_resolution_size: Option<Au>, + rowspan_distribution: bool, + ) { + if excess_size.is_zero() { + return; + } + + let is_constrained = |track_index: &usize| self.rows[*track_index].constrained; + let is_unconstrained = |track_index: &usize| !is_constrained(track_index); + let is_empty: Vec<bool> = track_sizes.iter().map(|size| size.is_zero()).collect(); + let is_not_empty = |track_index: &usize| !is_empty[*track_index]; + let other_row_that_starts_a_rowspan = |track_index: &usize| { + *track_index != track_range.start && + self.rows[*track_index].has_cell_with_span_greater_than_one + }; + + // If we have a table height (not during rowspan distribution), first distribute to rows + // that have percentage sizes proportionally to the size missing to reach the percentage + // of table height required. + if let Some(percentage_resolution_size) = percentage_resolution_size { + let get_percent_block_size_deficit = |row_index: usize, track_size: Au| { + let size_needed_for_percent = + percentage_resolution_size.scale_by(self.rows[row_index].percent.0); + (size_needed_for_percent - track_size).max(Au::zero()) + }; + let percent_block_size_deficit: Au = track_range + .clone() + .map(|index| get_percent_block_size_deficit(index, track_sizes[index])) + .sum(); + let percent_distributable_block_size = percent_block_size_deficit.min(excess_size); + if percent_distributable_block_size > Au::zero() { + for track_index in track_range.clone() { + let row_deficit = + get_percent_block_size_deficit(track_index, track_sizes[track_index]); + if row_deficit > Au::zero() { + let ratio = + row_deficit.to_f32_px() / percent_block_size_deficit.to_f32_px(); + let size = percent_distributable_block_size.scale_by(ratio); + track_sizes[track_index] += size; + excess_size -= size; + } + } + } + } + + // If this is rowspan distribution and there are rows other than the first row that have a + // cell with rowspan > 1, distribute the extra space equally to those rows. + if rowspan_distribution { + let rows_that_start_rowspan: Vec<usize> = track_range + .clone() + .filter(other_row_that_starts_a_rowspan) + .collect(); + if !rows_that_start_rowspan.is_empty() { + let scale = 1.0 / rows_that_start_rowspan.len() as f32; + for track_index in rows_that_start_rowspan.iter() { + track_sizes[*track_index] += excess_size.scale_by(scale); + } + return; + } + } + + // If there are unconstrained non-empty rows, grow them all proportionally to their current size. + let unconstrained_non_empty_rows: Vec<usize> = track_range + .clone() + .filter(is_unconstrained) + .filter(is_not_empty) + .collect(); + if !unconstrained_non_empty_rows.is_empty() { + let total_size: Au = unconstrained_non_empty_rows + .iter() + .map(|index| track_sizes[*index]) + .sum(); + for track_index in unconstrained_non_empty_rows.iter() { + let scale = track_sizes[*track_index].to_f32_px() / total_size.to_f32_px(); + track_sizes[*track_index] += excess_size.scale_by(scale); + } + return; + } + + let (non_empty_rows, empty_rows): (Vec<usize>, Vec<usize>) = + track_range.clone().partition(is_not_empty); + let only_have_empty_rows = empty_rows.len() == track_range.len(); + if !empty_rows.is_empty() { + // If this is rowspan distribution and there are only empty rows, just grow the + // last one. + if rowspan_distribution && only_have_empty_rows { + track_sizes[*empty_rows.last().unwrap()] += excess_size; + return; + } + + // Otherwise, if we only have empty rows or if all the non-empty rows are constrained, + // then grow the empty rows. + let non_empty_rows_all_constrained = !non_empty_rows.iter().any(is_unconstrained); + if only_have_empty_rows || non_empty_rows_all_constrained { + // If there are both unconstrained and constrained empty rows, only increase the + // size of the unconstrained ones, otherwise increase the size of all empty rows. + let mut rows_to_grow = &empty_rows; + let unconstrained_empty_rows: Vec<usize> = rows_to_grow + .iter() + .copied() + .filter(is_unconstrained) + .collect(); + if !unconstrained_empty_rows.is_empty() { + rows_to_grow = &unconstrained_empty_rows; + } + + // All empty rows that will grow equally. + let scale = 1.0 / rows_to_grow.len() as f32; + for track_index in rows_to_grow.iter() { + track_sizes[*track_index] += excess_size.scale_by(scale); + } + return; + } + } + + // If there are non-empty rows, they all grow in proportion to their current size, + // whether or not they are constrained. + if !non_empty_rows.is_empty() { + let total_size: Au = non_empty_rows.iter().map(|index| track_sizes[*index]).sum(); + for track_index in non_empty_rows.iter() { + let scale = track_sizes[*track_index].to_f32_px() / total_size.to_f32_px(); + track_sizes[*track_index] += excess_size.scale_by(scale); + } + } + } + + /// Given computed row sizes, compute the final block size of the table and distribute extra + /// block size to table rows. + fn compute_table_height_and_final_row_heights( + &mut self, + mut row_sizes: Vec<Au>, + containing_block_for_children: &ContainingBlock, + ) { + // The table content height is the maximum of the computed table height from style and the + // sum of computed row heights from row layout plus size from borders and spacing. + // TODO: for `height: stretch`, the block size of the containing block is the available + // space for the entire table wrapper, but here we are using that amount for the table grid. + // Therefore, if there is a caption, this will cause overflow. Gecko and WebKit have the + // same problem, but not Blink. + let table_height_from_style = match containing_block_for_children.size.block { + SizeConstraint::Definite(size) => size, + SizeConstraint::MinMax(min, _) => min, + }; + + let block_border_spacing = self.table.total_border_spacing().block; + let table_height_from_rows = row_sizes.iter().sum::<Au>() + block_border_spacing; + self.final_table_height = table_height_from_rows.max(table_height_from_style); + + // If the table height is defined by the rows sizes, there is no extra space to distribute + // to rows. + if self.final_table_height == table_height_from_rows { + self.row_sizes = row_sizes; + return; + } + + // There was extra block size added to the table from the table style, so distribute this + // extra space to rows using the same distribution algorithm used for distributing rowspan + // space. + // TODO: This should first distribute space to row groups and then to rows. + self.distribute_extra_size_to_rows( + self.final_table_height - table_height_from_rows, + 0..self.table.size.height, + &mut row_sizes, + Some(self.final_table_height), + false, /* rowspan_distribution */ + ); + self.row_sizes = row_sizes; + } + + fn layout_caption( + &self, + caption: &TableCaption, + layout_context: &LayoutContext, + parent_positioning_context: &mut PositioningContext, + ) -> BoxFragment { + let mut positioning_context = PositioningContext::new_for_style(caption.context.style()); + let containing_block = &ContainingBlock { + size: ContainingBlockSize { + inline: self.table_width + self.pbm.padding_border_sums.inline, + block: SizeConstraint::default(), + }, + style: &self.table.style, + }; + + // The