#include "wx/colour.h"
#include "wx/gdicmn.h"
+#include "wx/log.h"
+#include "wx/stream.h"
-class WXDLLIMPEXP_FWD_BASE wxInputStream;
class WXDLLIMPEXP_FWD_CORE wxImage;
/*
}
virtual bool Load( wxInputStream& stream ) = 0;
- virtual bool CanRead( wxInputStream& stream ) const = 0;
+
+ bool CanRead( wxInputStream& stream ) const
+ {
+ // NOTE: this code is the same of wxImageHandler::CallDoCanRead
+
+ if ( !stream.IsSeekable() )
+ return false; // can't test unseekable stream
+
+ wxFileOffset posOld = stream.TellI();
+ bool ok = DoCanRead(stream);
+
+ // restore the old position to be able to test other formats and so on
+ if ( stream.SeekI(posOld) == wxInvalidOffset )
+ {
+ wxLogDebug(wxT("Failed to rewind the stream in wxAnimationDecoder!"));
+
+ // reading would fail anyhow as we're not at the right position
+ return false;
+ }
+
+ return ok;
+ }
virtual wxAnimationDecoder *Clone() const = 0;
virtual wxAnimationType GetType() const = 0;
unsigned int GetFrameCount() const { return m_nFrames; }
protected:
+ // checks the signature of the data in the given stream and returns true if it
+ // appears to be a valid animation format recognized by the animation decoder;
+ // this function should modify the stream current position without taking care
+ // of restoring it since CanRead() will do it.
+ virtual bool DoCanRead(wxInputStream& stream) const = 0;
+
wxSize m_szAnimation;
unsigned int m_nFrames;