layout: Implement most of border-collapse per CSS 2.1 § 17.6.2.

Known issues:

* Collapsed borders do not correctly affect the border-box of the table
  itself.

* The content widths of all cells in a column and the content height of
  all cells in a row is the same in this patch, but not in Gecko and
  WebKit.

* Corners are not painted well. The spec does not say what to do here.

* Column spans are not handled well. The spec does not say what to do
  here either.
This commit is contained in:
Patrick Walton 2015-03-09 12:33:04 -07:00 committed by Simon Sapin
parent 92359c7b9a
commit 48299a53cb
22 changed files with 1975 additions and 520 deletions

View file

@ -9,6 +9,7 @@
use block::{self, BlockFlow, CandidateBSizeIterator, ISizeAndMarginsComputer};
use block::{ISizeConstraintInput, ISizeConstraintSolution};
use context::LayoutContext;
use display_list_builder::{BlockFlowDisplayListBuilding, BorderPaintingMode};
use floats::FloatKind;
use flow::{self, Flow, FlowClass, IMPACTED_BY_LEFT_FLOATS, IMPACTED_BY_RIGHT_FLOATS};
use flow::{ImmutableFlowUtils};
@ -16,20 +17,23 @@ use fragment::{Fragment, FragmentBorderBoxIterator};
use incremental::{REFLOW, REFLOW_OUT_OF_FLOW};
use layout_debug;
use model::{IntrinsicISizes, IntrinsicISizesContribution, MaybeAuto};
use table_row::CellIntrinsicInlineSize;
use table_row::{self, CellIntrinsicInlineSize, CollapsedBorder, CollapsedBorderProvenance};
use table_row::{TableRowFlow};
use table_wrapper::TableLayout;
use wrapper::ThreadSafeLayoutNode;
use geom::{Point2D, Rect};
use std::cmp::max;
use gfx::display_list::DisplayList;
use std::cmp;
use std::fmt;
use std::iter;
use std::sync::Arc;
use style::computed_values::{border_collapse, border_spacing, table_layout};
use style::properties::ComputedValues;
use style::values::CSSFloat;
use style::values::computed::LengthOrPercentageOrAuto;
use util::geometry::Au;
use util::logical_geometry::{LogicalRect, WritingMode};
use util::logical_geometry::LogicalRect;
/// A table flow corresponded to the table's internal table fragment under a table wrapper flow.
/// The properties `position`, `float`, and `margin-*` are used on the table wrapper fragment,
@ -42,10 +46,18 @@ pub struct TableFlow {
/// intrinsic inline-size bubbling.
pub column_intrinsic_inline_sizes: Vec<ColumnIntrinsicInlineSize>,
/// Information about the actual inline-sizes of each column, computed top-down during actual
/// Information about the actual inline sizes of each column, computed top-down during actual
/// inline-size bubbling.
pub column_computed_inline_sizes: Vec<ColumnComputedInlineSize>,
/// The final width of the borders in the inline direction for each cell, computed by the
/// entire table and pushed down into each row during inline size computation.
pub collapsed_inline_direction_border_widths_for_table: Vec<Au>,
/// The final width of the borders in the block direction for each cell, computed by the
/// entire table and pushed down into each row during inline size computation.
pub collapsed_block_direction_border_widths_for_table: Vec<Au>,
/// Table-layout property
pub table_layout: TableLayout,
}
@ -65,6 +77,8 @@ impl TableFlow {
block_flow: block_flow,
column_intrinsic_inline_sizes: Vec::new(),
column_computed_inline_sizes: Vec::new(),
collapsed_inline_direction_border_widths_for_table: Vec::new(),
collapsed_block_direction_border_widths_for_table: Vec::new(),
table_layout: table_layout
}
}
@ -84,6 +98,8 @@ impl TableFlow {
block_flow: block_flow,
column_intrinsic_inline_sizes: Vec::new(),
column_computed_inline_sizes: Vec::new(),
collapsed_inline_direction_border_widths_for_table: Vec::new(),
collapsed_block_direction_border_widths_for_table: Vec::new(),
table_layout: table_layout
}
}
@ -109,10 +125,10 @@ impl TableFlow {
} else {
let column_size = &child_cell_inline_size.column_size;
*parent_sizes = ColumnIntrinsicInlineSize {
minimum_length: max(parent_sizes.minimum_length,
column_size.minimum_length),
minimum_length: cmp::max(parent_sizes.minimum_length,
column_size.minimum_length),
percentage: parent_sizes.greatest_percentage(column_size),
preferred: max(parent_sizes.preferred, column_size.preferred),
preferred: cmp::max(parent_sizes.preferred, column_size.preferred),
constrained: parent_sizes.constrained || column_size.constrained,
}
}
@ -146,7 +162,7 @@ impl TableFlow {
fn update_column_inline_sizes_for_row(child: &mut Flow,
column_inline_sizes: &mut Vec<ColumnIntrinsicInlineSize>,
computation: &mut IntrinsicISizesContribution,
did_first_row: &mut bool,
first_row: bool,
table_layout: TableLayout) {
// Read column inline-sizes from the table-row, and assign inline-size=0 for the columns
// not defined in the column group.
