[LayoutNG] Add NGInlineBreakToken and back of NGInlineLayoutAlgorithm

third_party/WebKit/Source/core/layout/ng/ng_line_builder.h

-// 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 NGLineBuilder_h
-#define NGLineBuilder_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_line_height_metrics.h"
-#include "platform/fonts/FontBaseline.h"
-#include "platform/heap/Handle.h"
-#include "wtf/Vector.h"
-
-namespace blink {
-
-class NGConstraintSpace;
-class NGInlineNode;
-class NGLayoutInlineItem;
-class NGLineBoxFragmentBuilder;
-class NGTextFragmentBuilder;
-
-// NGLineBuilder creates the fragment tree for a line.
-// NGLineBuilder 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 NGLineBuilder final {
-  STACK_ALLOCATED();
-
- public:
-  NGLineBuilder(NGInlineNode*, NGConstraintSpace*);
-
-  const NGConstraintSpace& ConstraintSpace() const {
-    return *constraint_space_;
-  }
-
-  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 start offset.
-  // Set the end as well, and therefore empties the current line.
-  void SetStart(unsigned index, unsigned offset);
-
-  // 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.
-  void 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.
-  void 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);
-
-  // Create fragments for all lines created so far.
-  RefPtr<NGLayoutResult> CreateFragments();
-
-  // Copy fragment data of all lines created by this NGLineBuilder to
-  // LayoutBlockFlow.
-  // This must run after |CreateFragments()|, and after the fragments it created
-  // are placed.
-  void CopyFragmentDataToLayoutBlockFlow();
-
-  // 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_; }
-
-  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*);
-
-  void 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();
-
-  Persistent<NGInlineNode> inline_box_;
-  NGConstraintSpace* constraint_space_;  // Not owned as STACK_ALLOCATED.
-  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_;
-  RefPtr<NGLayoutResult> container_layout_result_;
-  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  // NGLineBuilder_h