-/*
- Find a common Y parent, which --if found-- should be the
- fixed-distance alignment.
-*/
-Grob *
-line_spanner_common_parent (Grob *me)
-{
- Grob *common = find_fixed_alignment_parent (me);
- if (!common)
- {
- common = Staff_symbol_referencer::get_staff_symbol (me);
- if (common)
- common = common->get_parent (Y_AXIS);
+ Grob *common_y = me->common_refpoint (me->get_bound (dir), Y_AXIS);
+ if (me->get_bound (dir)->break_status_dir ())
+ {
+ Spanner *next_sp = me->broken_neighbor (dir);
+ Item *next_bound = next_sp->get_bound (dir);
+
+ if (next_bound->break_status_dir ())
+ {
+ programming_error ("no note heads for the line spanner on neighbor line?"
+ " Confused.");
+ me->suicide ();
+ return SCM_EOL;
+ }
+
+ Spanner *next_bound_parent = parent_spanner (next_bound);
+ Interval next_ext = next_bound->extent (next_bound_parent, Y_AXIS);
+
+ /* 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);
+ }
+ }