@ -159,8 +175,7 @@ impl TableFlow {
// Fixed table layout only looks at the first row.
//
// FIXME(pcwalton): This is really inefficient. We should stop after the first row!
if !*did_first_row {
*did_first_row = true;
if first_row {
for cell_inline_size in row.cell_intrinsic_inline_sizes.iter() {
column_inline_sizes.push(cell_inline_size.column_size);
}
@ -175,7 +190,7 @@ impl TableFlow {
}
/// Returns the effective spacing per cell, taking the value of `border-collapse` into account.
fn spacing(&self) -> border_spacing::T {
pub fn spacing(&self) -> border_spacing::T {
let style = self.block_flow.fragment.style();
match style.get_inheritedtable().border_collapse {
border_collapse::T::separate => style.get_inheritedtable().border_spacing,
@ -206,6 +221,10 @@ impl Flow for TableFlow {
&mut self.block_flow
}
fn as_immutable_block(&self) -> &BlockFlow {
&self.block_flow
}
fn column_intrinsic_inline_sizes<'a>(&'a mut self) -> &'a mut Vec<ColumnIntrinsicInlineSize> {
&mut self.column_intrinsic_inline_sizes
}
@ -224,50 +243,165 @@ impl Flow for TableFlow {
// Don't use `compute_intrinsic_inline_sizes` here because that will count padding as
// part of the table, which we don't want to do—it belongs to the table wrapper instead.
self.collapsed_inline_direction_border_widths_for_table = Vec::new();
self.collapsed_block_direction_border_widths_for_table = vec![Au(0)];
let collapsing_borders = self.block_flow
.fragment
.style
.get_inheritedtable()
.border_collapse == border_collapse::T::collapse;
let table_inline_collapsed_borders = if collapsing_borders {
Some(TableInlineCollapsedBorders {
start: CollapsedBorder::inline_start(&*self.block_flow.fragment.style,
CollapsedBorderProvenance::FromTable),
end: CollapsedBorder::inline_end(&*self.block_flow.fragment.style,
CollapsedBorderProvenance::FromTable),
})
} else {
None
};
let mut computation = IntrinsicISizesContribution::new();
let mut did_first_row = false;
for kid in self.block_flow.base.child_iter() {
debug_assert!(kid.is_proper_table_child());
if kid.is_table_colgroup() {
for specified_inline_size in kid.as_table_colgroup().inline_sizes.iter() {
self.column_intrinsic_inline_sizes.push(ColumnIntrinsicInlineSize {
minimum_length: match *specified_inline_size {
LengthOrPercentageOrAuto::Auto | LengthOrPercentageOrAuto::Percentage(_) => Au(0),
LengthOrPercentageOrAuto::Length(length) => length,
},
percentage: match *specified_inline_size {
LengthOrPercentageOrAuto::Auto | LengthOrPercentageOrAuto::Length(_) => 0.0,
LengthOrPercentageOrAuto::Percentage(percentage) => percentage,
},
preferred: Au(0),
constrained: false,
})
}
} else if kid.is_table_rowgroup() {
for grandkid in flow::mut_base(kid).child_iter() {
let mut previous_collapsed_block_end_borders = if collapsing_borders {
PreviousBlockCollapsedBorders::FromTable(CollapsedBorder::block_start(
&*self.block_flow.fragment.style,
CollapsedBorderProvenance::FromTable))
} else {
PreviousBlockCollapsedBorders::NotCollapsingBorders
};
let mut first_row = true;
{
let mut iterator = self.block_flow.base.child_iter().peekable();
while let Some(kid) = iterator.next() {
let next_index_and_sibling = iterator.peek();
let next_collapsed_borders_in_block_direction = if collapsing_borders {
match next_index_and_sibling {
Some(next_sibling) => {
if next_sibling.is_table_rowgroup() {
NextBlockCollapsedBorders::FromNextRow(
&next_sibling.as_immutable_table_rowgroup()
.preliminary_collapsed_borders
.block_start
.as_slice())
} else {
NextBlockCollapsedBorders::FromNextRow(
&next_sibling.as_immutable_table_row()
.preliminary_collapsed_borders
.block_start
.as_slice())
}
}
None => {
