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// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "third_party/blink/renderer/core/layout/ng/list/ng_unpositioned_list_marker.h"
#include "third_party/blink/renderer/core/layout/layout_list_marker.h"
#include "third_party/blink/renderer/core/layout/ng/inline/ng_fragment_items_builder.h"
#include "third_party/blink/renderer/core/layout/ng/inline/ng_physical_line_box_fragment.h"
#include "third_party/blink/renderer/core/layout/ng/list/layout_ng_outside_list_marker.h"
#include "third_party/blink/renderer/core/layout/ng/ng_box_fragment.h"
#include "third_party/blink/renderer/core/layout/ng/ng_box_fragment_builder.h"
#include "third_party/blink/renderer/core/layout/ng/ng_constraint_space.h"
#include "third_party/blink/renderer/core/layout/ng/ng_layout_result.h"
namespace blink {
NGUnpositionedListMarker::NGUnpositionedListMarker(
LayoutNGOutsideListMarker* marker)
: marker_layout_object_(marker) {}
NGUnpositionedListMarker::NGUnpositionedListMarker(const NGBlockNode& node)
: NGUnpositionedListMarker(
ToLayoutNGOutsideListMarker(node.GetLayoutBox())) {}
// Returns true if this is an image marker.
bool NGUnpositionedListMarker::IsImage() const {
DCHECK(marker_layout_object_);
return marker_layout_object_->Marker().IsMarkerImage(*marker_layout_object_);
}
// Compute the inline offset of the marker, relative to the list item.
// The marker is relative to the border box of the list item and has nothing
// to do with the content offset.
// Open issue at https://github.com/w3c/csswg-drafts/issues/2361
LayoutUnit NGUnpositionedListMarker::InlineOffset(
const LayoutUnit marker_inline_size) const {
DCHECK(marker_layout_object_);
auto margins = LayoutListMarker::InlineMarginsForOutside(
marker_layout_object_->StyleRef(), IsImage(), marker_inline_size);
return margins.first;
}
scoped_refptr<const NGLayoutResult> NGUnpositionedListMarker::Layout(
const NGConstraintSpace& parent_space,
const ComputedStyle& parent_style,
FontBaseline baseline_type) const {
DCHECK(marker_layout_object_);
NGBlockNode marker_node(marker_layout_object_);
// We need the first-line baseline from the list-marker, instead of the
// typical atomic-inline baseline.
scoped_refptr<const NGLayoutResult> marker_layout_result =
marker_node.LayoutAtomicInline(parent_space, parent_style,
parent_space.UseFirstLineStyle(),
NGBaselineAlgorithmType::kFirstLine);
DCHECK(marker_layout_result);
return marker_layout_result;
}
base::Optional<LayoutUnit> NGUnpositionedListMarker::ContentAlignmentBaseline(
const NGConstraintSpace& space,
FontBaseline baseline_type,
const NGPhysicalFragment& content) const {
// Compute the baseline of the child content.
if (content.IsLineBox()) {
const auto& line_box = To<NGPhysicalLineBoxFragment>(content);
// If this child is an empty line-box, the list marker should be aligned
// with the next non-empty line box produced. (This can occur with floats
// producing empty line-boxes).
if (line_box.IsEmptyLineBox() && !line_box.BreakToken()->IsFinished())
return base::nullopt;
return line_box.Metrics().ascent;
}
// If this child content does not have any line boxes, the list marker
// should be aligned to the first line box of next child.
// https://github.com/w3c/csswg-drafts/issues/2417
return NGBoxFragment(space.GetWritingMode(), space.Direction(),
To<NGPhysicalBoxFragment>(content))
.FirstBaseline();
}
void NGUnpositionedListMarker::AddToBox(
const NGConstraintSpace& space,
FontBaseline baseline_type,
const NGPhysicalFragment& content,
const NGBoxStrut& border_scrollbar_padding,
const NGLayoutResult& marker_layout_result,
LayoutUnit content_baseline,
LogicalOffset* content_offset,
NGBoxFragmentBuilder* container_builder) const {
const NGPhysicalBoxFragment& marker_physical_fragment =
To<NGPhysicalBoxFragment>(marker_layout_result.PhysicalFragment());
// Compute the inline offset of the marker.
NGBoxFragment marker_fragment(space.GetWritingMode(), space.Direction(),
marker_physical_fragment);
LogicalOffset marker_offset(InlineOffset(marker_fragment.Size().inline_size),
content_offset->block_offset);
// Adjust the block offset to align baselines of the marker and the content.
