Cleanup IFX_BidiChar

core/include/fxcrt/fx_bidi.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
-#ifndef CORE_SRC_FXCRT_FX_ARABIC_H_
-#define CORE_SRC_FXCRT_FX_ARABIC_H_
+#ifndef CORE_INCLUDE_FXCRT_FX_BIDI_H_
+#define CORE_INCLUDE_FXCRT_FX_BIDI_H_
 
-#include "../../include/fxcrt/fx_arb.h"
+#include "fx_system.h"
 
-class CFX_BidiChar final : public IFX_BidiChar {
+// Processes characters and group them into segments based on text direction.
+class CFX_BidiChar {
  public:
+  enum Direction { NEUTRAL, LEFT, RIGHT };
+
   CFX_BidiChar();
-  ~CFX_BidiChar() override {}
+  ~CFX_BidiChar();
 
-  void SetPolicy(FX_BOOL bSeparateNeutral = TRUE) override;
-  FX_BOOL AppendChar(FX_WCHAR wch) override;
-  FX_BOOL EndChar() override;
-  int32_t GetBidiInfo(int32_t& iStart, int32_t& iCount) override;
-  void Reset() override;
+  // Append a character and classify it as left, right, or neutral.
+  // Returns true if the character has a different direction than the
+  // existing direction to indicate there is a segment to process.
+  bool AppendChar(FX_WCHAR wch);
+
+  // Call this after the last character has been appended. AppendChar()
+  // must not be called after this.
+  // Returns true if there is still a segment to process.
+  bool EndChar();
+
+  // Get information about the segment to process.
+  // The segment's start position and character count is returned in |iStart|
+  // and |iCount|, respectively. Pass in null pointers if the information is
+  // not needed.
+  // Returns the segment direction.
+  Direction GetBidiInfo(int32_t* iStart, int32_t* iCount) const;
 
  private:
-  FX_BOOL m_bSeparateNeutral;
+  void SaveCurrentStateToLastState();
+
+  // Position of the current segment.
   int32_t m_iCurStart;
+
+  // Number of characters in the current segment.
   int32_t m_iCurCount;
-  int32_t m_iCurBidi;
-  int32_t m_iLastBidi;
+
+  // Direction of the current segment.
+  Direction m_CurBidi;
+
+  // Number of characters in the last segment.
   int32_t m_iLastStart;
+
+  // Number of characters in the last segment.
   int32_t m_iLastCount;
+
+  // Direction of the last segment.
+  Direction m_LastBidi;
 };
 
-#endif  // CORE_SRC_FXCRT_FX_ARABIC_H_
+#endif  // CORE_INCLUDE_FXCRT_FX_BIDI_H_