NextBlockCollapsedBorders::FromTable(
CollapsedBorder::block_end(&*self.block_flow.fragment.style,
CollapsedBorderProvenance::FromTable))
}
}
} else {
NextBlockCollapsedBorders::NotCollapsingBorders
};
if kid.is_table_colgroup() {
for specified_inline_size in kid.as_table_colgroup().inline_sizes.iter() {
self.column_intrinsic_inline_sizes.push(ColumnIntrinsicInlineSize {
minimum_length: match *specified_inline_size {
LengthOrPercentageOrAuto::Auto |
LengthOrPercentageOrAuto::Percentage(_) => Au(0),
LengthOrPercentageOrAuto::Length(length) => length,
},
percentage: match *specified_inline_size {
LengthOrPercentageOrAuto::Auto |
LengthOrPercentageOrAuto::Length(_) => 0.0,
LengthOrPercentageOrAuto::Percentage(percentage) => percentage,
},
preferred: Au(0),
constrained: false,
})
}
} else if kid.is_table_row() {
TableFlow::update_column_inline_sizes_for_row(
grandkid,
&mut self.column_intrinsic_inline_sizes,
&mut computation,
&mut did_first_row,
self.table_layout)
kid,
&mut self.column_intrinsic_inline_sizes,
&mut computation,
first_row,
self.table_layout);
if collapsing_borders {
perform_border_collapse_for_row(
kid.as_table_row(),
table_inline_collapsed_borders.as_ref().unwrap(),
previous_collapsed_block_end_borders,
next_collapsed_borders_in_block_direction,
&mut self.collapsed_inline_direction_border_widths_for_table,
&mut self.collapsed_block_direction_border_widths_for_table);
previous_collapsed_block_end_borders =
PreviousBlockCollapsedBorders::FromPreviousRow(
kid.as_table_row().final_collapsed_borders.block_end.clone())
}
first_row = false
} else if kid.is_table_rowgroup() {
let mut iterator = flow::mut_base(kid).child_iter().peekable();
while let Some(grandkid) = iterator.next() {
let grandkid_next_sibling = iterator.peek();
let next_collapsed_borders_in_block_direction = if collapsing_borders {
match grandkid_next_sibling {
Some(grandkid_next_sibling) => {
if grandkid_next_sibling.is_table_rowgroup() {
NextBlockCollapsedBorders::FromNextRow(
&grandkid_next_sibling.as_immutable_table_rowgroup()
.preliminary_collapsed_borders
.block_start
.as_slice())
} else {
NextBlockCollapsedBorders::FromNextRow(
&grandkid_next_sibling.as_immutable_table_row()
.preliminary_collapsed_borders
.block_start
.as_slice())
}
}
None => {
NextBlockCollapsedBorders::FromTable(
CollapsedBorder::block_end(
&*self.block_flow.fragment.style,
CollapsedBorderProvenance::FromTable))
}
}
} else {
NextBlockCollapsedBorders::NotCollapsingBorders
};
TableFlow::update_column_inline_sizes_for_row(
grandkid,
&mut self.column_intrinsic_inline_sizes,
&mut computation,
first_row,
self.table_layout);
if collapsing_borders {
perform_border_collapse_for_row(
grandkid.as_table_row(),
table_inline_collapsed_borders.as_ref().unwrap(),
previous_collapsed_block_end_borders,
next_collapsed_borders_in_block_direction,
&mut self.collapsed_inline_direction_border_widths_for_table,
&mut self.collapsed_block_direction_border_widths_for_table);
previous_collapsed_block_end_borders =
PreviousBlockCollapsedBorders::FromPreviousRow(
grandkid.as_table_row()
.final_collapsed_borders
.block_end
.clone())
}
first_row = false
}
}
} else if kid.is_table_row() {
TableFlow::update_column_inline_sizes_for_row(
kid,
&mut self.column_intrinsic_inline_sizes,
&mut computation,
&mut did_first_row,
self.table_layout)
}
}
let spacing = self.block_flow
.fragment
.style()
.get_inheritedtable()
.border_spacing
.horizontal * (self.column_intrinsic_inline_sizes.len() as i32 + 1);
let spacing = self.spacing().horizontal *
(self.column_intrinsic_inline_sizes.len() as i32 + 1);
computation.surrounding_size = computation.surrounding_size + spacing;