NGLineHeightMetrics marker_metrics = marker_fragment.BaselineMetrics(
/* margins */ NGLineBoxStrut(), baseline_type);
LayoutUnit baseline_adjust = content_baseline - marker_metrics.ascent;
if (baseline_adjust >= 0) {
marker_offset.block_offset += baseline_adjust;
} else {
// If the ascent of the marker is taller than the ascent of the content,
// push the content down.
content_offset->block_offset -= baseline_adjust;
}
marker_offset.inline_offset += ComputeIntrudedFloatOffset(
space, container_builder, border_scrollbar_padding,
marker_offset.block_offset);
DCHECK(container_builder);
if (NGFragmentItemsBuilder* items_builder =
container_builder->ItemsBuilder()) {
items_builder->AddListMarker(marker_physical_fragment, marker_offset);
return;
}
container_builder->AddChild(marker_physical_fragment, marker_offset);
}
LayoutUnit NGUnpositionedListMarker::AddToBoxWithoutLineBoxes(
const NGConstraintSpace& space,
FontBaseline baseline_type,
const NGLayoutResult& marker_layout_result,
NGBoxFragmentBuilder* container_builder) const {
const NGPhysicalBoxFragment& marker_physical_fragment =
To<NGPhysicalBoxFragment>(marker_layout_result.PhysicalFragment());
// When there are no line boxes, marker is top-aligned to the list item.
// https://github.com/w3c/csswg-drafts/issues/2417
LogicalSize marker_size =
marker_physical_fragment.Size().ConvertToLogical(space.GetWritingMode());
LogicalOffset offset(InlineOffset(marker_size.inline_size), LayoutUnit());
DCHECK(container_builder);
DCHECK(!container_builder->ItemsBuilder());
container_builder->AddChild(marker_physical_fragment, offset);
return marker_size.block_size;
}
// Find the opportunity for marker, and compare it to ListItem, then compute the
// diff as intruded offset.
LayoutUnit NGUnpositionedListMarker::ComputeIntrudedFloatOffset(
const NGConstraintSpace& space,
const NGBoxFragmentBuilder* container_builder,
const NGBoxStrut& border_scrollbar_padding,
LayoutUnit marker_block_offset) const {
DCHECK(container_builder);
// If the BFC block-offset isn't resolved, the intruded offset isn't
// available either.
if (!container_builder->BfcBlockOffset())
return LayoutUnit();
// Because opportunity.rect is in the content area of LI, so origin_offset
// should plus border_scrollbar_padding.inline_start, and available_size
// should minus border_scrollbar_padding.
NGBfcOffset origin_offset = {
container_builder->BfcLineOffset() +
border_scrollbar_padding.inline_start,
*container_builder->BfcBlockOffset() + marker_block_offset};
LayoutUnit available_size = container_builder->InlineSize() -
border_scrollbar_padding.inline_start -
border_scrollbar_padding.inline_end;
NGLayoutOpportunity opportunity =
space.ExclusionSpace().FindLayoutOpportunity(origin_offset,
available_size);
DCHECK(marker_layout_object_);
const TextDirection direction = marker_layout_object_->StyleRef().Direction();
if (direction == TextDirection::kLtr) {
// If Ltr, compare the left side.
if (opportunity.rect.LineStartOffset() > origin_offset.line_offset)
return opportunity.rect.LineStartOffset() - origin_offset.line_offset;
} else if (opportunity.rect.LineEndOffset() <
origin_offset.line_offset + available_size) {
// If Rtl, Compare the right side.
return origin_offset.line_offset + available_size -
opportunity.rect.LineEndOffset();
}
return LayoutUnit();
}
#if DCHECK_IS_ON()
// TODO: Currently we haven't supported ::marker, so the margin-top of marker
// should always be zero. And this make us could resolve LI's BFC block-offset
// in NGBlockLayoutAlgorithm::PositionOrPropagateListMarker and
// NGBlockLayoutAlgorithm::PositionListMarkerWithoutLineBoxes without consider
// marker's margin-top.
void NGUnpositionedListMarker::CheckMargin() const {
DCHECK(marker_layout_object_);
DCHECK(marker_layout_object_->StyleRef().MarginBefore().IsZero());
}
#endif
} // namespace blink
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