+ /* We want to know what would be the
+ y-position of the next bound (relative to my y-parent) if it belonged
+ to the same system as this bound. We rely on the fact that
+ the y-parent of the next bound is a spanner (probably the
+ VerticalAxisGroup of a staff) that extends over the break.
+ */
+ Spanner *next_bound_parent_on_this_line =
+ next_bound_parent->broken_neighbor (other_dir (dir));
+
+ if (next_bound_parent_on_this_line)
+ {
+ Grob *common = me->common_refpoint (next_bound_parent_on_this_line, Y_AXIS);
+ Real bound_offset = next_bound_parent_on_this_line->relative_coordinate (common, Y_AXIS);
+ y = next_ext.center () + bound_offset - me->relative_coordinate (common, Y_AXIS);
+ }
+ else
+ {
+ /* We fall back to assuming that the distance between staves doesn't
+ change over line breaks. */
+ programming_error ("next-bound's parent doesn't extend to this line");
+ Grob *next_system = next_bound->get_system ();
+ Grob *this_system = me->get_system ();
+ y = next_ext.center () + next_bound_parent->relative_coordinate (next_system, Y_AXIS)
+ - me->relative_coordinate (this_system, Y_AXIS);
+ }