self.block_flow.base.intrinsic_inline_sizes = computation.finish()
@ -295,9 +429,11 @@ impl Flow for TableFlow {
}
let inline_size_computer = InternalTable;
let border_collapse = self.block_flow.fragment.style.get_inheritedtable().border_collapse;
inline_size_computer.compute_used_inline_size(&mut self.block_flow,
layout_context,
containing_block_inline_size);
containing_block_inline_size,
border_collapse);
let inline_start_content_edge = self.block_flow.fragment.border_padding.inline_start;
let inline_end_content_edge = self.block_flow.fragment.border_padding.inline_end;
@ -347,15 +483,41 @@ impl Flow for TableFlow {
self.block_flow.base.flags.remove(IMPACTED_BY_LEFT_FLOATS);
self.block_flow.base.flags.remove(IMPACTED_BY_RIGHT_FLOATS);
let info = ChildInlineSizeInfo {
column_computed_inline_sizes: &self.column_computed_inline_sizes,
spacing: spacing_per_cell,
};
let column_computed_inline_sizes = self.column_computed_inline_sizes.as_slice();
let collapsed_inline_direction_border_widths_for_table =
self.collapsed_inline_direction_border_widths_for_table.as_slice();
let mut collapsed_block_direction_border_widths_for_table =
self.collapsed_block_direction_border_widths_for_table.iter().peekable();
self.block_flow.propagate_assigned_inline_size_to_children(layout_context,
inline_start_content_edge,
inline_end_content_edge,
content_inline_size,
Some(info));
|child_flow,
child_index,
content_inline_size,
writing_mode,
inline_start_margin_edge| {
table_row::propagate_column_inline_sizes_to_child(
child_flow,
child_index,
content_inline_size,
writing_mode,
column_computed_inline_sizes,
&spacing_per_cell,
&None,
inline_start_margin_edge);
if child_flow.is_table_row() {
let child_table_row = child_flow.as_table_row();
child_table_row.populate_collapsed_border_spacing(
collapsed_inline_direction_border_widths_for_table.as_slice(),
&mut collapsed_block_direction_border_widths_for_table);
} else if child_flow.is_table_rowgroup() {
let child_table_rowgroup = child_flow.as_table_rowgroup();
child_table_rowgroup.populate_collapsed_border_spacing(
collapsed_inline_direction_border_widths_for_table.as_slice(),
&mut collapsed_block_direction_border_widths_for_table);
}
})
}
fn assign_block_size<'a>(&mut self, layout_context: &'a LayoutContext<'a>) {
@ -381,7 +543,18 @@ impl Flow for TableFlow {
}
fn build_display_list(&mut self, layout_context: &LayoutContext) {
self.block_flow.build_display_list(layout_context);
let border_painting_mode = match self.block_flow
.fragment
.style
.get_inheritedtable()
.border_collapse {
border_collapse::T::separate => BorderPaintingMode::Separate,
border_collapse::T::collapse => BorderPaintingMode::Hidden,
};
self.block_flow.build_display_list_for_block(box DisplayList::new(),
layout_context,
border_painting_mode);
}
fn repair_style(&mut self, new_style: &Arc<ComputedValues>) {
@ -420,11 +593,13 @@ impl ISizeAndMarginsComputer for InternalTable {
/// CSS Section 10.4: Minimum and Maximum inline-sizes
fn compute_used_inline_size(&self,
block: &mut BlockFlow,
ctx: &LayoutContext,
parent_flow_inline_size: Au) {
layout_context: &LayoutContext,
parent_flow_inline_size: Au,
border_collapse: border_collapse::T) {
let input = self.compute_inline_size_constraint_inputs(block,
parent_flow_inline_size,
ctx);
layout_context,
border_collapse);
let solution = self.solve_inline_size_constraints(block, &input);
self.set_inline_size_constraint_solutions(block, solution);
@ -437,87 +612,6 @@ impl ISizeAndMarginsComputer for InternalTable {
}
}
/// Encapsulates functionality shared among all table-like flows: for now, tables and table
/// rowgroups.
