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      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 #include "core/include/fxcrt/fx_bidi.h"
      8 #include "core/include/fxcrt/fx_ucd.h"
      9 
     10 CFX_BidiChar::CFX_BidiChar()
     11     : m_iCurStart(0),
     12       m_iCurCount(0),
     13       m_CurBidi(NEUTRAL),
     14       m_iLastStart(0),
     15       m_iLastCount(0),
     16       m_LastBidi(NEUTRAL) {
     17 }
     18 
     19 CFX_BidiChar::~CFX_BidiChar() {
     20 }
     21 
     22 bool CFX_BidiChar::AppendChar(FX_WCHAR wch) {
     23   FX_DWORD dwProps = FX_GetUnicodeProperties(wch);
     24   int32_t iBidiCls = (dwProps & FX_BIDICLASSBITSMASK) >> FX_BIDICLASSBITS;
     25   Direction bidi = NEUTRAL;
     26   switch (iBidiCls) {
     27     case FX_BIDICLASS_L:
     28     case FX_BIDICLASS_AN:
     29     case FX_BIDICLASS_EN:
     30       bidi = LEFT;
     31       break;
     32     case FX_BIDICLASS_R:
     33     case FX_BIDICLASS_AL:
     34       bidi = RIGHT;
     35       break;
     36   }
     37 
     38   bool bRet = (bidi != m_CurBidi);
     39   if (bRet) {
     40     SaveCurrentStateToLastState();
     41     m_CurBidi = bidi;
     42   }
     43   m_iCurCount++;
     44   return bRet;
     45 }
     46 
     47 bool CFX_BidiChar::EndChar() {
     48   SaveCurrentStateToLastState();
     49   return m_iLastCount > 0;
     50 }
     51 
     52 CFX_BidiChar::Direction CFX_BidiChar::GetBidiInfo(int32_t* iStart,
     53                                                   int32_t* iCount) const {
     54   if (iStart)
     55     *iStart = m_iLastStart;
     56   if (iCount)
     57     *iCount = m_iLastCount;
     58   return m_LastBidi;
     59 }
     60 
     61 void CFX_BidiChar::SaveCurrentStateToLastState() {
     62   m_LastBidi = m_CurBidi;
     63   m_iLastStart = m_iCurStart;
     64   m_iCurStart = m_iCurCount;
     65   m_iLastCount = m_iCurCount - m_iLastStart;
     66 }
     67