+
+
+/*
+ Make sure that the left and right bounds encompasses all objects it
+ points to.
+
+ TODO: maybe be more specific. Most probably fucks up if someone sets
+ a pointer to the staff symbol in S
+*/
+void
+extend_spanner_over_elements (Grob*s)
+{
+ Spanner*sp = dynamic_cast<Spanner*> (s);
+
+ SCM s1 = sp->get_bound (LEFT) ? sp->get_bound (LEFT)->self_scm () : SCM_EOL;
+ SCM s2 = sp->get_bound (RIGHT) ? sp->get_bound (RIGHT)->self_scm () : SCM_EOL;
+
+ SCM pair = gh_cons (s1,s2);
+ extend_spanner_over_elements (sp->mutable_property_alist_, pair);
+
+ Grob *p1 = unsmob_grob (ly_car (pair));
+ Grob* p2 = unsmob_grob (ly_cdr (pair));
+ sp->set_bound (LEFT,p1);
+ sp->set_bound (RIGHT, p2);
+}
+
+
+MAKE_SCHEME_CALLBACK (Spanner,set_spacing_rods,1);
+SCM
+Spanner::set_spacing_rods (SCM smob)
+{
+ Grob*me = unsmob_grob (smob);
+
+ Rod r;
+ Spanner*sp = dynamic_cast<Spanner*> (me);
+ r.item_l_drul_[LEFT] = sp->get_bound (LEFT);
+ r.item_l_drul_[RIGHT] = sp->get_bound (RIGHT);
+ r.distance_f_ =
+ gh_scm2double (me->get_grob_property ("minimum-length"))
+ * 1.0;
+
+ r.add_to_cols ();
+ return SCM_UNSPECIFIED;
+}
+
+
+Spanner*
+unsmob_spanner (SCM s )
+{
+ return dynamic_cast<Spanner*> (unsmob_grob (s));
+}
+
+ADD_INTERFACE(Spanner,
+ "spanner-interface",
+ "",
+ "minimum-length");