parent of a caption is the table wrapper, which establishes an independent + // formatting context. Therefore, we don't ignore block margins when resolving a + // stretch block size. https://drafts.csswg.org/css-sizing-4/#stretch-fit-sizing + let ignore_block_margins_for_stretch = LogicalSides1D::new(false, false); + + let mut box_fragment = caption.context.layout_in_flow_block_level( + layout_context, + positioning_context + .as_mut() + .unwrap_or(parent_positioning_context), + containing_block, + None, /* sequential_layout_state */ + ignore_block_margins_for_stretch, + ); + + if let Some(mut positioning_context) = positioning_context.take() { + positioning_context.layout_collected_children(layout_context, &mut box_fragment); + parent_positioning_context.append(positioning_context); + } + + box_fragment + } + + /// Lay out the table (grid and captions) of this [`TableLayout`] into fragments. This should + /// only be be called after calling [`TableLayout.compute_measures`]. + #[cfg_attr( + feature = "tracing", + tracing::instrument( + name = "Table::layout", + skip_all, + fields(servo_profiling = true), + level = "trace", + ) + )] + fn layout( + mut self, + layout_context: &LayoutContext, + positioning_context: &mut PositioningContext, + containing_block_for_children: &ContainingBlock, + containing_block_for_table: &ContainingBlock, + depends_on_block_constraints: bool, + ) -> CacheableLayoutResult { + let table_writing_mode = containing_block_for_children.style.writing_mode; + self.compute_border_collapse(table_writing_mode); + let layout_style = self.table.layout_style(Some(&self)); + let depends_on_block_constraints = depends_on_block_constraints || + layout_style + .content_box_sizes_and_padding_border_margin(&containing_block_for_table.into()) + .depends_on_block_constraints; + + self.pbm = layout_style + .padding_border_margin_with_writing_mode_and_containing_block_inline_size( + table_writing_mode, + containing_block_for_table.size.inline, + ); + self.compute_measures(layout_context, table_writing_mode); + self.compute_table_width(containing_block_for_children); + + // The table wrapper is the one that has the CSS properties for the grid's border and padding. This + // weirdness is difficult to express in Servo's layout system. We have the wrapper size itself as if + // those properties applied to it and then just account for the discrepency in sizing here. In reality, + // the wrapper does not draw borders / backgrounds and all of its content (grid and captions) are + // placed with a negative offset in the table wrapper's content box so that they overlap the undrawn + // border / padding area. + // + // TODO: This is a pretty large hack. It would be nicer to actually have the grid sized properly, + // but it works for now. + // + // Get the padding, border, and margin of the table using the inline size of the table's containing + // block but in the writing of the table itself. + // TODO: This is broken for orthoganol flows, because the inline size of the parent isn't necessarily + // the inline size of the table. + let containing_block_for_logical_conversion = ContainingBlock { + size: ContainingBlockSize { + inline: self.table_width, + block: containing_block_for_table.size.block, + }, + style: containing_block_for_children.style, + }; + let offset_from_wrapper = -self.pbm.padding - self.pbm.border; + let mut current_block_offset = offset_from_wrapper.block_start; + + let mut table_layout = CacheableLayoutResult { + fragments: Vec::new(), + content_block_size: Zero::zero(), + content_inline_size_for_table: None, + baselines: Baselines::default(), + depends_on_block_constraints, + specific_layout_info: Some(SpecificLayoutInfo::TableWrapper), + collapsible_margins_in_children: CollapsedBlockMargins::zero(), + }; + + table_layout + .fragments + .extend(self.table.captions.iter().filter_map(|caption| { + let caption = caption.borrow(); + if caption.context.style().clone_caption_side() != CaptionSide::Top { + return None; + } + + let original_positioning_context_length = positioning_context.len(); + let mut caption_fragment = + self.layout_caption(&caption, layout_context, positioning_context); + + // The caption is not placed yet. Construct a rectangle for it in the adjusted containing block + // for the table children and only then convert the result to physical geometry. + let caption_pbm = caption_fragment + .padding_border_margin() + .to_logical(table_writing_mode); + + let caption_relative_offset = match caption_fragment.style.clone_position() { + Position::Relative => { + relative_adjustement(&caption_fragment.style, containing_block_for_children) + }, + _ => LogicalVec2::zero(), + }; + + caption_fragment.content_rect = LogicalRect { + start_corner: LogicalVec2 { + inline: offset_from_wrapper.inline_start + caption_pbm.inline_start, + block: current_block_offset + caption_pbm.block_start, + } + caption_relative_offset, + size: caption_fragment + .content_rect + .size + .to_logical(table_writing_mode), + } + .as_physical(Some(&containing_block_for_logical_conversion)); + + current_block_offset += caption_fragment + .margin_rect() + .size + .to_logical(table_writing_mode) + .block; + + let caption_fragment = Fragment::Box(ArcRefCell::new(caption_fragment)); + positioning_context.adjust_static_position_of_hoisted_fragments( + &caption_fragment, + original_positioning_context_length, + ); + + caption.context.base.set_fragment(caption_fragment.clone()); + Some(caption_fragment) + })); + + let original_positioning_context_length = positioning_context.len(); + let mut grid_fragment = self.layout_grid( + layout_context, + positioning_context, + &containing_block_for_logical_conversion, + containing_block_for_children, + ); + + // Take the baseline of the grid fragment, after adjusting it to be in the coordinate system + // of the table wrapper. + let logical_grid_content_rect = grid_fragment + .content_rect + .to_logical(&containing_block_for_logical_conversion); + let grid_pbm = grid_fragment + .padding_border_margin() + .to_logical(table_writing_mode); + table_layout.baselines = grid_fragment.baselines(table_writing_mode).offset( + current_block_offset + + logical_grid_content_rect.start_corner.block + + grid_pbm.block_start, + ); + + grid_fragment.content_rect = LogicalRect { + start_corner: LogicalVec2 { + inline: offset_from_wrapper.inline_start + grid_pbm.inline_start, + block: current_block_offset + grid_pbm.block_start, + }, + size: grid_fragment + .content_rect + .size + .to_logical(table_writing_mode), + } + .as_physical(Some(&containing_block_for_logical_conversion)); + + current_block_offset += grid_fragment + .border_rect() + .size + .to_logical(table_writing_mode) + .block; + if logical_grid_content_rect.size.inline < self.table_width { + // This can happen when collapsing columns + table_layout.content_inline_size_for_table = + Some(logical_grid_content_rect.size.inline); + } + + let grid_fragment = Fragment::Box(ArcRefCell::new(grid_fragment)); + positioning_context.adjust_static_position_of_hoisted_fragments( + &grid_fragment, + original_positioning_context_length, + ); + table_layout.fragments.push(grid_fragment); + + table_layout + .fragments + .extend(self.table.captions.iter().filter_map(|caption| { + let caption = caption.borrow(); + if caption.context.style().clone_caption_side() != CaptionSide::Bottom { + return None; + } + + let original_positioning_context_length = positioning_context.len(); + let mut caption_fragment = + self.layout_caption(&caption, layout_context, positioning_context); + + // The caption is not placed yet. Construct a rectangle for it in the adjusted containing block + // for the table children and only then convert the result to physical geometry. + let caption_pbm = caption_fragment + .padding_border_margin() + .to_logical(table_writing_mode); + caption_fragment.content_rect = LogicalRect { + start_corner: LogicalVec2 { + inline: offset_from_wrapper.inline_start + caption_pbm.inline_start, + block: current_block_offset + caption_pbm.block_start, + }, + size: caption_fragment + .content_rect + .size + .to_logical(table_writing_mode), + } + .as_physical(Some(&containing_block_for_logical_conversion)); + + current_block_offset += caption_fragment + .margin_rect() + .size + .to_logical(table_writing_mode) + .block; + + let caption_fragment = Fragment::Box(ArcRefCell::new(caption_fragment)); + positioning_context.adjust_static_position_of_hoisted_fragments( + &caption_fragment, + original_positioning_context_length, + ); + + caption.context.base.set_fragment(caption_fragment.clone()); + Some(caption_fragment) + })); + + table_layout.content_block_size = current_block_offset + offset_from_wrapper.block_end; + table_layout + } + + /// Lay out the grid portion of this [`TableLayout`] into fragments. This should only be be + /// called after calling [`TableLayout.compute_measures`]. + fn layout_grid( + &mut self, + layout_context: &LayoutContext, + positioning_context: &mut PositioningContext, + containing_block_for_logical_conversion: &ContainingBlock, + containing_block_for_children: &ContainingBlock, + ) -> BoxFragment { + self.distributed_column_widths = + Self::distribute_width_to_columns(self.assignable_width, &self.columns); + self.layout_cells_in_row( + layout_context, + containing_block_for_children, + positioning_context, + ); + let table_writing_mode = containing_block_for_children.style.writing_mode; + let first_layout_row_heights = self.do_first_row_layout(table_writing_mode); + self.compute_table_height_and_final_row_heights( + first_layout_row_heights, + containing_block_for_children, + ); + + assert_eq!(self.table.size.height, self.row_sizes.len()); + assert_eq!(self.table.size.width, self.distributed_column_widths.len()); + + if self.table.size.width == 0 && self.table.size.height == 0 { + let content_rect = LogicalRect { + start_corner: LogicalVec2::zero(), + size: LogicalVec2 { + inline: self.table_width, + block: self.final_table_height, + }, + } + .as_physical(Some(containing_block_for_logical_conversion)); + return BoxFragment::new( + self.table.grid_base_fragment_info, + self.table.grid_style.clone(), + Vec::new(), + content_rect, + self.pbm.padding.to_physical(table_writing_mode), + self.pbm.border.to_physical(table_writing_mode), + PhysicalSides::zero(), + None, /* clearance */ + ) + .with_specific_layout_info(self.specific_layout_info_for_grid()); + } + + let mut table_fragments = Vec::new(); + let table_and_track_dimensions = TableAndTrackDimensions::new(self); + self.make_fragments_for_columns_and_column_groups( + &table_and_track_dimensions, + &mut table_fragments, + ); + + let mut baselines = Baselines::default(); + let mut row_group_fragment_layout = None; + for row_index in 0..self.table.size.height { + // From <https://drafts.csswg.org/css-align-3/#baseline-export> + // > If any cells in the row participate in first baseline/last baseline alignment along + // > the inline axis, the first/last baseline set of the row is generated from their + // > shared alignment baseline and the row’s first available font, after alignment has + // > been performed. Otherwise, the first/last baseline set of the row is synthesized from + // > the lowest and highest content edges of the cells in the row. [CSS2] + // + // If any cell below has baseline alignment, these values will be overwritten, + // but they are initialized to the content edge of the first row. + if row_index == 0 { + let row_end = table_and_track_dimensions + .get_row_rect(0) + .max_block_position(); + baselines.first = Some(row_end); + baselines.last = Some(row_end); + } + + if self.is_row_collapsed(row_index) { + continue; + } + + let table_row = self.table.rows[row_index].borrow(); + let mut row_fragment_layout = RowFragmentLayout::new( + &table_row, + row_index, + &table_and_track_dimensions, + &self.table.style, + ); + + let old_row_group_index = row_group_fragment_layout + .as_ref() + .map(|layout: &RowGroupFragmentLayout| layout.index); + if table_row.group_index != old_row_group_index { + // First create the Fragment for any existing RowGroupFragmentLayout. + if let Some(old_row_group_layout) = row_group_fragment_layout.take() { + table_fragments.push(old_row_group_layout.finish( + layout_context, + positioning_context, + containing_block_for_logical_conversion, + containing_block_for_children, + )); + } + + // Then, create a new RowGroupFragmentLayout for the current and potentially subsequent rows. + if let Some(new_group_index) = table_row.group_index { + row_group_fragment_layout = Some(RowGroupFragmentLayout::new( + self.table.row_groups[new_group_index].clone(), + new_group_index, + &table_and_track_dimensions, + )); + } + } + + let column_indices = 0..self.table.size.width; + row_fragment_layout.fragments.reserve(self.table.size.width); + for column_index in column_indices { + if self.is_column_collapsed(column_index) { + continue; + } + + self.do_final_cell_layout( + row_index, + column_index, + &table_and_track_dimensions, + &mut baselines, + &mut row_fragment_layout, + row_group_fragment_layout.as_mut(), + positioning_context, + ); + } + + let row_fragment = row_fragment_layout.finish( + layout_context, + positioning_context, + containing_block_for_logical_conversion, + containing_block_for_children, + &mut row_group_fragment_layout, + ); + + match row_group_fragment_layout.as_mut() { + Some(layout) => layout.fragments.push(row_fragment), + None => table_fragments.push(row_fragment), + } + } + + if let Some(row_group_layout) = row_group_fragment_layout.take() { + table_fragments.push(row_group_layout.finish( + layout_context, + positioning_context, + containing_block_for_logical_conversion, + containing_block_for_children, + )); + } + + let content_rect = LogicalRect { + start_corner: LogicalVec2::zero(), + size: LogicalVec2 { + inline: table_and_track_dimensions.table_rect.max_inline_position(), + block: table_and_track_dimensions.table_rect.max_block_position(), + }, + } + .as_physical(Some(containing_block_for_logical_conversion)); + BoxFragment::new( + self.table.grid_base_fragment_info, + self.table.grid_style.clone(), + table_fragments, + content_rect, + self.pbm.padding.to_physical(table_writing_mode), + self.pbm.border.to_physical(table_writing_mode), + PhysicalSides::zero(), + None, /* clearance */ + ) + .with_baselines(baselines) + .with_specific_layout_info(self.specific_layout_info_for_grid()) + } + + fn specific_layout_info_for_grid(&mut self) -> Option<SpecificLayoutInfo> { + mem::take(&mut self.collapsed_borders).map(|mut collapsed_borders| { + // TODO: It would probably be better to use `TableAndTrackDimensions`, since that + // has already taken care of collapsed tracks and knows the final track positions. + let mut track_sizes = LogicalVec2 { + inline: mem::take(&mut self.distributed_column_widths), + block: mem::take(&mut self.row_sizes), + }; + for (column_index, column_size) in track_sizes.inline.iter_mut().enumerate() { + if self.is_column_collapsed(column_index) { + mem::take(column_size); + } + } + for (row_index, row_size) in track_sizes.block.iter_mut().enumerate() { + if self.is_row_collapsed(row_index) { + mem::take(row_size); + } + } + let writing_mode = self.table.style.writing_mode; + if !writing_mode.is_bidi_ltr() { + track_sizes.inline.reverse(); + collapsed_borders.inline.reverse(); + for border_line in &mut collapsed_borders.block { + border_line.reverse(); + } + } + SpecificLayoutInfo::TableGridWithCollapsedBorders(Box::new(SpecificTableGridInfo { + collapsed_borders: if writing_mode.is_horizontal() { + PhysicalVec::new(collapsed_borders.inline, collapsed_borders.block) + } else { + PhysicalVec::new(collapsed_borders.block, collapsed_borders.inline) + }, + track_sizes: if writing_mode.is_horizontal() { + PhysicalVec::new(track_sizes.inline, track_sizes.block) + } else { + PhysicalVec::new(track_sizes.block, track_sizes.inline) + }, + })) + }) + } + + fn is_row_collapsed(&self, row_index: usize) -> bool { + let Some(row) = &self.table.rows.get(row_index) else { + return false; + }; + + let row = row.borrow(); + if row.base.style.get_inherited_box().visibility == Visibility::Collapse { + return true; + } + let row_group = match row.group_index { + Some(group_index) => self.table.row_groups[group_index].borrow(), + None => return false, + }; + row_group.base.style.get_inherited_box().visibility == Visibility::Collapse + } + + fn is_column_collapsed(&self, column_index: usize) -> bool { + let Some(column) = &self.table.columns.get(column_index) else { + return false; + }; + let column = column.borrow(); + if column.base.style.get_inherited_box().visibility == Visibility::Collapse { + return true; + } + let col_group = match column.group_index { + Some(group_index) => self.table.column_groups[group_index].borrow(), + None => return false, + }; + col_group.base.style.get_inherited_box().visibility == Visibility::Collapse + } + + #[allow(clippy::too_many_arguments)] + fn do_final_cell_layout( + &mut self, + row_index: usize, + column_index: usize, + dimensions: &TableAndTrackDimensions, + baselines: &mut Baselines, + row_fragment_layout: &mut RowFragmentLayout, + row_group_fragment_layout: Option<&mut RowGroupFragmentLayout>, + positioning_context_for_table: &mut PositioningContext, + ) { + // The PositioningContext for cells is, in order or preference, the PositioningContext of the row, + // the PositioningContext of the row group, or the PositioningContext of the table. + let row_group_positioning_context = + row_group_fragment_layout.and_then(|layout| layout.positioning_context.as_mut()); + let positioning_context = row_fragment_layout + .positioning_context + .as_mut() + .or(row_group_positioning_context) + .unwrap_or(positioning_context_for_table); + + let layout = match self.cells_laid_out[row_index][column_index].take() { + Some(layout) => layout, + None => { + return; + }, + }; + let cell = match self.table.slots[row_index][column_index] { + TableSlot::Cell(ref cell) => cell, + _ => { + warn!("Did not find a non-spanned cell at index with layout."); + return; + }, + } + .borrow(); + + // If this cell has baseline alignment, it can adjust the table's overall baseline. + let row_block_offset = row_fragment_layout.rect.start_corner.block; + let row_baseline = self.row_baselines[row_index]; + if cell.effective_vertical_align() == VerticalAlignKeyword::Baseline && !layout.is_empty() { + let baseline = row_block_offset + row_baseline; + if row_index == 0 { + baselines.first = Some(baseline); + } + baselines.last = Some(baseline); + } + let mut row_relative_cell_rect = dimensions.get_cell_rect( + TableSlotCoordinates::new(column_index, row_index), + cell.rowspan, + cell.colspan, + ); + row_relative_cell_rect.start_corner -= row_fragment_layout.rect.start_corner; + let mut fragment = cell.create_fragment( + layout, + row_relative_cell_rect, + row_baseline, + positioning_context, + &self.table.style, + &row_fragment_layout.containing_block, + ); + + // Make a table part rectangle relative to the row fragment for the purposes of + // drawing extra backgrounds. + // + // This rectangle is an offset between the row fragment and the other table + // part rectangle (row group, column, column group). Everything between them + // is laid out in a left-to-right fashion, but respecting the verticality of + // the writing mode. This is why below, only the axes are flipped, but the + // rectangle is not flipped for RTL. + let make_relative_to_row_start = |mut rect: LogicalRect<Au>| { + rect.start_corner -= row_fragment_layout.rect.start_corner; + let writing_mode = self.table.style.writing_mode; + PhysicalRect::new( + if writing_mode.is_horizontal() { + PhysicalPoint::new(rect.start_corner.inline, rect.start_corner.block) + } else { + PhysicalPoint::new(rect.start_corner.block, rect.start_corner.inline) + }, + rect.size.to_physical_size(writing_mode), + ) + }; + + let column = self.table.columns.get(column_index); + let column_group = column + .and_then(|column| column.borrow().group_index) + .and_then(|index| self.table.column_groups.get(index)); + if let Some(column_group) = column_group { + let column_group = column_group.borrow(); + let rect = make_relative_to_row_start(dimensions.get_column_group_rect(&column_group)); + fragment.add_extra_background(ExtraBackground { + style: column_group.base.style.clone(), + rect, + }) + } + if let Some(column) = column { + let column = column.borrow(); + if !column.is_anonymous { + let rect = make_relative_to_row_start(dimensions.get_column_rect(column_index)); + fragment.add_extra_background(ExtraBackground { + style: column.base.style.clone(), + rect, + }) + } + } + let row = self.table.rows.get(row_index); + let row_group = row + .and_then(|row| row.borrow().group_index) + .and_then(|index| self.table.row_groups.get(index)); + if let Some(row_group) = row_group { + let rect = + make_relative_to_row_start(dimensions.get_row_group_rect(&row_group.borrow())); + fragment.add_extra_background(ExtraBackground { + style: row_group.borrow().base.style.clone(), + rect, + }) + } + if let Some(row) = row { + let row = row.borrow(); + let rect = make_relative_to_row_start(row_fragment_layout.rect); + fragment.add_extra_background(ExtraBackground { + style: row.base.style.clone(), + rect, + }) + } + + let fragment = Fragment::Box(ArcRefCell::new(fragment)); + cell.base.set_fragment(fragment.clone()); + row_fragment_layout.fragments.push(fragment); + } + + fn