+ static Stencil compound_barline (Grob *, String, Real height);
+ static Stencil simple_barline (Grob *, Real wid, Real height);
+ DECLARE_SCHEME_CALLBACK (get_staff_bar_size, (SCM));
+ DECLARE_SCHEME_CALLBACK (print, (SCM));
+ DECLARE_SCHEME_CALLBACK (before_line_breaking, (SCM));