src/common/imaggif.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/common/imaggif.cpp
   3 // Purpose:     wxGIFHandler
   4 // Author:      Vaclav Slavik & Guillermo Rodriguez Garcia
   5 // RCS-ID:      $Id$
   6 // Copyright:   (c) 1999 Vaclav Slavik & Guillermo Rodriguez Garcia
   7 // Licence:     wxWindows licence
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10 // For compilers that support precompilation, includes "wx.h".
  11 #include "wx/wxprec.h"
  12
  13 #ifdef __BORLANDC__
  14     #pragma hdrstop
  15 #endif
  16
  17 #if wxUSE_IMAGE && wxUSE_GIF
  18
  19 #ifndef WX_PRECOMP
  20     #include "wx/intl.h"
  21     #include "wx/log.h"
  22 #endif
  23
  24 #include "wx/imaggif.h"
  25 #include "wx/gifdecod.h"
  26 #include "wx/wfstream.h"
  27
  28 IMPLEMENT_DYNAMIC_CLASS(wxGIFHandler,wxImageHandler)
  29
  30 //-----------------------------------------------------------------------------
  31 // wxGIFHandler
  32 //-----------------------------------------------------------------------------
  33
  34 #if wxUSE_STREAMS
  35
  36 bool wxGIFHandler::LoadFile(wxImage *image, wxInputStream& stream,
  37                             bool verbose, int index)
  38 {
  39     wxGIFDecoder *decod;
  40     int error;
  41     bool ok = true;
  42
  43 //    image->Destroy();
  44     decod = new wxGIFDecoder(&stream, true);
  45     error = decod->ReadGIF();
  46
  47     if ((error != wxGIF_OK) && (error != wxGIF_TRUNCATED))
  48     {
  49         if (verbose)
  50         {
  51             switch (error)
  52             {
  53                 case wxGIF_INVFORMAT:
  54                     wxLogError(_("GIF: error in GIF image format."));
  55                     break;
  56                 case wxGIF_MEMERR:
  57                     wxLogError(_("GIF: not enough memory."));
  58                     break;
  59                 default:
  60                     wxLogError(_("GIF: unknown error!!!"));
  61                     break;
  62             }
  63         }
  64         delete decod;
  65         return false;
  66     }
  67
  68     if ((error == wxGIF_TRUNCATED) && verbose)
  69     {
  70         wxLogError(_("GIF: data stream seems to be truncated."));
  71         /* go on; image data is OK */
  72     }
  73
  74     if (index != -1)
  75     {
  76         // We're already on index = 0 by default. So no need
  77         // to call GoFrame(0) then. On top of that GoFrame doesn't
  78         // accept an index of 0. (Instead GoFirstFrame() should be used)
  79         // Also if the gif image has only one frame, calling GoFrame(0)
  80         // fails because GoFrame() only works with gif animations.
  81         // (It fails if IsAnimation() returns false)
  82         // All valid reasons to NOT call GoFrame when index equals 0.
  83         if (index != 0)
  84         {
  85             ok = decod->GoFrame(index);
  86         }
  87     }
  88
  89     if (ok)
  90     {
  91         ok = decod->ConvertToImage(image);
  92     }
  93     else
  94     {
  95         wxLogError(_("GIF: Invalid gif index."));
  96     }
  97
  98     delete decod;
  99
 100     return ok;
 101 }
 102
 103 bool wxGIFHandler::SaveFile( wxImage * WXUNUSED(image),
 104                              wxOutputStream& WXUNUSED(stream), bool verbose )
 105 {
 106     if (verbose)
 107         wxLogDebug(wxT("GIF: the handler is read-only!!"));
 108
 109     return false;
 110 }
 111
 112 bool wxGIFHandler::DoCanRead( wxInputStream& stream )
 113 {
 114     wxGIFDecoder decod(&stream);
 115     return decod.CanRead();
 116 }
 117
 118 #endif  // wxUSE_STREAMS
 119
 120 #endif  // wxUSE_GIF