oops, undid last commit, the extra test is unneded (but a comment explaining why...

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

diff --git a/src/common/imaggif.cpp b/src/common/imaggif.cpp
index 07a1067ca30469815187d96b1af7466042501b0a..19b164b1b20720e10213715b32c10b7994252901 100644 (file)
--- a/src/common/imaggif.cpp
+++ b/src/common/imaggif.cpp
@@ -7,10 +7,6 @@
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-#ifdef __GNUG__
-#pragma implementation "imaggif.h"
-#endif
-
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
@@ -22,7 +18,7 @@
 #  include "wx/defs.h"
 #endif
 
-#if wxUSE_GIF
+#if wxUSE_IMAGE && wxUSE_GIF
 
 #include "wx/imaggif.h"
 #include "wx/gifdecod.h"
@@ -38,33 +34,70 @@ 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;
+    bool ok = true;
 
-    decod = new wxGIFDecoder(&stream, TRUE);
+//    image->Destroy();
+    decod = new wxGIFDecoder(&stream, true);
+    error = decod->ReadGIF();
 
-    if ((error = decod->ReadGIF()) != wxGIF_OK)
+    if ((error != wxGIF_OK) && (error != wxGIF_TRUNCATED))
     {
         if (verbose)
         {
             switch (error)
             {
-                case wxGIF_INVFORMAT: wxLogError(_("wxGIFHandler: error in GIF image format")); break;
-                case wxGIF_MEMERR:    wxLogError(_("wxGIFHandler: couldn't allocate enough memory")); break;
-                default:              wxLogError(_("wxGIFHandler: 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 */
+    }
+
+    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);
+        }
     }
 
-    image->Destroy();
-    ok = decod->ConvertToImage(image);
+    if (ok)
+    {
+        ok = decod->ConvertToImage(image);
+    }
+    else
+    {
+        wxLogError(_("GIF: Invalid gif index."));
+    }
 
     delete decod;
+
     return ok;
 }
 
@@ -72,21 +105,15 @@ 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;
-
-    decod = new wxGIFDecoder(&stream);
-    ok = decod->CanRead();
-
-    delete decod;
-    return ok;
+    wxGIFDecoder decod(&stream);
+    return decod.CanRead();
 }
 
 #endif  // wxUSE_STREAMS