pub trait TableLikeFlow {
/// Lays out the rows of a table.
fn assign_block_size_for_table_like_flow<'a>(&mut self,
layout_context: &'a LayoutContext<'a>,
block_direction_spacing: Au);
}
impl TableLikeFlow for BlockFlow {
fn assign_block_size_for_table_like_flow<'a>(&mut self,
_: &'a LayoutContext<'a>,
block_direction_spacing: Au) {
if self.base.restyle_damage.contains(REFLOW) {
// Our current border-box position.
let block_start_border_padding = self.fragment.border_padding.block_start;
let mut current_block_offset = block_start_border_padding;
// At this point, `current_block_offset` is at the content edge of our box. Now iterate
// over children.
let mut layers_needed_for_descendants = false;
for kid in self.base.child_iter() {
// Mark flows for layerization if necessary to handle painting order correctly.
block::propagate_layer_flag_from_child(&mut layers_needed_for_descendants, kid);
// Account for spacing.
if kid.is_table_row() {
current_block_offset = current_block_offset + block_direction_spacing;
}
// At this point, `current_block_offset` is at the border edge of the child.
flow::mut_base(kid).position.start.b = current_block_offset;
// Move past the child's border box. Do not use the `translate_including_floats`
// function here because the child has already translated floats past its border
// box.
let kid_base = flow::mut_base(kid);
current_block_offset = current_block_offset + kid_base.position.size.block;
}
// Compute any explicitly-specified block size.
// Can't use `for` because we assign to `candidate_block_size_iterator.candidate_value`.
let mut block_size = current_block_offset - block_start_border_padding;
let mut candidate_block_size_iterator = CandidateBSizeIterator::new(
&self.fragment,
self.base.block_container_explicit_block_size);
loop {
match candidate_block_size_iterator.next() {
Some(candidate_block_size) => {
candidate_block_size_iterator.candidate_value =
match candidate_block_size {
MaybeAuto::Auto => block_size,
MaybeAuto::Specified(value) => value
}
}
None => break,
}
}
// Adjust `current_block_offset` as necessary to account for the explicitly-specified
// block-size.
block_size = candidate_block_size_iterator.candidate_value;
let delta = block_size - (current_block_offset - block_start_border_padding);
current_block_offset = current_block_offset + delta;
// Take border, padding, and spacing into account.
let block_end_offset = self.fragment.border_padding.block_end +
block_direction_spacing;
current_block_offset = current_block_offset + block_end_offset;
// Now that `current_block_offset` is at the block-end of the border box, compute the
// final border box position.
self.fragment.border_box.size.block = current_block_offset;
self.fragment.border_box.start.b = Au(0);
self.base.position.size.block = current_block_offset;
}
self.base.restyle_damage.remove(REFLOW_OUT_OF_FLOW | REFLOW);
}
}
/// Information about the intrinsic inline sizes of columns within a table.
///
/// During table inline-size bubbling, we might need to store both a percentage constraint and a
@ -556,7 +650,7 @@ impl ColumnIntrinsicInlineSize {
/// Beware that this is generally only correct for fixed table layout. (Compare CSS 2.1 §
/// 17.5.2.1 with the algorithm in INTRINSIC § 4.)
pub fn minimum(&self, containing_block_inline_size: Au) -> Au {
max(self.minimum_length, containing_block_inline_size.scale_by(self.percentage))
cmp::max(self.minimum_length, containing_block_inline_size.scale_by(self.percentage))
}
/// Returns the higher of the two percentages specified in `self` and `other`.
@ -579,63 +673,206 @@ pub struct ColumnComputedInlineSize {
pub size: Au,
}
/// Inline-size information that we need to push down to table children.
pub struct ChildInlineSizeInfo<'a> {
/// The spacing of the table.
pub spacing: border_spacing::T,
/// The computed inline sizes for each column.
pub column_computed_inline_sizes: &'a [ColumnComputedInlineSize],
pub trait VecExt<T> {
fn push_or_set(&mut self, index: usize, value: T);
fn push_or_mutate(&mut self, index: usize, zero: T) -> &mut T;
}
impl<'a> ChildInlineSizeInfo<'a> {
/// Propagates information computed during inline size assignment to a child of a table, and
/// lays out that child in the inline direction.
pub fn propagate_to_child(&self,
kid: &mut Flow,
child_index: usize,
content_inline_size: Au,
writing_mode: WritingMode,
inline_start_margin_edge: &mut Au) {
// If the child is a table or a row, copy computed inline size information from its parent.
