| // Copyright 2016 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. |
| |
| #ifndef NGInlineLayoutAlgorithm_h |
| #define NGInlineLayoutAlgorithm_h |
| |
| #include "core/CoreExport.h" |
| #include "core/layout/ng/geometry/ng_logical_offset.h" |
| #include "core/layout/ng/ng_constraint_space_builder.h" |
| #include "core/layout/ng/ng_fragment_builder.h" |
| #include "core/layout/ng/ng_inline_break_token.h" |
| #include "core/layout/ng/ng_layout_algorithm.h" |
| #include "core/layout/ng/ng_line_height_metrics.h" |
| #include "platform/fonts/FontBaseline.h" |
| #include "platform/heap/Handle.h" |
| #include "wtf/Vector.h" |
| |
| namespace blink { |
| |
| class NGConstraintSpace; |
| class NGInlineBreakToken; |
| class NGInlineNode; |
| class NGLayoutInlineItem; |
| class NGLineBoxFragmentBuilder; |
| class NGTextFragmentBuilder; |
| |
| // A class for inline layout (e.g. a <span> with no special style). |
| // |
| // Uses NGLineBreaker to find break opportunities, and let it call back to |
| // construct linebox fragments and its wrapper box fragment. |
| // |
| // From a line breaker, this class manages the current line as a range, |start| |
| // and |end|. |end| can be extended multiple times before creating a line, |
| // usually until |!CanFitOnLine()|. |SetBreakOpportunity| can mark the last |
| // confirmed offset that can fit. |
| class CORE_EXPORT NGInlineLayoutAlgorithm final |
| : public NGLayoutAlgorithm<NGInlineNode, NGInlineBreakToken> { |
| public: |
| NGInlineLayoutAlgorithm(NGInlineNode*, |
| NGConstraintSpace*, |
| NGInlineBreakToken* = nullptr); |
| |
| LayoutUnit MaxInlineSize() const { return max_inline_size_; } |
| |
| // Returns if the current items fit on a line. |
| bool CanFitOnLine() const; |
| |
| // Returns if there were any items. |
| bool HasItems() const; |
| |
| // Set the end offset. |
| void SetEnd(unsigned end_offset); |
| |
| // Set the end offset if caller knows the inline size since the current end. |
| void SetEnd(unsigned index, |
| unsigned end_offset, |
| LayoutUnit inline_size_since_current_end); |
| |
| // Create a line up to the end offset. |
| // Then set the start to the end offset, and thus empty the current line. |
| // @return false if the line does not fit in the constraint space in block |
| // direction. |
| bool CreateLine(); |
| |
| // Returns if a break opportunity was set on the current line. |
| bool HasBreakOpportunity() const; |
| |
| // Returns if there were items after the last break opportunity. |
| bool HasItemsAfterLastBreakOpportunity() const; |
| |
| // Set the break opportunity at the current end offset. |
| void SetBreakOpportunity(); |
| |
| // Create a line up to the last break opportunity. |
| // Items after that are sent to the next line. |
| // @return false if the line does not fit in the constraint space in block |
| // direction. |
| bool CreateLineUpToLastBreakOpportunity(); |
| |
| // Set the start offset of hangables; e.g., spaces or hanging punctuations. |
| // Hangable characters can go beyond the right margin, and are ignored for |
| // center/right alignment. |
| void SetStartOfHangables(unsigned offset); |
| |
| RefPtr<NGLayoutResult> Layout() override; |
| |
| // Compute MinMaxContentSize by performing layout. |
| // Unlike NGLayoutAlgorithm::ComputeMinMaxContentSize(), this function runs |
| // part of layout operations and modifies the state of |this|. |
| MinMaxContentSize ComputeMinMaxContentSizeByLayout(); |
| |
| // Copy fragment data of all lines to LayoutBlockFlow. |
| // TODO(kojii): Move to NGInlineNode (or remove when paint is implemented.) |
| void CopyFragmentDataToLayoutBlockFlow(NGLayoutResult*); |
| |
| // Compute inline size of an NGLayoutInlineItem. |
| // Same as NGLayoutInlineItem::InlineSize(), except that this function can |
| // compute atomic inlines by performing layout. |
| LayoutUnit InlineSize(const NGLayoutInlineItem&); |
| |
| private: |
| bool IsHorizontalWritingMode() const { return is_horizontal_writing_mode_; } |
| |
| // Set the start and the end to the specified offset. |
| // This empties the current line. |
| void Initialize(unsigned index, unsigned offset); |
| |
| LayoutUnit InlineSize(const NGLayoutInlineItem&, |
| unsigned start_offset, |
| unsigned end_offset); |
| LayoutUnit InlineSizeFromLayout(const NGLayoutInlineItem&); |
| const NGLayoutResult* LayoutItem(const NGLayoutInlineItem&); |
| |
| struct LineItemChunk { |
| unsigned index; |
| unsigned start_offset; |
| unsigned end_offset; |
| LayoutUnit inline_size; |
| }; |
| |
| void BidiReorder(Vector<LineItemChunk, 32>*); |
| |
| // Lays out the inline float. |
| // List of actions: |
| // - tries to position the float right away if we have enough space. |
| // - updates the current_opportunity if we actually place the float. |
| // - if it's too wide then we add the float to the unpositioned list so it can |
| // be positioned after we're done with the current line. |
| void LayoutAndPositionFloat(LayoutUnit end_position, LayoutObject*); |
| |
| bool PlaceItems(const Vector<LineItemChunk, 32>&); |
| void AccumulateUsedFonts(const NGLayoutInlineItem&, |
| const LineItemChunk&, |
| NGLineBoxFragmentBuilder*); |
| LayoutUnit PlaceAtomicInline(const NGLayoutInlineItem&, |
| LayoutUnit estimated_baseline, |
| NGLineBoxFragmentBuilder*, |
| NGTextFragmentBuilder*); |
| |
| // Finds the next layout opportunity for the next text fragment. |
| void FindNextLayoutOpportunity(); |
| |
| Vector<RefPtr<NGLayoutResult>, 32> layout_results_; |
| unsigned start_index_ = 0; |
| unsigned start_offset_ = 0; |
| unsigned last_index_ = 0; |
| unsigned end_offset_ = 0; |
| unsigned last_break_opportunity_index_ = 0; |
| unsigned last_break_opportunity_offset_ = 0; |
| LayoutUnit end_position_; |
| LayoutUnit last_break_opportunity_position_; |
| LayoutUnit content_size_; |
| LayoutUnit max_inline_size_; |
| NGFragmentBuilder container_builder_; |
| FontBaseline baseline_type_ = FontBaseline::AlphabeticBaseline; |
| |
| NGLogicalOffset bfc_offset_; |
| NGLogicalRect current_opportunity_; |
| |
| unsigned is_horizontal_writing_mode_ : 1; |
| |
| NGConstraintSpaceBuilder space_builder_; |
| #if DCHECK_IS_ON() |
| unsigned is_bidi_reordered_ : 1; |
| #endif |
| }; |
| |
| } // namespace blink |
| |
| #endif // NGInlineLayoutAlgorithm_h |