1 // Copyright 2014 PDFium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com 6 7 #ifndef CORE_INCLUDE_FXCRT_FX_BIDI_H_ 8 #define CORE_INCLUDE_FXCRT_FX_BIDI_H_ 9 10 #include "fx_system.h" 11 12 // Processes characters and group them into segments based on text direction. 13 class CFX_BidiChar { 14 public: 15 enum Direction { NEUTRAL, LEFT, RIGHT }; 16 17 CFX_BidiChar(); 18 ~CFX_BidiChar(); 19 20 // Append a character and classify it as left, right, or neutral. 21 // Returns true if the character has a different direction than the 22 // existing direction to indicate there is a segment to process. 23 bool AppendChar(FX_WCHAR wch); 24 25 // Call this after the last character has been appended. AppendChar() 26 // must not be called after this. 27 // Returns true if there is still a segment to process. 28 bool EndChar(); 29 30 // Get information about the segment to process. 31 // The segment's start position and character count is returned in |iStart| 32 // and |iCount|, respectively. Pass in null pointers if the information is 33 // not needed. 34 // Returns the segment direction. 35 Direction GetBidiInfo(int32_t* iStart, int32_t* iCount) const; 36 37 private: 38 void SaveCurrentStateToLastState(); 39 40 // Position of the current segment. 41 int32_t m_iCurStart; 42 43 // Number of characters in the current segment. 44 int32_t m_iCurCount; 45 46 // Direction of the current segment. 47 Direction m_CurBidi; 48 49 // Number of characters in the last segment. 50 int32_t m_iLastStart; 51 52 // Number of characters in the last segment. 53 int32_t m_iLastCount; 54 55 // Direction of the last segment. 56 Direction m_LastBidi; 57 }; 58 59 #endif // CORE_INCLUDE_FXCRT_FX_BIDI_H_ 60