make_fragments_for_columns_and_column_groups( + &self, + dimensions: &TableAndTrackDimensions, + fragments: &mut Vec<Fragment>, + ) { + for column_group in self.table.column_groups.iter() { + let column_group = column_group.borrow(); + if !column_group.is_empty() { + fragments.push(Fragment::Positioning(PositioningFragment::new_empty( + column_group.base.base_fragment_info, + dimensions + .get_column_group_rect(&column_group) + .as_physical(None), + column_group.base.style.clone(), + ))); + } + } + + for (column_index, column) in self.table.columns.iter().enumerate() { + let column = column.borrow(); + fragments.push(Fragment::Positioning(PositioningFragment::new_empty( + column.base.base_fragment_info, + dimensions.get_column_rect(column_index).as_physical(None), + column.base.style.clone(), + ))); + } + } + + fn compute_border_collapse(&mut self, writing_mode: WritingMode) { + if self.table.style.get_inherited_table().border_collapse != BorderCollapse::Collapse { + self.collapsed_borders = None; + return; + } + + let mut collapsed_borders = LogicalVec2 { + block: vec![ + vec![Default::default(); self.table.size.width]; + self.table.size.height + 1 + ], + inline: vec![ + vec![Default::default(); self.table.size.height]; + self.table.size.width + 1 + ], + }; + + let apply_border = |collapsed_borders: &mut CollapsedBorders, + layout_style: &LayoutStyle, + block: &Range<usize>, + inline: &Range<usize>| { + let border = CollapsedBorder::from_layout_style(layout_style, writing_mode); + border + .block_start + .max_assign_to_slice(&mut collapsed_borders.block[block.start][inline.clone()]); + border + .block_end + .max_assign_to_slice(&mut collapsed_borders.block[block.end][inline.clone()]); + border + .inline_start + .max_assign_to_slice(&mut collapsed_borders.inline[inline.start][block.clone()]); + border + .inline_end + .max_assign_to_slice(&mut collapsed_borders.inline[inline.end][block.clone()]); + }; + let hide_inner_borders = |collapsed_borders: &mut CollapsedBorders, + block: &Range<usize>, + inline: &Range<usize>| { + for x in inline.clone() { + for y in block.clone() { + if x != inline.start { + collapsed_borders.inline[x][y].hide(); + } + if y != block.start { + collapsed_borders.block[y][x].hide(); + } + } + } + }; + let all_rows = 0..self.table.size.height; + let all_columns = 0..self.table.size.width; + for row_index in all_rows.clone() { + for column_index in all_columns.clone() { + let cell = match self.table.slots[row_index][column_index] { + TableSlot::Cell(ref cell) => cell, + _ => continue, + } + .borrow(); + let block_range = row_index..row_index + cell.rowspan; + let inline_range = column_index..column_index + cell.colspan; + hide_inner_borders(&mut collapsed_borders, &block_range, &inline_range); + apply_border( + &mut collapsed_borders, + &cell.layout_style(), + &block_range, + &inline_range, + ); + } + } + for (row_index, row) in self.table.rows.iter().enumerate() { + let row = row.borrow(); + apply_border( + &mut collapsed_borders, + &row.layout_style(), + &(row_index..row_index + 1), + &all_columns, + ); + } + for row_group in &self.table.row_groups { + let row_group = row_group.borrow(); + apply_border( + &mut collapsed_borders, + &row_group.layout_style(), + &row_group.track_range, + &all_columns, + ); + } + for (column_index, column) in self.table.columns.iter().enumerate() { + let column = column.borrow(); + apply_border( + &mut collapsed_borders, + &column.layout_style(), + &all_rows, + &(column_index..column_index + 1), + ); + } + for column_group in &self.table.column_groups { + let column_group = column_group.borrow(); + apply_border( + &mut collapsed_borders, + &column_group.layout_style(), + &all_rows, + &column_group.track_range, + ); + } + apply_border( + &mut collapsed_borders, + &self.table.layout_style_for_grid(), + &all_rows, + &all_columns, + ); + + self.collapsed_borders = Some(collapsed_borders); + } + + fn get_collapsed_border_widths_for_area( + &self, + area: LogicalSides<usize>, + ) -> Option<LogicalSides<Au>> { + let collapsed_borders = self.collapsed_borders.as_ref()?; + let columns = || area.inline_start..area.inline_end; + let rows = || area.block_start..area.block_end; + let max_width = |slice: &[CollapsedBorder]| { + let slice_widths = slice.iter().map(|collapsed_border| collapsed_border.width); + slice_widths.max().unwrap_or_default() + }; + Some(area.map_inline_and_block_axes( + |column| max_width(&collapsed_borders.inline[*column][rows()]) / 2, + |row| max_width(&collapsed_borders.block[*row][columns()]) / 2, + )) + } +} + +struct RowFragmentLayout<'a> { + row: &'a TableTrack, + rect: LogicalRect<Au>, + containing_block: ContainingBlock<'a>, + positioning_context: Option<PositioningContext>, + fragments: Vec<Fragment>, +} + +impl<'a> RowFragmentLayout<'a> { + fn new( + table_row: &'a TableTrack, + index: usize, + dimensions: &TableAndTrackDimensions, + table_style: &'a ComputedValues, + ) -> Self { + let rect = dimensions.get_row_rect(index); + let containing_block = ContainingBlock { + size: ContainingBlockSize { + inline: rect.size.inline, + block: SizeConstraint::Definite(rect.size.block), + }, + style: table_style, + }; + Self { + row: table_row, + rect, + positioning_context: PositioningContext::new_for_style(&table_row.base.style), + containing_block, + fragments: Vec::new(), + } + } + fn finish( + mut self, + layout_context: &LayoutContext, + table_positioning_context: &mut PositioningContext, + containing_block_for_logical_conversion: &ContainingBlock, + containing_block_for_children: &ContainingBlock, + row_group_fragment_layout: &mut Option<RowGroupFragmentLayout>, + ) -> Fragment { + if self.positioning_context.is_some() { + self.rect.start_corner += + relative_adjustement(&self.row.base.style, containing_block_for_children); + } + + let (inline_size, block_size) = if let Some(row_group_layout) = row_group_fragment_layout { + self.rect.start_corner -= row_group_layout.rect.start_corner; + ( + row_group_layout.rect.size.inline, + SizeConstraint::Definite(row_group_layout.rect.size.block), + ) + } else { + ( + containing_block_for_logical_conversion.size.inline, + containing_block_for_logical_conversion.size.block, + ) + }; + + let row_group_containing_block = ContainingBlock { + size: ContainingBlockSize { + inline: inline_size, + block: block_size, + }, + style: containing_block_for_logical_conversion.style, + }; + + let mut row_fragment = BoxFragment::new( + self.row.base.base_fragment_info, + self.row.base.style.clone(), + self.fragments, + self.rect.as_physical(Some(&row_group_containing_block)), + PhysicalSides::zero(), /* padding */ + PhysicalSides::zero(), /* border */ + PhysicalSides::zero(), /* margin */ + None, /* clearance */ + ); + row_fragment.set_does_not_paint_background(); + + if let Some(mut row_positioning_context) = self.positioning_context.take() { + row_positioning_context.layout_collected_children(layout_context, &mut row_fragment); + + let positioning_context = row_group_fragment_layout + .as_mut() + .and_then(|layout| layout.positioning_context.as_mut()) + .unwrap_or(table_positioning_context); + positioning_context.append(row_positioning_context); + } + + let fragment = Fragment::Box(ArcRefCell::new(row_fragment)); + self.row.base.set_fragment(fragment.clone()); + fragment + } +} + +struct RowGroupFragmentLayout { + row_group: ArcRefCell<TableTrackGroup>, + rect: LogicalRect<Au>, + positioning_context: Option<PositioningContext>, + index: usize, + fragments: Vec<Fragment>, +} + +impl RowGroupFragmentLayout { + fn new( + row_group: ArcRefCell<TableTrackGroup>, + index: usize, + dimensions: &TableAndTrackDimensions, + ) -> Self { + let (rect, positioning_context) = { + let row_group = row_group.borrow(); + ( + dimensions.get_row_group_rect(&row_group), + PositioningContext::new_for_style(&row_group.base.style), + ) + }; + Self { + row_group, + rect, + positioning_context, + index, + fragments: Vec::new(), + } + } + + fn finish( + mut self, + layout_context: &LayoutContext, + table_positioning_context: &mut PositioningContext, + containing_block_for_logical_conversion: &ContainingBlock, + containing_block_for_children: &ContainingBlock, + ) -> Fragment { + let row_group = self.row_group.borrow(); + if self.positioning_context.is_some() { + self.rect.start_corner += + relative_adjustement(&row_group.base.style, containing_block_for_children); + } + + let mut row_group_fragment = BoxFragment::new( + row_group.base.base_fragment_info, + row_group.base.style.clone(), + self.fragments, + self.rect + .as_physical(Some(containing_block_for_logical_conversion)), + PhysicalSides::zero(), /* padding */ + PhysicalSides::zero(), /* border */ + PhysicalSides::zero(), /* margin */ + None, /* clearance */ + ); + row_group_fragment.set_does_not_paint_background(); + + if let Some(mut row_positioning_context) = self.positioning_context.take() { + row_positioning_context + .layout_collected_children(layout_context, &mut row_group_fragment); + table_positioning_context.append(row_positioning_context); + } + + let fragment = Fragment::Box(ArcRefCell::new(row_group_fragment)); + row_group.base.set_fragment(fragment.clone()); + fragment + } +} + +struct TableAndTrackDimensions { + /// The rect of the full table, not counting for borders, padding, and margin. + table_rect: LogicalRect<Au>, + /// The rect of the full table, not counting for borders, padding, and margin + /// and offset by any border spacing and caption. + table_cells_rect: LogicalRect<Au>, + /// The min and max block offsets of each table row. + row_dimensions: Vec<(Au, Au)>, + /// The min and max inline offsets of each table column + column_dimensions: Vec<(Au, Au)>, +} + +impl TableAndTrackDimensions { + fn new(table_layout: &TableLayout) -> Self { + let border_spacing = table_layout.table.border_spacing(); + + // The sizes used for a dimension when that dimension has no table tracks. + let fallback_inline_size = table_layout.assignable_width; + let fallback_block_size = table_layout.final_table_height; + + let mut column_dimensions = Vec::new(); + let mut column_offset = Au::zero(); + for column_index in 0..table_layout.table.size.width { + if table_layout.is_column_collapsed(column_index) { + column_dimensions.push((column_offset, column_offset)); + continue; + } + let start_offset = column_offset + border_spacing.inline; + let end_offset = start_offset + table_layout.distributed_column_widths[column_index]; + column_dimensions.push((start_offset, end_offset)); + column_offset = end_offset; + } + column_offset += if table_layout.table.size.width == 0 { + fallback_inline_size + } else { + border_spacing.inline + }; + + let mut row_dimensions = Vec::new(); + let mut row_offset = Au::zero(); + for row_index in 0..table_layout.table.size.height { + if table_layout.is_row_collapsed(row_index) { + row_dimensions.push((row_offset, row_offset)); + continue; + } + let start_offset = row_offset + border_spacing.block; + let end_offset = start_offset + table_layout.row_sizes[row_index]; + row_dimensions.push((start_offset, end_offset)); + row_offset = end_offset; + } + row_offset += if table_layout.table.size.height == 0 { + fallback_block_size + } else { + border_spacing.block + }; + + let table_start_corner = LogicalVec2 { + inline: column_dimensions.first().map_or_else(Au::zero, |v| v.0), + block: row_dimensions.first().map_or_else(Au::zero, |v| v.0), + }; + let table_size = LogicalVec2 { + inline: column_dimensions + .last() + .map_or(fallback_inline_size, |v| v.1), + block: row_dimensions.last().map_or(fallback_block_size, |v| v.1), + } - table_start_corner; + let table_cells_rect = LogicalRect { + start_corner: table_start_corner, + size: table_size, + }; + + let table_rect = LogicalRect { + start_corner: LogicalVec2::zero(), + size: LogicalVec2 { + inline: column_offset, + block: row_offset, + }, + }; + + Self { + table_rect, + table_cells_rect, + row_dimensions, + column_dimensions, + } + } + + fn get_row_rect(&self, row_index: usize) -> LogicalRect<Au> { + let mut row_rect = self.table_cells_rect; + let row_dimensions = self.row_dimensions[row_index]; + row_rect.start_corner.block = row_dimensions.0; + row_rect.size.block = row_dimensions.1 - row_dimensions.0; + row_rect + } + + fn get_column_rect(&self, column_index: usize) -> LogicalRect<Au> { + let mut row_rect = self.table_cells_rect; + let column_dimensions = self.column_dimensions[column_index]; + row_rect.start_corner.inline = column_dimensions.0; + row_rect.size.inline = column_dimensions.1 - column_dimensions.0; + row_rect + } + + fn get_row_group_rect(&self, row_group: &TableTrackGroup) -> LogicalRect<Au> { + if row_group.is_empty() { + return LogicalRect::zero(); + } + + let mut row_group_rect = self.table_cells_rect; + let block_start = self.row_dimensions[row_group.track_range.start].0; + let block_end = self.row_dimensions[row_group.track_range.end - 1].1; + row_group_rect.start_corner.block = block_start; + row_group_rect.size.block = block_end - block_start; + row_group_rect + } + + fn get_column_group_rect(&self, column_group: &TableTrackGroup) -> LogicalRect<Au> { + if column_group.is_empty() { + return LogicalRect::zero(); + } + + let mut column_group_rect = self.table_cells_rect; + let inline_start = self.column_dimensions[column_group.track_range.start].0; + let inline_end = self.column_dimensions[column_group.track_range.end - 1].1; + column_group_rect.start_corner.inline = inline_start; + column_group_rect.size.inline = inline_end - inline_start; + column_group_rect + } + + fn get_cell_rect( + &self, + coordinates: TableSlotCoordinates, + rowspan: usize, + colspan: usize, + ) -> LogicalRect<Au> { + let start_corner = LogicalVec2 { + inline: self.column_dimensions[coordinates.x].0, + block: self.row_dimensions[coordinates.y].0, + }; + let size = LogicalVec2 { + inline: self.column_dimensions[coordinates.x + colspan - 1].1, + block: self.row_dimensions[coordinates.y + rowspan - 1].1, + } - start_corner; + LogicalRect { start_corner, size } + } +} + +impl Table { + fn border_spacing(&self) -> LogicalVec2<Au> { + if self.style.clone_border_collapse() == BorderCollapse::Collapse { + LogicalVec2::zero() + } else { + let border_spacing = self.style.clone_border_spacing(); + LogicalVec2 { + inline: border_spacing.horizontal(), + block: border_spacing.vertical(), + } + } + } + + fn total_border_spacing(&self) -> LogicalVec2<Au> { + let border_spacing = self.border_spacing(); + LogicalVec2 { + inline: if self.size.width > 0 { + border_spacing.inline * (self.size.width as i32 + 1) + } else { + Au::zero() + }, + block: if self.size.height > 0 { + border_spacing.block * (self.size.height as i32 + 1) + } else { + Au::zero() + }, + } + } + + fn get_column_measure_for_column_at_index( + &self, + writing_mode: WritingMode, + column_index: usize, + is_in_fixed_mode: bool, + ) -> CellOrTrackMeasure { + let column = match self.columns.get(column_index) { + Some(column) => column, + None => return CellOrTrackMeasure::zero(), + } + .borrow(); + + let CellOrColumnOuterSizes { + preferred: preferred_size, + min: min_size, + max: max_size, + percentage: percentage_size, + } = CellOrColumnOuterSizes::new( + &column.base.style, + writing_mode, + &Default::default(), + is_in_fixed_mode, + ); + + CellOrTrackMeasure { + content_sizes: ContentSizes { + // > The outer min-content width of a table-column or table-column-group is + // > max(min-width, width). + // But that's clearly wrong, since it would be equal to or greater than + // the outer max-content width. So we match other browsers instead. + min_content: min_size.inline, + // > The outer max-content width of a table-column or table-column-group is + // > max(min-width, min(max-width, width)). + // This matches Gecko, but Blink and WebKit ignore max_size. + max_content: preferred_size + .inline + .clamp_between_extremums(min_size.inline, max_size.inline), + }, + percentage: percentage_size.inline, + } + } + + fn get_row_measure_for_row_at_index( + &self, + writing_mode: WritingMode, + row_index: usize, + ) -> CellOrTrackMeasure { + let row = match self.rows.get(row_index) { + Some(row) => row, + None => return CellOrTrackMeasure::zero(), + }; + + // In the block axis, the min-content and max-content sizes are the same + // (except for new layout boxes like grid and flex containers). Note that + // other browsers don't seem to use the min and max sizing properties here. + let row = row.borrow(); + let size = row.base.style.box_size(writing_mode); + let max_size = row.base.style.max_box_size(writing_mode); + let percentage_contribution = get_size_percentage_contribution(&size, &max_size); + + CellOrTrackMeasure { + content_sizes: size + .block + .to_numeric() + .and_then(|size| size.to_length()) + .map_or_else(Au::zero, Au::from) + .into(), + percentage: percentage_contribution.block, + } + } + + pub(crate) fn layout( + &self, + layout_context: &LayoutContext, + positioning_context: &mut PositioningContext, + containing_block_for_children: &ContainingBlock, + containing_block_for_table: &ContainingBlock, + depends_on_block_constraints: bool, + ) -> CacheableLayoutResult { + TableLayout::new(self).layout( + layout_context, + positioning_context, + containing_block_for_children, + containing_block_for_table, + depends_on_block_constraints, + ) + } +} + +impl ComputeInlineContentSizes for Table { + #[cfg_attr( + feature = "tracing", + tracing::instrument( + name = "Table::compute_inline_content_sizes", + skip_all, + fields(servo_profiling = true), + level = "trace", + ) + )] + fn compute_inline_content_sizes( + &self, + layout_context: &LayoutContext, + constraint_space: &ConstraintSpace, + ) -> InlineContentSizesResult { + let writing_mode = constraint_space.writing_mode; + let mut layout = TableLayout::new(self); + layout.compute_border_collapse(writing_mode); + layout.pbm = self + .layout_style(Some(&layout)) + .padding_border_margin_with_writing_mode_and_containing_block_inline_size( + writing_mode, + Au::zero(), + ); + layout.compute_measures(layout_context, writing_mode); + + let grid_content_sizes = layout.compute_grid_min_max(); + + // Padding and border should apply to the table grid, but they will be taken into + // account when computing the inline content sizes of the table wrapper (our parent), so + // this code removes their contribution from the inline content size of the caption. + let caption_content_sizes = ContentSizes::from( + layout.compute_caption_minimum_inline_size(layout_context) - + layout.pbm.padding_border_sums.inline, + ); + + InlineContentSizesResult { + sizes: grid_content_sizes.max(caption_content_sizes), + depends_on_block_constraints: false, + } + } +} + +impl Table { + #[inline] + pub(crate) fn layout_style<'a>( + &'a self, + layout: Option<&'a TableLayout<'a>>, + ) -> LayoutStyle<'a> { + LayoutStyle::Table(TableLayoutStyle { + table: self, + layout, + }) + } + + #[inline] + pub(crate) fn layout_style_for_grid(&self) -> LayoutStyle { + LayoutStyle::Default(&self.grid_style) + } +} + +impl TableTrack { + #[inline] + pub(crate) fn layout_style(&self) -> LayoutStyle { + LayoutStyle::Default(&self.base.style) + } +} + +impl TableTrackGroup { + #[inline] + pub(crate) fn layout_style(&self) -> LayoutStyle { + LayoutStyle::Default(&self.base.style) + } +} + +impl TableLayoutStyle<'_> { + #[inline] + pub(crate) fn style(&self) -> &ComputedValues { + &self.table.style + } + + #[inline] + pub(crate) fn collapses_borders(&self) -> bool { + self.style().get_inherited_table().border_collapse == BorderCollapse::Collapse + } + + pub(crate) fn halved_collapsed_border_widths(&self) -> LogicalSides<Au> { + debug_assert!(self.collapses_borders()); + let area = LogicalSides { + inline_start: 0, + inline_end: self.table.size.width, + block_start: 0, + block_end: self.table.size.height, + }; + if let Some(layout) = self.layout { + layout.get_collapsed_border_widths_for_area(area) + } else { + // TODO: this should be cached. + let mut layout = TableLayout::new(self.table); + layout.compute_border_collapse(self.style().writing_mode); + layout.get_collapsed_border_widths_for_area(area) + } + .expect("Collapsed borders should be computed") + } +} + +impl TableSlotCell { + #[inline] + fn layout_style(&self) -> LayoutStyle { + self.contents.layout_style(&self.base) + } + + fn effective_vertical_align(&self) -> VerticalAlignKeyword { + match self.base.style.clone_vertical_align() { + VerticalAlign::Keyword(VerticalAlignKeyword::Top) => VerticalAlignKeyword::Top, + VerticalAlign::Keyword(VerticalAlignKeyword::Bottom) => VerticalAlignKeyword::Bottom, + VerticalAlign::Keyword(VerticalAlignKeyword::Middle) => VerticalAlignKeyword::Middle, + _ => VerticalAlignKeyword::Baseline, + } + } + + fn inline_content_sizes(&self, layout_context: &LayoutContext) -> ContentSizes { + let constraint_space = ConstraintSpace::new_for_style_and_ratio( + &self.base.style, + None, /* TODO: support preferred aspect ratios on non-replaced boxes */ + ); + self.base + .inline_content_sizes(layout_context, &constraint_space, &self.contents.contents) + .sizes + } + + fn create_fragment( + &self, + mut layout: CellLayout, + cell_rect: LogicalRect<Au>, + cell_baseline: Au, + positioning_context: &mut PositioningContext, + table_style: &ComputedValues, + containing_block: &ContainingBlock, + ) -> BoxFragment { + // This must be scoped to this function