[LayoutNG] Construct ConstraintSpace form Physical

third_party/WebKit/Source/core/layout/ng/ng_constraint_space.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 NGConstraintSpace_h
 #define NGConstraintSpace_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/ng_physical_constraint_space.h"
 #include "core/layout/ng/ng_writing_mode.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class LayoutBox;
 class NGDerivedConstraintSpace;
 class NGFragment;
 class NGLayoutOpportunityIterator;
 
 // The NGConstraintSpace represents a set of constraints and available space
 // which a layout algorithm may produce a NGFragment within. It is a view on
 // top of a NGPhysicalConstraintSpace and provides accessor methods in the
 // logical coordinate system defined by the writing mode given.
 class CORE_EXPORT NGConstraintSpace
     : public GarbageCollected<NGConstraintSpace> {
  public:
   // Constructs a constraint space with a new backing NGPhysicalConstraintSpace.
   NGConstraintSpace(NGWritingMode writing_mode, NGLogicalSize container_size);
 
+  // Constructs a constraint space based on an existing backing
+  // NGPhysicalConstraintSpace.
+  NGConstraintSpace(NGWritingMode writing_mode, NGPhysicalConstraintSpace*);
+
   // Constructs a constraint space with a different NGWritingMode.
   NGConstraintSpace(NGWritingMode writing_mode,
                     const NGConstraintSpace* constraint_space)
-      : physical_space_(constraint_space->physical_space_),
+      : physical_space_(constraint_space->PhysicalSpace()),
         writing_mode_(writing_mode) {}
 
+  // TODO: This should either be removed or also take an offset (if we merge
+  // this with NGDerivedConstraintSpace).
   NGConstraintSpace(const NGConstraintSpace& other,
                     NGLogicalSize container_size);
 
+  NGPhysicalConstraintSpace* PhysicalSpace() const { return physical_space_; }

[cbiesinger, 2016/08/29 16:37:42]

Personally I'd name this PhysicalConstraintSpace because on first reading I
expected this to return a size indicating the available space, but up to you

+  NGWritingMode WritingMode() const {
+    return static_cast<NGWritingMode>(writing_mode_);
+  }
+
   // Size of the container. Used for the following three cases:
   // 1) Percentage resolution.
   // 2) Resolving absolute positions of children.
   // 3) Defining the threashold that triggers the presence of a scrollbar. Only
   //    applies if the corresponding scrollbarTrigger flag has been set for the
   //    direction.
   NGLogicalSize ContainerSize() const;
 
   // Returns the effective size of the constraint space. Defaults to
   // ContainerSize() for the root constraint space but derived constraint spaces
@@ skipping 56 matching lines @@
 
  private:
   Persistent<NGConstraintSpace> constraint_space_;
   unsigned clear_;
   bool for_inline_or_bfc_;
 };
 
 }  // namespace blink
 
 #endif  // NGConstraintSpace_h