[LayoutNG] Implement more text-align values and BiDi base direction

third_party/WebKit/Source/core/layout/ng/inline/ng_bidi_paragraph.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 NGBidiParagraph_h
 #define NGBidiParagraph_h
 
+#include "platform/text/TextDirection.h"
 #include "platform/wtf/Allocator.h"
 #include "platform/wtf/Forward.h"
 #include "platform/wtf/Vector.h"
 
 #include <unicode/ubidi.h>
 
 namespace blink {
 
 class ComputedStyle;
 
@@ skipping 10 matching lines @@
  public:
   NGBidiParagraph() {}
   ~NGBidiParagraph();
 
   // Splits the given paragraph to bidi runs and resolves the bidi embedding
   // level of each run.
   // Returns false on failure. Nothing other than the destructor should be
   // called.
   bool SetParagraph(const String&, const ComputedStyle&);
 
-  // Returns whether the paragraph is LTR, RTL, or MIXED.
-  UBiDiDirection Direction() const { return ubidi_getDirection(ubidi_); }
+  // @return the entire text is undirectional and LTR.
+  bool IsAllLtr() const { return ubidi_getDirection(ubidi_) == UBIDI_LTR; }

[eae, 2017/06/20 17:54:41]

Instead of IsAllLtr() could we make this more explicit and have
IsUndirectional() instead?

That way the calling code would read:
if (IsUndirectional() && BaseDirection() == kLtr) 

which is more explicit and less likely to cause call sites to incorrectly use
IsAllLtr() instead of BaseDirection() == kLtr or the other way around.

+
+  // The base direction (a.k.a. paragraph direction) of this block.
+  TextDirection BaseDirection() const { return base_direction_; }
 
   // Returns the end offset of a logical run that starts from the |start|
   // offset.
   unsigned GetLogicalRun(unsigned start, UBiDiLevel*) const;
 
   // Create a list of indices in the visual order.
   // A wrapper for ICU |ubidi_reorderVisual()|.
   static void IndicesInVisualOrder(
       const Vector<UBiDiLevel, 32>& levels,
       Vector<int32_t, 32>* indices_in_visual_order_out);
 
  private:
   UBiDi* ubidi_ = nullptr;
+  TextDirection base_direction_ = TextDirection::kLtr;
 };
 
 }  // namespace blink
 
 #endif  // NGBidiParagraph_h