//
// FIXME(pcwalton): This seems inefficient. Reference count it instead?
let inline_size;
if kid.is_table() {
let table_kid = kid.as_table();
table_kid.column_computed_inline_sizes = self.column_computed_inline_sizes.to_vec();
inline_size = content_inline_size
} else if kid.is_table_rowgroup() {
let table_rowgroup_kid = kid.as_table_rowgroup();
table_rowgroup_kid.column_computed_inline_sizes =
self.column_computed_inline_sizes.to_vec();
table_rowgroup_kid.spacing = self.spacing;
inline_size = content_inline_size
} else if kid.is_table_row() {
let table_row_kid = kid.as_table_row();
table_row_kid.column_computed_inline_sizes =
self.column_computed_inline_sizes.to_vec();
table_row_kid.spacing = self.spacing;
inline_size = content_inline_size
} else if kid.is_table_cell() {
// Take spacing into account.
*inline_start_margin_edge = *inline_start_margin_edge + self.spacing.horizontal;
inline_size = self.column_computed_inline_sizes[child_index].size;
impl<T> VecExt<T> for Vec<T> {
fn push_or_set(&mut self, index: usize, value: T) {
if index < self.len() {
self[index] = value
} else {
// ISize of kid flow is our content inline-size.
inline_size = content_inline_size
debug_assert!(index == self.len());
self.push(value)
}
}
{
let kid_base = flow::mut_base(kid);
kid_base.position.start.i = *inline_start_margin_edge;
kid_base.block_container_inline_size = inline_size;
kid_base.block_container_writing_mode = writing_mode
}
// Move over for the next table cell.
if kid.is_table_cell() {
*inline_start_margin_edge = *inline_start_margin_edge + inline_size
fn push_or_mutate(&mut self, index: usize, zero: T) -> &mut T {
if index >= self.len() {
debug_assert!(index == self.len());
self.push(zero)
}
&mut self[index]
}
}
/// Updates the border styles in the block direction for a single row. This function should
/// only be called if border collapsing is on. It is factored out into a separate function
/// because we process children of rowgroups too.
fn perform_border_collapse_for_row(child_table_row: &mut TableRowFlow,
table_inline_borders: &TableInlineCollapsedBorders,
previous_block_borders: PreviousBlockCollapsedBorders,
next_block_borders: NextBlockCollapsedBorders,
inline_spacing: &mut Vec<Au>,
block_spacing: &mut Vec<Au>) {
// Compute interior inline borders.
for (i, this_inline_border) in child_table_row.preliminary_collapsed_borders
.inline
.iter()
.enumerate() {
child_table_row.final_collapsed_borders.inline.push_or_set(i, *this_inline_border);
let inline_spacing = inline_spacing.push_or_mutate(i, Au(0));
*inline_spacing = cmp::max(*inline_spacing, this_inline_border.width)
}
// Collapse edge interior borders with the table.
if let Some(ref mut first_inline_borders) = child_table_row.final_collapsed_borders
.inline
.get_mut(0) {
first_inline_borders.combine(&table_inline_borders.start)
}
if let Some(ref mut last_inline_borders) = child_table_row.final_collapsed_borders
.inline
.last_mut() {
last_inline_borders.combine(&table_inline_borders.end)
}
// Compute block-start borders.
match previous_block_borders {
PreviousBlockCollapsedBorders::FromPreviousRow(previous_block_borders) => {
child_table_row.final_collapsed_borders.block_start = previous_block_borders
}
PreviousBlockCollapsedBorders::FromTable(collapsed_border) => {
child_table_row.final_collapsed_borders.block_start =
iter::repeat(collapsed_border).take(child_table_row.block_flow.base.children.len())
.collect()
}
PreviousBlockCollapsedBorders::NotCollapsingBorders => {}
}
// Compute block-end borders.
