How To Implement an EditWordBreak Procedure in a RichEdit Control (273139)

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#define WB_CLASS_WHITESPACE 0x00
#define WB_CLASS_LINEBREAK 0x01
#define WB_CLASS_DELIMITER 0x02
#define WB_CLASS_NORMALCHAR 0x03


TCHAR whitespace[]=TEXT(" \t") ;
TCHAR linebreakers[]=TEXT("\r\n") ;
TCHAR delimiters[]=TEXT("[]();:,.\"'") ;

BOOL isInDelimiterList(TCHAR c)
{
  return (_tcschr((LPCTSTR)delimiters,c) != NULL || _tcschr((LPCTSTR)whitespace,c) != NULL || _tcschr((LPCTSTR)linebreakers,c) != NULL) ;
}



int CALLBACK EditWordBreakProcEx(LPTSTR pchText, int ichCurrent, int cch, int code)
{
  int lRet = 0 ;
  int i=0 ;
  BOOL found = FALSE ;
  int initial_pos = ichCurrent ;
  
  switch (code)
  {
  case WB_LEFT:
    {//Finds the beginning of a word to the left of the specified position.
      while(!isInDelimiterList(pchText[ichCurrent]) && ichCurrent>0) ichCurrent-- ;
      if(ichCurrent>0)
         lRet = ichCurrent +1 ;
      else 
         lRet = -1 ;
    }
    break ;
  case WB_RIGHT:
    {
      //Finds the beginning of a word to the right of the specified position. 
      while(!isInDelimiterList(pchText[ichCurrent]) && ichCurrent<cch) ichCurrent ;
      if(ichCurrent>0)
         lRet = ichCurrent -1 ;
      else 
         lRet = -1 ;
    }
    break ;
  case WB_ISDELIMITER:
    {//Checks whether the character at the specified position is a delimiter.
      if(_tcschr((LPCTSTR)delimiters,*pchText) != NULL)
      {
        lRet = TRUE ;
      }
    }
    break ;
  case WB_CLASSIFY:
    { //Retrieves the character class and word break flags of the character at the specified position.  
      if(_tcschr((LPCTSTR)whitespace,*pchText) != NULL)
      {
        lRet = WBF_ISWHITE | WB_CLASS_WHITESPACE ;
      }
      else if(_tcschr((LPCTSTR)delimiters,*pchText) != NULL)
      {
        lRet = WBF_BREAKAFTER | WB_CLASS_DELIMITER ;
      }
      else if(_tcschr((LPCTSTR)linebreakers,*pchText) != NULL)
      {
        lRet = WBF_BREAKLINE | WB_CLASS_DELIMITER ;
      }
      else
      {
        lRet = WB_CLASS_NORMALCHAR ;
      }
    }
    break ;
  case WB_MOVEWORDLEFT:
    // Finds the next character that begins a word before the specified position.
    {
      ichCurrent-- ;
      while(isInDelimiterList(pchText[ichCurrent])) ichCurrent-- ;      
      while(ichCurrent<cch && !found && ichCurrent>=0)
      {
         found = isInDelimiterList(pchText[ichCurrent]) ;
         if(found && ichCurrent>=0)
         {
            lRet = ichCurrent+1 ;
         }
         else
         {
            lRet = -1 ;//This ensures failure unless something is found.                           //Thus, if the supplied string, is exhausted,
                       //we will be called with the next bunch                                    //of characters.
            ichCurrent -- ;
         }
      }
      return lRet ;
    }
    break ;
  case WB_MOVEWORDRIGHT:
    //Finds the next character that begins a word after the specified position. 
    {
      if(!isInDelimiterList(pchText[ichCurrent])) 
         while(!isInDelimiterList(pchText[ichCurrent])&&ichCurrent <cch) ichCurrent++ ;
      while(isInDelimiterList(pchText[ichCurrent]&&ichCurrent <cch)) ichCurrent++ ;
      if(ichCurrent<cch)
         lRet = ichCurrent +1 ;
      else
         lRet = -1 ;
      return lRet ;

    }
    break ;
  case WB_LEFTBREAK:
    //Finds the end-of-word delimiter to the left of the specified position.
    {
      while(!isInDelimiterList(pchText[ichCurrent]) && ichCurrent>0) ichCurrent-- ;
      if(ichCurrent>0)
         lRet = ichCurrent ;
      else 
         lRet = -1 ;
    }
    break ;
  case WB_RIGHTBREAK:
    {//Finds the end-of-word delimiter to the left of the specified position.
      while(!isInDelimiterList(pchText[ichCurrent]) && ichCurrent<cch) ichCurrent ;
      if(ichCurrent>0)
         lRet = ichCurrent ;
      else 
         lRet = -1 ;
    }
    break ;
  }
  return lRet ;
}