[LayoutNG] Introduce NGPhysicalFragment and make NGFragment a 'view'

third_party/WebKit/Source/core/layout/ng/ng_units.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 NGUnits_h
 #define NGUnits_h
 
+#include "core/CoreExport.h"
+#include "core/layout/ng/ng_direction.h"
+#include "core/layout/ng/ng_writing_mode.h"
 #include "platform/LayoutUnit.h"
 
 namespace blink {
 
 class LayoutUnit;
+struct NGPhysicalOffset;
+struct NGPhysicalSize;
 
 struct NGLogicalSize {
   NGLogicalSize() {}
   NGLogicalSize(LayoutUnit inline_size, LayoutUnit block_size)
       : inline_size(inline_size), block_size(block_size) {}
 
   LayoutUnit inline_size;
   LayoutUnit block_size;
+
+  NGPhysicalSize ConvertToPhysical(NGWritingMode mode) const;
 };
 
+// NGLogicalOffset is the position of a rect (typically a fragment) relative to
+// its parent rect in the logical coordinate system.
 struct NGLogicalOffset {
+  NGLogicalOffset() {}
+  NGLogicalOffset(LayoutUnit inline_offset, LayoutUnit block_offset)
+      : inline_offset(inline_offset), block_offset(block_offset) {}
+
   LayoutUnit inline_offset;
   LayoutUnit block_offset;
+
+  // Converts a logical offset to a physical offset. See:
+  // https://drafts.csswg.org/css-writing-modes-3/#logical-to-physical
+  // @param container_size the size of the rect (typically a fragment).
+  // @param inner_size the size of the inner rect (typically a child fragment).
+  CORE_EXPORT NGPhysicalOffset
+  ConvertToPhysical(NGWritingMode mode,
+                    NGDirection direction,
+                    NGPhysicalSize container_size,
+                    NGPhysicalSize inner_size) const;
+};
+
+// NGPhysicalOffset is the position of a rect (typically a fragment) relative to
+// its parent rect in the physical coordinate system.
+struct NGPhysicalOffset {
+  NGPhysicalOffset() {}
+  NGPhysicalOffset(LayoutUnit left, LayoutUnit top) : left(left), top(top) {}
+
+  LayoutUnit left;
+  LayoutUnit top;
 };
 
 struct NGPhysicalSize {
   NGPhysicalSize() {}
   NGPhysicalSize(LayoutUnit width, LayoutUnit height)
       : width(width), height(height) {}
 
   LayoutUnit width;
   LayoutUnit height;
+
+  NGLogicalSize ConvertToLogical(NGWritingMode mode) const;
 };
 
+// NGPhysicalLocation is the position of a rect (typically a fragment) relative
+// to the root document.
 struct NGPhysicalLocation {
+  LayoutUnit left;
   LayoutUnit top;
-  LayoutUnit left;
 };
 
 struct NGPhysicalRect {
   NGPhysicalSize size;
   NGPhysicalLocation location;
 };
 
 struct NGPixelSnappedPhysicalRect {
   int top;
   int left;
   int width;
   int height;
 };
 
 // This struct is used for storing margins, borders or padding of a box on all
 // four edges.
 struct NGBoxStrut {
   LayoutUnit inline_start;
   LayoutUnit inline_end;
   LayoutUnit block_start;
   LayoutUnit block_end;
 
   LayoutUnit InlineSum() const { return inline_start + inline_end; }
   LayoutUnit BlockSum() const { return block_start + block_end; }
 };
 
 }  // namespace blink
 
 #endif  // NGUnits_h