+ int sri[] = {0, 0};
+ Grob *gs[] = {g1, g2};
+
+ for (int i = 0; i < 2; i++)
+ {
+ sri[i] = gs[i]->spanned_rank_interval ()[LEFT];
+ if (Spanner *s = dynamic_cast<Spanner *> (gs[i]))
+ {
+ if (s->broken_intos_.size ())
+ s = (scm_to_int (s->broken_intos_[0]->get_property ("spanner-placement")) == LEFT
+ ? s->broken_intos_[0]
+ : s->broken_intos_.back ());
+ gs[i] = s;
+ if (robust_scm2double (s->get_property ("X-offset"), 0.0) > 0)
+ sri[i] = s->spanned_rank_interval ()[RIGHT];
+ }
+ }
+
+ if (sri[0] == sri[1])
+ return Grob::vertical_less (gs[0], gs[1]);
+
+ return sri[0] < sri[1];
+}
+
+MAKE_SCHEME_CALLBACK (System, footnotes_before_line_breaking, 1);
+SCM
+System::footnotes_before_line_breaking (SCM smob)
+{
+ Grob *me = unsmob<Grob> (smob);
+ vector<Grob *> footnotes;
+ SCM grobs_scm = Grob_array::make_array ();
+ extract_grob_set (me, "all-elements", elts);
+ for (vsize i = 0; i < elts.size (); i++)
+ if (elts[i]->internal_has_interface (ly_symbol2scm ("footnote-interface")))
+ footnotes.push_back (elts[i]);
+
+ unsmob<Grob_array> (grobs_scm)->set_array (footnotes);
+ return grobs_scm;
+}
+
+MAKE_SCHEME_CALLBACK (System, footnotes_after_line_breaking, 1);
+SCM
+System::footnotes_after_line_breaking (SCM smob)
+{
+ Spanner *sys_span = unsmob<Spanner> (smob);
+ System *sys = dynamic_cast<System *> (sys_span);
+ Interval_t<int> sri = sys->spanned_rank_interval ();
+ vector<Grob *> footnote_grobs = sys->get_footnote_grobs_in_range (sri[LEFT], sri[RIGHT]);
+ vector_sort (footnote_grobs, grob_2D_less);
+
+ SCM grobs_scm = Grob_array::make_array ();
+ unsmob<Grob_array> (grobs_scm)->set_array (footnote_grobs);
+ return grobs_scm;
+}
+
+MAKE_SCHEME_CALLBACK (System, vertical_skyline_elements, 1);
+SCM
+System::vertical_skyline_elements (SCM smob)
+{
+ Grob *me_grob = unsmob<Grob> (smob);
+ vector<Grob *> vertical_skyline_grobs;
+ extract_grob_set (me_grob, "elements", my_elts);
+ for (vsize i = 0; i < my_elts.size (); i++)
+ if (has_interface<System_start_delimiter> (my_elts[i]))
+ vertical_skyline_grobs.push_back (my_elts[i]);
+
+ System *me = dynamic_cast<System *> (me_grob);
+ Grob *align = unsmob<Grob> (me->get_object ("vertical-alignment"));
+ if (!align)
+ {
+ SCM grobs_scm = Grob_array::make_array ();
+ unsmob<Grob_array> (grobs_scm)->set_array (vertical_skyline_grobs);
+ return grobs_scm;
+ }
+
+ extract_grob_set (align, "elements", elts);
+
+ for (vsize i = 0; i < elts.size (); i++)
+ if (has_interface<Hara_kiri_group_spanner> (elts[i]))
+ vertical_skyline_grobs.push_back (elts[i]);
+
+ SCM grobs_scm = Grob_array::make_array ();
+ unsmob<Grob_array> (grobs_scm)->set_array (vertical_skyline_grobs);
+ return grobs_scm;