+ // GetThemeTextDimensions will cache strings and the documentation
+ // says not to use the NoCopy string creation calls.
+ // This also means that we can't use CFSTR without
+ // -fno-constant-cfstrings if the library might be unloaded,
+ // as GetThemeTextDimensions may cache a pointer to our
+ // unloaded segment.
+ wxCFStringRef str( !m_label.empty() ? m_label : wxString(" "),
+ GetFont().GetEncoding() );