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 19b164b1b20720e10213715b32c10b7994252901..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:      $Id$
@@ -11,20 +11,19 @@
 #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_IMAGE && wxUSE_GIF
-
 #include "wx/imaggif.h"
 #include "wx/gifdecod.h"
 #include "wx/wfstream.h"
-#include "wx/log.h"
-#include "wx/intl.h"
 
 IMPLEMENT_DYNAMIC_CLASS(wxGIFHandler,wxImageHandler)
 
@@ -38,12 +37,12 @@ bool wxGIFHandler::LoadFile(wxImage *image, wxInputStream& stream,
                             bool verbose, int index)
 {
     wxGIFDecoder *decod;
-    int error;
+    wxGIFErrorCode error;
     bool ok = true;
 
 //    image->Destroy();
-    decod = new wxGIFDecoder(&stream, true);
-    error = decod->ReadGIF();
+    decod = new wxGIFDecoder();
+    error = decod->LoadGIF(stream);
 
     if ((error != wxGIF_OK) && (error != wxGIF_TRUNCATED))
     {
@@ -72,24 +71,9 @@ bool wxGIFHandler::LoadFile(wxImage *image, wxInputStream& stream,
         /* go on; image data is OK */
     }
 
-    if (index != -1)
-    {
-        // We're already on index = 0 by default. So no need
-        // to call GoFrame(0) then. On top of that GoFrame doesn't
-        // accept an index of 0. (Instead GoFirstFrame() should be used)
-        // Also if the gif image has only one frame, calling GoFrame(0)
-        // fails because GoFrame() only works with gif animations.
-        // (It fails if IsAnimation() returns false)
-        // All valid reasons to NOT call GoFrame when index equals 0.
-        if (index != 0)
-        {
-            ok = decod->GoFrame(index);
-        }
-    }
-
     if (ok)
     {
-        ok = decod->ConvertToImage(image);
+        ok = decod->ConvertToImage(index != -1 ? (size_t)index : 0, image);
     }
     else
     {
@@ -105,15 +89,31 @@ bool wxGIFHandler::SaveFile( wxImage * WXUNUSED(image),
                              wxOutputStream& WXUNUSED(stream), bool verbose )
 {
     if (verbose)
+    {
         wxLogDebug(wxT("GIF: the handler is read-only!!"));
+    }
 
     return false;
 }
 
 bool wxGIFHandler::DoCanRead( wxInputStream& stream )
 {
-    wxGIFDecoder decod(&stream);
-    return decod.CanRead();
+    wxGIFDecoder decod;
+    return decod.CanRead(stream);
+         // it's ok to modify the stream position here
+}
+
+int wxGIFHandler::DoGetImageCount( wxInputStream& stream )
+{
+    wxGIFDecoder decod;
+    wxGIFErrorCode error = decod.LoadGIF(stream);
+    if ( (error != wxGIF_OK) && (error != wxGIF_TRUNCATED) )
+        return -1;
+
+    // NOTE: this function modifies the current stream position but it's ok
+    //       (see wxImageHandler::GetImageCount)
+
+    return decod.GetFrameCount();
 }
 
 #endif  // wxUSE_STREAMS