src/common/imaggif.cpp

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