because it conflicts with euclid's Zero. + use style::Zero as StyleZero; + + let cell_content_rect = cell_rect.deflate(&(layout.padding + layout.border)); + let content_block_size = layout.layout.content_block_size; + let vertical_align_offset = match self.effective_vertical_align() { + VerticalAlignKeyword::Top => Au::zero(), + VerticalAlignKeyword::Bottom => cell_content_rect.size.block - content_block_size, + VerticalAlignKeyword::Middle => { + (cell_content_rect.size.block - content_block_size).scale_by(0.5) + }, + _ => { + cell_baseline - + (layout.padding.block_start + layout.border.block_start) - + layout.ascent() + }, + }; + + let mut base_fragment_info = self.base.base_fragment_info; + if self.base.style.get_inherited_table().empty_cells == EmptyCells::Hide && + table_style.get_inherited_table().border_collapse != BorderCollapse::Collapse && + layout.is_empty_for_empty_cells() + { + base_fragment_info.flags.insert(FragmentFlags::DO_NOT_PAINT); + } + + // Create an `AnonymousFragment` to move the cell contents to the cell baseline. + let mut vertical_align_fragment_rect = cell_content_rect; + vertical_align_fragment_rect.start_corner = LogicalVec2 { + inline: Au::zero(), + block: vertical_align_offset, + }; + let vertical_align_fragment = PositioningFragment::new_anonymous( + vertical_align_fragment_rect.as_physical(None), + layout.layout.fragments, + ); + + // Adjust the static position of all absolute children based on the + // final content rect of this fragment. Note that we are not shifting by the position of the + // Anonymous fragment we use to shift content to the baseline. + // + // TODO(mrobinson): This is correct for absolutes that are direct children of the table + // cell, but wrong for absolute fragments that are more deeply nested in the hierarchy of + // fragments. + let physical_cell_rect = cell_content_rect.as_physical(Some(containing_block)); + layout + .positioning_context + .adjust_static_position_of_hoisted_fragments_with_offset( + &physical_cell_rect.origin.to_vector(), + PositioningContextLength::zero(), + ); + positioning_context.append(layout.positioning_context); + + let specific_layout_info = (table_style.get_inherited_table().border_collapse == + BorderCollapse::Collapse) + .then_some(SpecificLayoutInfo::TableCellWithCollapsedBorders); + + BoxFragment::new( + base_fragment_info, + self.base.style.clone(), + vec![Fragment::Positioning(vertical_align_fragment)], + physical_cell_rect, + layout.padding.to_physical(table_style.writing_mode), + layout.border.to_physical(table_style.writing_mode), + PhysicalSides::zero(), /* margin */ + None, /* clearance */ + ) + .with_baselines(layout.layout.baselines) + .with_specific_layout_info(specific_layout_info) + } +} + +fn get_size_percentage_contribution( + size: &LogicalVec2<Size<ComputedLengthPercentage>>, + max_size: &LogicalVec2<Size<ComputedLengthPercentage>>, +) -> LogicalVec2<Option<Percentage>> { + // From <https://drafts.csswg.org/css-tables/#percentage-contribution> + // > The percentage contribution of a table cell, column, or column group is defined + // > in terms of the computed values of width and max-width that have computed values + // > that are percentages: + // > min(percentage width, percentage max-width). + // > If the computed values are not percentages, then 0% is used for width, and an + // > infinite percentage is used for max-width. + LogicalVec2 { + inline: max_two_optional_percentages( + size.inline.to_percentage(), + max_size.inline.to_percentage(), + ), + block: max_two_optional_percentages( + size.block.to_percentage(), + max_size.block.to_percentage(), + ), + } +} + +struct CellOrColumnOuterSizes { + min: LogicalVec2<Au>, + preferred: LogicalVec2<Au>, + max: LogicalVec2<Option<Au>>, + percentage: LogicalVec2<Option<Percentage>>, +} + +impl CellOrColumnOuterSizes { + fn new( + style: &Arc<ComputedValues>, + writing_mode: WritingMode, + padding_border_sums: &LogicalVec2<Au>, + is_in_fixed_mode: bool, + ) -> Self { + let box_sizing = style.get_position().box_sizing; + let outer_size = |size: LogicalVec2<Au>| match box_sizing { + BoxSizing::ContentBox => size + *padding_border_sums, + BoxSizing::BorderBox => LogicalVec2 { + inline: size.inline.max(padding_border_sums.inline), + block: size.block.max(padding_border_sums.block), + }, + }; + + let outer_option_size = |size: LogicalVec2<Option<Au>>| match box_sizing { + BoxSizing::ContentBox => size.map_inline_and_block_axes( + |inline| inline.map(|inline| inline + padding_border_sums.inline), + |block| block.map(|block| block + padding_border_sums.block), + ), + BoxSizing::BorderBox => size.map_inline_and_block_axes( + |inline| inline.map(|inline| inline.max(padding_border_sums.inline)), + |block| block.map(|block| block.max(padding_border_sums.block)), + ), + }; + + let get_size_for_axis = |size: &Size<ComputedLengthPercentage>| { + // Note that measures treat all size values other than <length> + // as the initial value of the property. + size.to_numeric() + .and_then(|length_percentage| length_percentage.to_length()) + .map(Au::from) + }; + + let size = style.box_size(writing_mode); + if is_in_fixed_mode { + return Self { + percentage: size.map(|v| v.to_percentage()), + preferred: outer_option_size(size.map(get_size_for_axis)) + .map(|v| v.unwrap_or_default()), + min: LogicalVec2::default(), + max: LogicalVec2::default(), + }; + } + + let min_size = style.min_box_size(writing_mode); + let max_size = style.max_box_size(writing_mode); + + Self { + min: outer_size(min_size.map(|v| get_size_for_axis(v).unwrap_or_default())), + preferred: outer_size(size.map(|v| get_size_for_axis(v).unwrap_or_default())), + max: outer_option_size(max_size.map(get_size_for_axis)), + percentage: get_size_percentage_contribution(&size, &max_size), + } + } +} + +struct RowspanToDistribute<'a> { + coordinates: TableSlotCoordinates, + cell: AtomicRef<'a, TableSlotCell>, + measure: &'a CellOrTrackMeasure, +} + +impl RowspanToDistribute<'_> { + fn range(&self) -> Range<usize> { + self.coordinates.y..self.coordinates.y + self.cell.rowspan + } + + fn fully_encloses(&self, other: &RowspanToDistribute) -> bool { + other.coordinates.y > self.coordinates.y && other.range().end < self.range().end + } +} + +/// The inline size constraints provided by a cell that span multiple columns (`colspan` > 1). +/// These constraints are distributed to the individual columns that make up this cell's span. +#[derive(Debug)] +struct ColspanToDistribute { + starting_column: usize, + span: usize, + content_sizes: ContentSizes, + percentage: Option<Percentage>, +} + +impl ColspanToDistribute { + /// A comparison function to sort the colspan cell constraints primarily by their span + /// width and secondarily by their starting column. This is not an implementation of + /// `PartialOrd` because we want to return [`Ordering::Equal`] even if `self != other`. + fn comparison_for_sort(a: &Self, b: &Self) -> Ordering { + a.span + .cmp(&b.span) + .then_with(|| b.starting_column.cmp(&b.starting_column)) + } + + fn range(&self) -> Range<usize> { + self.starting_column..self.starting_column + self.span + } +} |