+void
+Break_align_interface::do_alignment (Grob *me)
+{
+ Item * item = dynamic_cast<Item*> (me);
+ Item *column = item->column_l ();
+
+ Link_array<Grob> elems;
+ Link_array<Grob> all_elems
+ = Pointer_group_interface__extract_elements (me, (Grob*)0,
+ "elements");
+
+ for (int i=0; i < all_elems.size(); i++)
+ {
+ Interval y = all_elems[i]->extent(all_elems[i], X_AXIS);
+ if (!y.empty_b())
+ elems.push (dynamic_cast<Grob*> (all_elems[i]));
+ }
+
+ if (!elems.size ())
+ return;
+
+ SCM symbol_list = SCM_EOL;
+ Array<Real> dists;
+ SCM current_origin = ly_symbol2scm ("none");
+ for (int i=0; i <= elems.size (); i++)
+ {
+ Grob *next_elt = i < elems.size ()
+ ? elems[i]
+ : 0 ;
+
+ SCM next_origin;
+
+ if (next_elt)
+ {
+ next_origin = next_elt->get_grob_property ("break-align-symbol");
+ next_origin =
+ gh_symbol_p (next_origin)?
+ next_origin : ly_symbol2scm ("none")
+;
+ }
+ else
+ next_origin = ly_symbol2scm ("begin-of-note");
+
+ SCM alist = me->get_grob_property ("space-alist");
+ SCM e = scm_assoc (scm_listify (current_origin,
+ next_origin,
+ SCM_UNDEFINED), alist);
+
+ SCM extra_space;
+ if (e != SCM_BOOL_F)
+ {
+ extra_space = gh_cdr (e);
+ }
+ else
+ {
+ warning (_f ("unknown spacing pair `%s', `%s'",
+ ly_symbol2string (current_origin),
+ ly_symbol2string (next_origin)));
+ extra_space = scm_listify (ly_symbol2scm ("minimum-space"), gh_double2scm (0.0), SCM_UNDEFINED);
+ }
+
+ SCM symbol = gh_car (extra_space);
+ Real spc = gh_scm2double (gh_cadr(extra_space));
+
+ dists.push(spc);
+ symbol_list = gh_cons (symbol, symbol_list);
+ current_origin = next_origin;
+ }
+
+
+ // skip the first sym.
+ symbol_list = gh_cdr (scm_reverse (symbol_list));
+ for (int i=0; i <elems.size()-1; i++)
+ {
+ elems[i]->set_grob_property (gh_car (symbol_list),
+ scm_cons (gh_double2scm (0),
+ gh_double2scm (dists[i+1])));
+
+ symbol_list = gh_cdr (symbol_list);
+ }
+
+
+ // urg
+ SCM first_pair = elems[0]->get_grob_property ("minimum-space");
+ if (gh_pair_p (first_pair))
+ first_pair = first_pair;
+ else
+ first_pair = gh_cons (gh_double2scm (0.0), gh_double2scm (0.0));
+
+ scm_set_car_x (first_pair, gh_double2scm (-dists[0]));
+ elems[0]->set_grob_property ("minimum-space", first_pair);
+
+
+ /*
+ Force callbacks for alignment to be called
+ */
+ Align_interface::align_to_extents (me, X_AXIS);
+
+ Real pre_space = elems[0]->relative_coordinate (column, X_AXIS);
+
+ Real xl = elems[0]->extent (elems[0],X_AXIS)[LEFT];
+ if (!isinf (xl))
+ pre_space += xl;
+ else
+ programming_error ("Infinity reached. ");
+
+ Real xr = elems.top ()->extent (elems.top (), X_AXIS)[RIGHT];
+ Real spring_len = elems.top ()->relative_coordinate (column, X_AXIS);
+ if (!isinf (xr))
+ spring_len += xr;
+ else
+ programming_error ("Infinity reached.");
+
+ Real stretch_distance =0.;
+
+ if (gh_car (symbol_list) == ly_symbol2scm ("extra-space"))
+ {
+ spring_len += dists.top ();
+ stretch_distance = dists.top ();
+ }
+ else if (gh_car (symbol_list) == ly_symbol2scm ("minimum-space"))
+ {
+ spring_len = spring_len >? dists.top ();
+ stretch_distance = spring_len;
+ }
+
+ /*
+ Hint the spacing engine how much space to put in.
+
+ The pairs are in the format of an interval (ie. CAR < CDR).
+ */
+ column->set_grob_property ("extra-space",
+ scm_cons (gh_double2scm (pre_space),
+ gh_double2scm (spring_len)));
+
+ column->set_grob_property ("stretch-distance",
+ gh_cons (gh_double2scm (-dists[0]),
+ gh_double2scm (stretch_distance)));
+}
+
+
+void
+Break_align_interface::set_interface (Grob*me)
+{
+ Align_interface::set_interface (me);
+ Align_interface::set_axis (me,X_AXIS);
+
+
+}