layout: Implement keyword sizes for block layout heuristics (#34695)

Block layout uses some heuristics to guess whether margins are separated
by clearance and then don't collapse. These heuristics now take the
min-content, max-content, fit-content and stretch sizing keywords into
account.

Signed-off-by: Oriol Brufau <obrufau@igalia.com>
This commit is contained in:
Oriol Brufau 2024-12-23 03:00:37 -08:00 committed by GitHub
parent 2ab66ce678
commit 6be0a64939
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GPG key ID: B5690EEEBB952194
9 changed files with 212 additions and 63 deletions

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@ -39,7 +39,7 @@ use crate::layout_box_base::LayoutBoxBase;
use crate::positioned::{AbsolutelyPositionedBox, PositioningContext, PositioningContextLength};
use crate::replaced::ReplacedContents;
use crate::sizing::{self, ComputeInlineContentSizes, ContentSizes, InlineContentSizesResult};
use crate::style_ext::{Clamp, ComputedValuesExt, ContentBoxSizesAndPBM, PaddingBorderMargin};
use crate::style_ext::{ComputedValuesExt, ContentBoxSizesAndPBM, PaddingBorderMargin};
use crate::{
ConstraintSpace, ContainingBlock, ContainingBlockSize, IndefiniteContainingBlock,
SizeConstraint,
@ -102,6 +102,7 @@ impl BlockLevelBox {
fn find_block_margin_collapsing_with_parent(
&self,
layout_context: &LayoutContext,
collected_margin: &mut CollapsedMargin,
containing_block: &ContainingBlock,
) -> bool {
@ -122,9 +123,13 @@ impl BlockLevelBox {
return false;
}
let pbm = style.padding_border_margin(containing_block);
let start_margin = pbm.margin.block_start.auto_is(Au::zero);
collected_margin.adjoin_assign(&CollapsedMargin::new(start_margin));
let ContentBoxSizesAndPBM {
content_box_sizes,
pbm,
..
} = style.content_box_sizes_and_padding_border_margin(&containing_block.into());
let margin = pbm.margin.auto_is(Au::zero);
collected_margin.adjoin_assign(&CollapsedMargin::new(margin.block_start));
let child_boxes = match self {
BlockLevelBox::SameFormattingContextBlock { ref contents, .. } => match contents {
@ -138,35 +143,45 @@ impl BlockLevelBox {
return false;
}
let min_size = style
.content_min_box_size_deprecated(containing_block, &pbm)
.auto_is(Au::zero);
let max_size = style.content_max_box_size_deprecated(containing_block, &pbm);
let prefered_size = style.content_box_size_deprecated(containing_block, &pbm);
let inline_size = prefered_size
.inline
.auto_is(|| {
let margin_inline_start = pbm.margin.inline_start.auto_is(Au::zero);
let margin_inline_end = pbm.margin.inline_end.auto_is(Au::zero);
containing_block.size.inline -
pbm.padding_border_sums.inline -
margin_inline_start -
margin_inline_end
})
.clamp_between_extremums(min_size.inline, max_size.inline);
let block_size = prefered_size
.block
.map(|size| size.clamp_between_extremums(min_size.block, max_size.block));
// FIXME: For BlockLevelBox::Independent, this should take floats into account.
let available_inline_size =
containing_block.size.inline - pbm.padding_border_sums.inline - margin.inline_sum();
let available_block_size = containing_block.size.block.non_auto().map(|block_size| {
Au::zero().max(block_size - pbm.padding_border_sums.block - margin.block_sum())
});
let tentative_block_size = content_box_sizes.block.resolve_extrinsic(
Size::FitContent,
Au::zero(),
available_block_size,
);
let get_inline_content_sizes = || {
let constraint_space = ConstraintSpace::new(
tentative_block_size,
style.writing_mode,
None, /* TODO: support preferred aspect ratios on non-replaced boxes */
);
self.inline_content_sizes(layout_context, &constraint_space)
.sizes
};
let inline_size = content_box_sizes.inline.resolve(
Size::Stretch,
Au::zero(),
available_inline_size,
get_inline_content_sizes,
);
let containing_block_for_children = ContainingBlock {
size: ContainingBlockSize {
inline: inline_size,
block: block_size,
block: tentative_block_size.to_auto_or(),
},
style,
};
if !Self::find_block_margin_collapsing_with_parent_from_slice(
layout_context,
child_boxes,
collected_margin,
&containing_block_for_children,
@ -181,13 +196,13 @@ impl BlockLevelBox {
return false;
}
let end_margin = pbm.margin.block_end.auto_is(Au::zero);
collected_margin.adjoin_assign(&CollapsedMargin::new(end_margin));
collected_margin.adjoin_assign(&CollapsedMargin::new(margin.block_end));
true
}
fn find_block_margin_collapsing_with_parent_from_slice(
layout_context: &LayoutContext,
boxes: &[ArcRefCell<BlockLevelBox>],
margin: &mut CollapsedMargin,
containing_block: &ContainingBlock,
@ -195,7 +210,7 @@ impl BlockLevelBox {
boxes.iter().all(|block_level_box| {
block_level_box
.borrow()
.find_block_margin_collapsing_with_parent(margin, containing_block)
.find_block_margin_collapsing_with_parent(layout_context, margin, containing_block)
})
}
}
@ -230,6 +245,15 @@ impl OutsideMarker {
&self.base.style
}
fn inline_content_sizes(
&self,
layout_context: &LayoutContext,
constraint_space: &ConstraintSpace,
) -> InlineContentSizesResult {
self.base
.inline_content_sizes(layout_context, constraint_space, &self.block_container)
}
fn layout(
&self,
layout_context: &LayoutContext<'_>,
@ -242,11 +266,7 @@ impl OutsideMarker {
&self.marker_style,
None, /* TODO: support preferred aspect ratios on non-replaced boxes */
);
let content_sizes = self.base.inline_content_sizes(
layout_context,
&constraint_space,
&self.block_container,
);
let content_sizes = self.inline_content_sizes(layout_context, &constraint_space);
let containing_block_for_children = ContainingBlock {
size: ContainingBlockSize {
inline: content_sizes.sizes.max_content,
@ -770,6 +790,25 @@ impl BlockLevelBox {
),
}
}
fn inline_content_sizes(
&self,
layout_context: &LayoutContext,
constraint_space: &ConstraintSpace,
) -> InlineContentSizesResult {
let independent_formatting_context = match self {
BlockLevelBox::Independent(independent) => independent,
BlockLevelBox::OutOfFlowAbsolutelyPositionedBox(box_) => &box_.borrow().context,
BlockLevelBox::OutOfFlowFloatBox(float_box) => &float_box.contents,
BlockLevelBox::OutsideMarker(outside_marker) => {
return outside_marker.inline_content_sizes(layout_context, constraint_space)
},
BlockLevelBox::SameFormattingContextBlock { base, contents, .. } => {
return base.inline_content_sizes(layout_context, constraint_space, contents)
},
};
independent_formatting_context.inline_content_sizes(layout_context, constraint_space)
}
}
/// Lay out a normal flow non-replaced block that does not establish a new formatting
@ -844,6 +883,7 @@ fn layout_in_flow_non_replaced_block_level_same_formatting_context(
if !collapsible_with_parent_start_margin && start_margin_can_collapse_with_children {
if let BlockContainer::BlockLevelBoxes(child_boxes) = contents {
BlockLevelBox::find_block_margin_collapsing_with_parent_from_slice(
layout_context,
child_boxes,
&mut block_start_margin,
containing_block,