+ for (vsize i = 0; i < elts.size (); i++)
+ {
+ Item *il = dynamic_cast<Item *> (elts[i]);
+ if (pc != il->get_column ())
+ continue;
+
+ /* ugh. We want to exclude groups of grobs (so that we insert each grob
+ individually into the skyline instead of adding a single box that
+ bounds all of them). However, we can't exclude an axis-group that
+ adds to its childrens' stencil. Currently, this is just TrillPitchGroup;
+ hence the check for note-head-interface. */
+ if (Axis_group_interface::has_interface (il)
+ && !Note_head::has_interface (il))
+ continue;
+
+ Interval y (il->pure_height (ycommon, 0, very_large));
+ Interval x (il->extent (pc, X_AXIS));
+
+ Interval extra_width = robust_scm2interval (elts[i]->get_property ("extra-spacing-width"),
+ Interval (-0.1, 0.1));
+ Interval extra_height = robust_scm2interval (elts[i]->get_property ("extra-spacing-height"),
+ Interval (0.0, 0.0));
+
+ x[LEFT] += extra_width[LEFT];
+ x[RIGHT] += extra_width[RIGHT];
+ y[DOWN] += extra_height[DOWN];
+ y[UP] += extra_height[UP];
+
+ if (!x.is_empty () && !y.is_empty ())
+ out.push_back (Box (x, y));
+ }