Re: CRichEditCtrl contents from RTF file

From:
Hector Santos <sant9442@nospam.gmail.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
Tue, 27 Apr 2010 10:26:50 -0400
Message-ID:
<uih5AXh5KHA.620@TK2MSFTNGP02.phx.gbl>
Joe, IMV, this is a MAJOR step back in the programming solid code in
order to support this UNICODE stuff. Wow!! Are you kidding me? Why
is UNICODE such an on-going issue with so many people even after all
these years. Its terrible. Wow!

Personally, in this topic, I think understanding more what the
CRichEditCtrl wants for UNICODE support is whats important here. I
don't see any consistent information about this.

--
HLS

Joseph M. Newcomer wrote:

See below...
On Tue, 27 Apr 2010 01:18:08 -0700, JY <sd@nospamgroup.com> wrote:

Hi,

I have a Wizard based application, in which I have some property pages. In
one of the pages, I have a CRichEditCtrl, and I try to populate its contents
from a RTF file. The porblem is, it works correctly if the RTF file is small
(about 4-5 KB), but when I use a larger file, its contents either don't
display at all, or gets truncated.

The code is shown below. What can I do to show the entire contents of the
RTF file in the control? Also, it should work for all languages - I have
UNICODE defined in the project. m_RECtrl is the rich edit control.

static DWORD CALLBACK MyStreamInCallback(DWORD dwCookie, LPBYTE pbBuff, LONG

****
Why did you declare the cookie as a DWORD and not a DWORD_PTR? This is incorrect,
although in 32-bit Windows it would not have any impact
****

cb, LONG *pcb)
{
  CFile* pFile = (CFile*)(DWORD_PTR)dwCookie;
  *pcb = pFile->Read(pbBuff, cb);

****
Note that the Read should be contained in a try/catch(CFileException * e) structure if you
plan to detect errors correctly
****

  return 0;
}

BOOL CREPage::OnInitDialog()
{
    CBasePage::OnInitDialog();

    if (m_strRTFFilePath.GetLength())
    {
        m_RECtrl.ShowScrollBar(SB_VERT, TRUE);
        CFile eulaFile(m_strRTFFilePath, CFile::modeRead);
****
Note that this constructor must be in a try/catch(CFileException * e) block, since if
there is a problem (such as the file does not exist along the path) then it will throw an
exception
****

         EDITSTREAM es;

        es.dwCookie = (DWORD_PTR)&eulaFile;
        es.pfnCallback = (EDITSTREAMCALLBACK)MyStreamInCallback;
        m_RECtrl.StreamIn(SF_RTF, es);
    }

    return TRUE;
}

int CREPage::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
    if (CBasePage::OnCreate(lpCreateStruct) == -1)
        return -1;

    CRect rect;
    GetClientRect(&rect);
    rect.bottom -= 25;

    m_RECtrl.Create(WS_CHILD | WS_VISIBLE | WS_VSCROLL | ES_MULTILINE, rect,
this, IDC_RICHEDIT_EULA);
    m_RECtrl.SetOptions(ECOOP_OR, ECO_AUTOVSCROLL | ECO_AUTOHSCROLL |
ECO_READONLY);
    m_RECtrl.ModifyStyleEx(0, WS_EX_CLIENTEDGE, SWP_FRAMECHANGED);

    return 0;
}

TIA,
JY

****
Here's the stream callback from my handler:

        class StreamInCookie {
            public:
               CFile * file;
               DWORD_PTR remaining;
               DWORD err;
        };
****
This is retrieving data from a precomputed cache which is in rtf format, and if there is
any timestamp change on an input, it resets all the content and will recompute it from
scratch, ignoring the cache. The cache starts with a binary timestamp and a binary length
value. It also marks the hyperlinks. If you want to see the hyperlink code, I've
attached it
*****
BOOL CIndex::RetrieveFromCache()
    {
     CString filename;
     if(!GetCacheFile(filename))
        return FALSE;
     
     CFile f;
     
     if(!f.Open(filename, CFile::modeRead))
        return FALSE; // open failed

     try { /* try read */
          StreamInCookie streamIn; //
          streamIn.file = &f;

          //****************************************************************
          // [Timestamp]
          //****************************************************************

          TimeStamp ft;
          if(f.Read(&ft, sizeof(TimeStamp)) == 0)
             { /* failed */
              ResetAllContent();
              f.Close();
              return FALSE;
             } /* failed */

          //****************************************************************
          // [eod] End of data position for RTF data
          //****************************************************************

          if(f.Read(&streamIn.remaining, sizeof(DWORD)) == 0)
             { /* failed */
              ResetAllContent();
              f.Close();
              return FALSE;
             } /* failed */

          // Now convert from offset to length
          streamIn.remaining -= f.GetPosition();