let next_block = &mut child_table_row.final_collapsed_borders.block_end;
block_spacing.push(Au(0));
let block_spacing = block_spacing.last_mut().unwrap();
for (i, this_block_border) in child_table_row.preliminary_collapsed_borders
.block_end
.iter()
.enumerate() {
let next_block = next_block.push_or_mutate(i, *this_block_border);
match next_block_borders {
NextBlockCollapsedBorders::FromNextRow(next_block_borders) => {
next_block.combine(&next_block_borders[i]);
}
NextBlockCollapsedBorders::FromTable(ref next_block_borders) => {
next_block.combine(next_block_borders);
}
NextBlockCollapsedBorders::NotCollapsingBorders => {}
}
*block_spacing = cmp::max(*block_spacing, next_block.width)
}
}
/// Encapsulates functionality shared among all table-like flows: for now, tables and table
/// rowgroups.
pub trait TableLikeFlow {
/// Lays out the rows of a table.
fn assign_block_size_for_table_like_flow<'a>(&mut self,
layout_context: &'a LayoutContext<'a>,
block_direction_spacing: Au);
}
impl TableLikeFlow for BlockFlow {
fn assign_block_size_for_table_like_flow<'a>(&mut self,
_: &'a LayoutContext<'a>,
block_direction_spacing: Au) {
debug_assert!(self.fragment.style.get_inheritedtable().border_collapse ==
border_collapse::T::separate || block_direction_spacing == Au(0));
if self.base.restyle_damage.contains(REFLOW) {
// Our current border-box position.
let block_start_border_padding = self.fragment.border_padding.block_start;
let mut current_block_offset = block_start_border_padding;
// At this point, `current_block_offset` is at the content edge of our box. Now iterate
// over children.
let mut layers_needed_for_descendants = false;
for kid in self.base.child_iter() {
// Mark flows for layerization if necessary to handle painting order correctly.
block::propagate_layer_flag_from_child(&mut layers_needed_for_descendants, kid);
// Account for spacing or collapsed borders.
if kid.is_table_row() {
let child_table_row = kid.as_table_row();
current_block_offset = current_block_offset +
match self.fragment.style.get_inheritedtable().border_collapse {
border_collapse::T::separate => block_direction_spacing,
border_collapse::T::collapse => {
child_table_row.collapsed_border_spacing.block_start
}
}
}
// At this point, `current_block_offset` is at the border edge of the child.
flow::mut_base(kid).position.start.b = current_block_offset;
// Move past the child's border box. Do not use the `translate_including_floats`
// function here because the child has already translated floats past its border
// box.
let kid_base = flow::mut_base(kid);
current_block_offset = current_block_offset + kid_base.position.size.block;
}
// Compute any explicitly-specified block size.
// Can't use `for` because we assign to
// `candidate_block_size_iterator.candidate_value`.
let mut block_size = current_block_offset - block_start_border_padding;
let mut candidate_block_size_iterator = CandidateBSizeIterator::new(
&self.fragment,
self.base.block_container_explicit_block_size);
loop {
match candidate_block_size_iterator.next() {
Some(candidate_block_size) => {
candidate_block_size_iterator.candidate_value =
match candidate_block_size {
MaybeAuto::Auto => block_size,
MaybeAuto::Specified(value) => value
}
}
None => break,
}
}
// Adjust `current_block_offset` as necessary to account for the explicitly-specified
// block-size.
block_size = candidate_block_size_iterator.candidate_value;
let delta = block_size - (current_block_offset - block_start_border_padding);
current_block_offset = current_block_offset + delta;
// Take border, padding, and spacing into account.
let block_end_offset = self.fragment.border_padding.block_end +
block_direction_spacing;
current_block_offset = current_block_offset + block_end_offset;
// Now that `current_block_offset` is at the block-end of the border box, compute the
// final border box position.
self.fragment.border_box.size.block = current_block_offset;
self.fragment.border_box.start.b = Au(0);
self.base.position.size.block = current_block_offset;
}
self.base.restyle_damage.remove(REFLOW_OUT_OF_FLOW | REFLOW);
}
}
/// Inline collapsed borders for the table itself.
struct TableInlineCollapsedBorders {
/// The table border at the start of the inline direction.
start: CollapsedBorder,
/// The table border at the end of the inline direction.
end: CollapsedBorder,
}
enum PreviousBlockCollapsedBorders {
FromPreviousRow(Vec<CollapsedBorder>),
FromTable(CollapsedBorder),
NotCollapsingBorders,
}
enum NextBlockCollapsedBorders<'a> {
FromNextRow(&'a [CollapsedBorder]),
FromTable(CollapsedBorder),
NotCollapsingBorders,
}