X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/d8359d3ca077993d3ef61d6c09000ce7beeb577b..f6669958924c3c3833e2932b65598b06073d2e65:/include/wx/animdecod.h diff --git a/include/wx/animdecod.h b/include/wx/animdecod.h index a4c864c365..876c802520 100644 --- a/include/wx/animdecod.h +++ b/include/wx/animdecod.h @@ -16,8 +16,9 @@ #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; /* @@ -93,7 +94,28 @@ public: } 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; @@ -129,6 +151,12 @@ public: 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;