          //****************************************************************
          // <...> RTF data
          //****************************************************************
          EDITSTREAM es;
          es.dwCookie = (DWORD_PTR)&streamIn;
          es.pfnCallback = StreamInCallback;
          c_Index.StreamIn(SF_RTF, es);

          if(streamIn.err != ERROR_SUCCESS)
             { /* failed */
              f.Close();
              ResetAllContent();
              return FALSE;
             } /* failed */

          //****************************************************************
          // Read the hyperlink length
          //****************************************************************
          DWORD len;
          if(f.Read(&len, sizeof(DWORD)) == 0)
             { /* failed to get links */
              f.Close();
              ResetAllContent();
              return FALSE;
             } /* failed to get links */

          hyperlinks.SetSize(len);

          //****************************************************************
          // Read the hyperlink data
          //****************************************************************

          for(DWORD i = 0; i < len; i++)
             { /* read each */
              hyperlinks[i] = new Reference;
              if(!hyperlinks[i]->Read(f))
                 { /* failed */
                  if(::GetLastError() == ERROR_HANDLE_EOF)
                     break; // "failure" is EOF (see spec on Reference::Read)
                  f.Close();
                  ResetAllContent();
                  return FALSE;
                 } /* failed */
              MarkLink(c_Index, hyperlinks[i]->range);
             } /* read each */

          //****************************************************************
          // [eod] Read EOD for Fastlink RTF data
          //****************************************************************

          if(f.Read(&streamIn.remaining, sizeof(DWORD)) == 0)
             { /* failed */
              ResetAllContent();
              f.Close();
              return FALSE;
             } /* failed */

          streamIn.remaining -= f.GetPosition(); // convert from offset to length

          //****************************************************************
          // <...> RTF data
          //****************************************************************
          c_FastIndex.StreamIn(SF_RTF, es);

          if(streamIn.err != ERROR_SUCCESS)
             { /* failed */
              ResetAllContent();
              f.Close();
              return FALSE;
             } /* failed */

          //****************************************************************
          // Read the hyperlink length
          //****************************************************************

          if(f.Read(&len, sizeof(DWORD)) == 0)
             { /* failed to get links */
              ResetAllContent();
              f.Close();
              return FALSE;
             } /* failed to get links */

          fastlinks.SetSize(len);

          //****************************************************************
          // Read the hyperlink data
          //****************************************************************

          for(i = 0; i < len; i++)
             { /* read each */
              if(!fastlinks[i].Read(f))
                 { /* failed */
                  if(::GetLastError() == ERROR_HANDLE_EOF)
                     break;
                  f.Close();
                  ResetAllContent();
                  return FALSE;
                 } /* failed */
              MarkLink(c_FastIndex, fastlinks[i].range);
             } /* read each */
          //****************************************************************
         } /* try read */
     catch(CFileException * e)
        { /* read error */
         e->Delete();
         ResetAllContent();
         f.Close();
         return FALSE;
        } /* read error */
     f.Close();
     c_Index.SetSel(0,0);
     c_FastIndex.SetSel(0,0);
     return TRUE;
    } // CIndex::RetrieveFromCache

void CIndex::MarkLink(CRichEditCtrlEx & ctl, CHARRANGE & range)
    {
     CHARFORMAT2 linkfmt;

     ctl.SetSel(range);

     linkfmt.cbSize = sizeof(CHARFORMAT2);
     linkfmt.dwMask = CFM_LINK;
     linkfmt.dwEffects = CFE_LINK;
     linkfmt.dwMask = CFM_LINK;
     ctl.SetSelectionCharFormat(linkfmt);
    } // CIndex::MarkLink

/* static */ DWORD CALLBACK CIndex::StreamInCallback(DWORD_PTR cookie, LPBYTE buffer, LONG
count, LONG * pcb)
    {
     StreamInCookie * streamIn = (StreamInCookie *)cookie;
     if(streamIn->remaining == 0)
        { /* all done */
         *pcb = 0;
         streamIn->err = ERROR_SUCCESS;
         return 1; // nonzero value terminates read
        } /* all done */

     DWORD bytesToRead = min(streamIn->remaining, (DWORD)count);

     UINT bytesRead;
     try {
          bytesRead = streamIn->file->Read(buffer, bytesToRead);
         }
     catch(CFileException * e)
         { /* catch */
          streamIn->err = e->m_lOsError;
          e->Delete();
          streamIn->remaining = 0;
          return 1;
         } /* catch */

     if(bytesRead == 0)
        { /* read error */
         streamIn->err = ::GetLastError();
         *pcb = 0;
         return 1; // return nonzero to stop operation
        } /* read error */

     streamIn->remaining -= bytesRead;
     *pcb = bytesRead;
     streamIn->err = ERROR_SUCCESS;
     return 0;
    } // CIndex::StreamInCallback
Joseph M. Newcomer [MVP]
email: newcomer@flounder.com
Web: http://www.flounder.com
MVP Tips: http://www.flounder.com/mvp_tips.htm


--
HLS

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