Use Opportunity Iterator to position text fragments in NGLineBuilder

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_layout_opportunity_iterator.h"
 #include "core/layout/ng/ng_physical_fragment.h"
 #include "platform/fonts/FontBaseline.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 class ComputedStyle;
 class FontMetrics;
 class NGConstraintSpace;
 class NGFragmentBuilder;
 class NGInlineNode;
 class NGLayoutInlineItem;
 
 // 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*, const NGConstraintSpace*);
+  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;
 
@@ skipping 37 matching lines @@
 
   // Create fragments for all lines created so far.
   void CreateFragments(NGFragmentBuilder*);
 
   // 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();
 
+  // Finds the next layout opportunity for the next text fragment.
+  void FindNextLayoutOpportunity();
+
  private:
   struct LineItemChunk {
     unsigned index;
     unsigned start_offset;
     unsigned end_offset;
     LayoutUnit inline_size;
   };
 
   void BidiReorder(Vector<LineItemChunk, 32>*);
 
@@ skipping 32 matching lines @@
     // Include |InlineItemMetrics| into the metrics for this line box.
     void UpdateMaxAscentAndDescent(const InlineItemMetrics&);
   };
 
   void PlaceItems(const Vector<LineItemChunk, 32>&);
   void AccumulateUsedFonts(const NGLayoutInlineItem&,
                            const LineItemChunk&,
                            LineBoxData*);
 
   Persistent<NGInlineNode> inline_box_;
-  const NGConstraintSpace* constraint_space_;  // Not owned as STACK_ALLOCATED.
+  NGConstraintSpace* constraint_space_;  // Not owned as STACK_ALLOCATED.
   Vector<RefPtr<NGPhysicalFragment>, 32> fragments_;
   Vector<NGLogicalOffset, 32> offsets_;
   Vector<LineBoxData, 32> line_box_data_list_;
   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_;
 
+  NGLogicalOffset bfc_offset_;
+  NGLogicalRect current_opportunity_;
+
 #if DCHECK_IS_ON()
   unsigned is_bidi_reordered_ : 1;
 #endif
 };
 
 }  // namespace blink
 
 #endif  // NGLineBuilder_h