CRichEditCtrl::LineLength returns strange result

Marty Wagner -- marty@concentra.com
Wednesday, March 27, 1996

     Platform:
     NT 3.1, 48 megs RAM, VC++ 4.0
      
      I tried to use CRichEditCtrl::LineLength to get the length of a line 
      and found that it didn't return what I thought it would return. 
     Often, it 
      would return a number that was clearly less than the actual number of 
      characters in the line.  I know that LineLength is supposed to ignore 
     selected characters, but in this case, there are no characters that 
     are selected. 
     
      I have a simple test to show this. It requires adding an OnChar
     handler for  CWordPadView in the WordPad sample application. Whever 
     the user enters 
      a carriage return, it looks at the previous line and calls LineLength 
     on that line.
      Then it calls GetLine and prints out the line that it gets, along 
     with the length
      of the line according to GetLine. 
     
     
      If I run WordPad and type the following (where  means carriage 
     return. Note the inclusionn
      of spaces!):
      1 2  3
     
      I get the following printed out. Note that the actual size is correct 
     (takes carriage return/line
      feedd into account). However, the length as reported by LineLength is
     alway 1 even though I keep
      adding spaces)
     
     wordpad: The length of line 0 is 1 chars 
     wordpad: The string found was "1
     "
     Its actual size is 3
     wordpad: The length of line 1 is 1 chars 
     wordpad: The string found was " 2
     "
     Its actual size is 4
     wordpad: The length of line 2 is 1 chars 
     wordpad: The string found was "  3
     "
     Its actual size is 5
     
     
     
     void CWordPadView::OnChar(UINT nChar, UINT nRepCnt, UINT nFlags) 
     {
     
             CRichEditView::OnChar(nChar, nRepCnt, nFlags);
     
             if (VK_RETURN == nChar)
             {
                     long nCurLine = GetRichEditCtrl().LineFromChar (-1); 
                     if (0 == nCurLine) 
                             return;
     
                     long nPrevLine = nCurLine - 1;
     
                     int nLineLength = GetRichEditCtrl().LineLength 
     (nPrevLine);
     
                     TRACE ("The length of line %d is %d chars\n", 
     nPrevLine, nLineLength);
     
                     char*   ptsLine = new char [128];
     
                     int nActualLine = GetRichEditCtrl().GetLine 
     (nPrevLine, ptsLine, 128);
     
                     CString sStr (ptsLine, nActualLine);
     
                     TRACE ("The string found was \"%s\"\n", sStr);
     
     
     
     
             }
     }
     
     
     
     Marty Wagner
     Concentra Corporation
     marty@concentra.com

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Oleg Moroz -- moroz@inist.ru
Saturday, March 30, 1996

Note that an argument to LineLength method (both in CRichEditCtrl and
CEdit) is not a line index (although some clever man at MS called it
nLine), it's _character_ index... I've stumbled upon this too...

Oleg

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