Approximates cross-staff slurs in VerticalAxisGroup vertical-skylines.

lily/melody-engraver.cc

 /*
   This file is part of LilyPond, the GNU music typesetter.
 
   Copyright (C) 1997--2012 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
 
@@ skipping 54 matching lines @@
 
           Melody_spanner::add_stem (melody_item_, stem_);
         }
     }
   stem_ = 0;
 }
 
 void
 Melody_engraver::acknowledge_slur (Grob_info info)
 {
-  if (!info.grob ()->internal_has_interface (ly_symbol2scm ("slur-stub-interface")))
+  if (!info.grob ()->internal_has_interface (ly_symbol2scm ("cross-staff-stub-interface")))
     melody_item_ = 0;
 }
 
 void
 Melody_engraver::acknowledge_stem (Grob_info info)
 {
   stem_ = info.grob ();
 }
 
 #include "translator.icc"
 
 ADD_ACKNOWLEDGER (Melody_engraver, stem);
 ADD_ACKNOWLEDGER (Melody_engraver, slur);
 
 ADD_TRANSLATOR (Melody_engraver,
                 /* doc */
                 "Create information for context dependent typesetting"
                 " decisions.",
 
                 /* create */
                 "MelodyItem ",
 
                 /* read */
                 "",
 
                 /* write */
                 ""
                );