extract_grob_set (me, "columns", cols);
Grob *commony = common_refpoint_of_array (cols, me, Y_AXIS);
extract_grob_set (me, "columns", cols);
Grob *commony = common_refpoint_of_array (cols, me, Y_AXIS);
Interval v = robust_scm2interval (me->get_property ("positions"),
Interval (0, 0));
return ly_interval2scm (Staff_symbol_referencer::staff_space (me) * 0.5 * v);
Interval v = robust_scm2interval (me->get_property ("positions"),
Interval (0, 0));
return ly_interval2scm (Staff_symbol_referencer::staff_space (me) * 0.5 * v);