[LayoutNG] Refactor NGLineBreaker for ShapingLineBreaker

third_party/WebKit/Source/core/layout/ng/inline/ng_inline_layout_algorithm.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 NGInlineLayoutAlgorithm_h
 #define NGInlineLayoutAlgorithm_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/geometry/ng_logical_offset.h"
 #include "core/layout/ng/inline/ng_inline_box_state.h"
 #include "core/layout/ng/inline/ng_inline_break_token.h"
+#include "core/layout/ng/inline/ng_inline_item_result.h"
 #include "core/layout/ng/inline/ng_line_height_metrics.h"
 #include "core/layout/ng/ng_constraint_space_builder.h"
 #include "core/layout/ng/ng_fragment_builder.h"
 #include "core/layout/ng/ng_layout_algorithm.h"
 #include "platform/fonts/FontBaseline.h"
 #include "platform/heap/Handle.h"
 #include "platform/wtf/Vector.h"
 
 namespace blink {
 
 class NGConstraintSpace;
 class NGInlineBreakToken;
 class NGInlineNode;
 class NGInlineItem;
 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.
+// This class determines the position of NGInlineItem and build line boxes.
 //
-// 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.
+// Uses NGLineBreaker to find NGInlineItems to form a line.
 class CORE_EXPORT NGInlineLayoutAlgorithm final
     : public NGLayoutAlgorithm<NGInlineNode, NGInlineBreakToken> {
  public:
   NGInlineLayoutAlgorithm(NGInlineNode*,
                           NGConstraintSpace*,
                           NGInlineBreakToken* = nullptr);
 
-  LayoutUnit MaxInlineSize() const { return max_inline_size_; }
+  // The available width for the current line.
+  LayoutUnit AvailableWidth() const;
 
-  // 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.
+  // Create a 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);
+  bool CreateLine(NGInlineItemResults*, RefPtr<NGInlineBreakToken> = nullptr);
 
   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();
-
-  // Compute inline size of an NGInlineItem.
-  // Same as NGInlineItem::InlineSize(), except that this function can compute
-  // atomic inlines by performing layout.
-  LayoutUnit InlineSize(const NGInlineItem&);
+  // 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*);
 
  private:
   bool IsHorizontalWritingMode() const { return is_horizontal_writing_mode_; }
 
   bool IsFirstLine() const;
   const ComputedStyle& FirstLineStyle() const;
   const ComputedStyle& LineStyle() const;
 
-  // Set the start and the end to the specified offset.
-  // This empties the current line.
-  void Initialize(unsigned index, unsigned offset);
+  void BidiReorder(NGInlineItemResults*);
 
-  LayoutUnit InlineSize(const NGInlineItem&,
-                        unsigned start_offset,
-                        unsigned end_offset);
-  LayoutUnit InlineSizeFromLayout(const NGInlineItem&);
-  const NGLayoutResult* LayoutItem(const NGInlineItem&);
-
-  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 NGInlineItem&,
-                           const LineItemChunk&,
-                           NGLineBoxFragmentBuilder*);
+  bool PlaceItems(NGInlineItemResults*, RefPtr<NGInlineBreakToken>);
   LayoutUnit PlaceAtomicInline(const NGInlineItem&,
+                               NGInlineItemResult*,
                                NGLineBoxFragmentBuilder*,
                                NGInlineBoxState*,
                                NGTextFragmentBuilder*);
 
   // Finds the next layout opportunity for the next text fragment.
   void FindNextLayoutOpportunity();
 
-  Vector<RefPtr<NGLayoutResult>, 32> layout_results_;
   NGInlineLayoutStateStack box_states_;
-  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_;
   FontBaseline baseline_type_ = FontBaseline::kAlphabeticBaseline;
 
   NGLogicalOffset bfc_offset_;
   NGLogicalRect current_opportunity_;
 
   unsigned is_horizontal_writing_mode_ : 1;
   unsigned disallow_first_line_rules_ : 1;
 
   NGConstraintSpaceBuilder space_builder_;
-#if DCHECK_IS_ON()
-  unsigned is_bidi_reordered_ : 1;
-#endif
 };
 
 }  // namespace blink
 
 #endif  // NGInlineLayoutAlgorithm_h