Rewind the input stream after failing to load image from it.

[wxWidgets.git] / src / common / imaggif.cpp

diff --git a/src/common/imaggif.cpp b/src/common/imaggif.cpp
index eec1778dcbb5380df81ddad94a34a1f65ec59a98..fdb9a4971d1af78c4521d8d47c9fe2bb64c1d961 100644 (file)
--- a/src/common/imaggif.cpp
+++ b/src/common/imaggif.cpp
@@ -1,5 +1,5 @@
 /////////////////////////////////////////////////////////////////////////////
-// Name:        imaggif.cpp
+// Name:        src/common/imaggif.cpp
 // Purpose:     wxGIFHandler
 // Author:      Vaclav Slavik & Guillermo Rodriguez Garcia
 // RCS-ID:      $Id$
@@ -7,33 +7,25 @@
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-/*
-  We don't put pragma implement in this file because it is already present in
-  src/common/image.cpp
-*/
-
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
-#  pragma hdrstop
+    #pragma hdrstop
 #endif
 
+#if wxUSE_IMAGE && wxUSE_GIF
+
 #ifndef WX_PRECOMP
-#  include "wx/defs.h"
+    #include "wx/intl.h"
+    #include "wx/log.h"
 #endif
 
-#if wxUSE_GIF
-
-#include "wx/image.h"
+#include "wx/imaggif.h"
 #include "wx/gifdecod.h"
 #include "wx/wfstream.h"
-#include "wx/log.h"
-#include "wx/intl.h"
 
-#if !USE_SHARED_LIBRARIES
 IMPLEMENT_DYNAMIC_CLASS(wxGIFHandler,wxImageHandler)
-#endif
 
 //-----------------------------------------------------------------------------
 // wxGIFHandler
@@ -41,33 +33,55 @@ IMPLEMENT_DYNAMIC_CLASS(wxGIFHandler,wxImageHandler)
 
 #if wxUSE_STREAMS
 
-bool wxGIFHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose, int WXUNUSED(index) )
+bool wxGIFHandler::LoadFile(wxImage *image, wxInputStream& stream,
+                            bool verbose, int index)
 {
     wxGIFDecoder *decod;
-    int error;
-    bool ok;
+    wxGIFErrorCode error;
+    bool ok = true;
 
-    decod = new wxGIFDecoder(&stream, TRUE);
+//    image->Destroy();
+    decod = new wxGIFDecoder();
+    error = decod->LoadGIF(stream);
 
-    if ((error = decod->ReadGIF()) != E_OK)
+    if ((error != wxGIF_OK) && (error != wxGIF_TRUNCATED))
     {
         if (verbose)
         {
             switch (error)
             {
-                case E_FORMATO: wxLogError(_("GIF: Error in image format.")); break;
-                case E_MEMORIA: wxLogError(_("GIF: Couldn't allocate memory.")); break;
-                default:        wxLogError(_("GIF: Unknown error."));
+                case wxGIF_INVFORMAT:
+                    wxLogError(_("GIF: error in GIF image format."));
+                    break;
+                case wxGIF_MEMERR:
+                    wxLogError(_("GIF: not enough memory."));
+                    break;
+                default:
+                    wxLogError(_("GIF: unknown error!!!"));
+                    break;
             }
         }
         delete decod;
-        return FALSE;
+        return false;
+    }
+
+    if ((error == wxGIF_TRUNCATED) && verbose)
+    {
+        wxLogError(_("GIF: data stream seems to be truncated."));
+        /* go on; image data is OK */
     }
 
-    image->Destroy();
-    ok = decod->ConvertToImage(image);
+    if (ok)
+    {
+        ok = decod->ConvertToImage(index != -1 ? (size_t)index : 0, image);
+    }
+    else
+    {
+        wxLogError(_("GIF: Invalid gif index."));
+    }
 
     delete decod;
+
     return ok;
 }
 
@@ -75,21 +89,31 @@ bool wxGIFHandler::SaveFile( wxImage * WXUNUSED(image),
                              wxOutputStream& WXUNUSED(stream), bool verbose )
 {
     if (verbose)
-        wxLogDebug(wxT("wxGIFHandler is read-only!!"));
+    {
+        wxLogDebug(wxT("GIF: the handler is read-only!!"));
+    }
 
-    return FALSE;
+    return false;
 }
 
 bool wxGIFHandler::DoCanRead( wxInputStream& stream )
 {
-    wxGIFDecoder *decod;
-    bool ok;
+    wxGIFDecoder decod;
+    return decod.CanRead(stream);
+         // it's ok to modify the stream position here
+}
 
-    decod = new wxGIFDecoder(&stream);
-    ok = decod->CanRead();
+int wxGIFHandler::DoGetImageCount( wxInputStream& stream )
+{
+    wxGIFDecoder decod;
+    wxGIFErrorCode error = decod.LoadGIF(stream);
+    if ( (error != wxGIF_OK) && (error != wxGIF_TRUNCATED) )
+        return -1;
 
-    delete decod;
-    return ok;
+    // NOTE: this function modifies the current stream position but it's ok
+    //       (see wxImageHandler::GetImageCount)
+
+    return decod.GetFrameCount();
 }
 
 #endif  // wxUSE_STREAMS