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 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  11 #pragma implementation "imaggif.h"
  12 #endif
  13
  14 // For compilers that support precompilation, includes "wx.h".
  15 #include "wx/wxprec.h"
  16
  17 #ifdef __BORLANDC__
  18 #  pragma hdrstop
  19 #endif
  20
  21 #ifndef WX_PRECOMP
  22 #  include "wx/defs.h"
  23 #endif
  24
  25 #if wxUSE_IMAGE && wxUSE_GIF
  26
  27 #include "wx/imaggif.h"
  28 #include "wx/gifdecod.h"
  29 #include "wx/wfstream.h"
  30 #include "wx/log.h"
  31 #include "wx/intl.h"
  32
  33 IMPLEMENT_DYNAMIC_CLASS(wxGIFHandler,wxImageHandler)
  34
  35 //-----------------------------------------------------------------------------
  36 // wxGIFHandler
  37 //-----------------------------------------------------------------------------
  38
  39 #if wxUSE_STREAMS
  40
  41 bool wxGIFHandler::LoadFile(wxImage *image, wxInputStream& stream,
  42                             bool verbose, int index)
  43 {
  44     wxGIFDecoder *decod;
  45     int error;
  46     bool ok = true;
  47
  48 //    image->Destroy();
  49     decod = new wxGIFDecoder(&stream, true);
  50     error = decod->ReadGIF();
  51
  52     if ((error != wxGIF_OK) && (error != wxGIF_TRUNCATED))
  53     {
  54         if (verbose)
  55         {
  56             switch (error)
  57             {
  58                 case wxGIF_INVFORMAT:
  59                     wxLogError(_("GIF: error in GIF image format."));
  60                     break;
  61                 case wxGIF_MEMERR:
  62                     wxLogError(_("GIF: not enough memory."));
  63                     break;
  64                 default:
  65                     wxLogError(_("GIF: unknown error!!!"));
  66                     break;
  67             }
  68         }
  69         delete decod;
  70         return false;
  71     }
  72
  73     if ((error == wxGIF_TRUNCATED) && verbose)
  74     {
  75         wxLogError(_("GIF: data stream seems to be truncated."));
  76         /* go on; image data is OK */
  77     }
  78
  79     if (index != -1)
  80     {
  81         // We're already on index = 0 by default. So no need
  82         // to call GoFrame(0) then. On top of that GoFrame doesn't
  83         // accept an index of 0. (Instead GoFirstFrame() should be used)
  84         // Also if the gif image has only one frame, calling GoFrame(0)
  85         // fails because GoFrame() only works with gif animations.
  86         // (It fails if IsAnimation() returns false)
  87         // All valid reasons to NOT call GoFrame when index equals 0.
  88         if (index != 0)
  89         {
  90             ok = decod->GoFrame(index);
  91         }
  92     }
  93
  94     if (ok)
  95     {
  96         ok = decod->ConvertToImage(image);
  97     }
  98     else
  99     {
 100         wxLogError(_("GIF: Invalid gif index."));
 101     }
 102
 103     delete decod;
 104
 105     return ok;
 106 }
 107
 108 bool wxGIFHandler::SaveFile( wxImage * WXUNUSED(image),
 109                              wxOutputStream& WXUNUSED(stream), bool verbose )
 110 {
 111     if (verbose)
 112         wxLogDebug(wxT("GIF: the handler is read-only!!"));
 113
 114     return false;
 115 }
 116
 117 bool wxGIFHandler::DoCanRead( wxInputStream& stream )
 118 {
 119     wxGIFDecoder decod(&stream);
 120     return decod.CanRead();
 121 }
 122
 123 #endif  // wxUSE_STREAMS
 124
 125 #endif  // wxUSE_GIF