2 This file is part of LilyPond, the GNU music typesetter.
4 Copyright (C) 2010--2015 Joe Neeman <joeneeman@gmail.com>
6 LilyPond is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 LilyPond is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with LilyPond. If not, see <http://www.gnu.org/licenses/>.
21 #include "dispatcher.hh"
22 #include "engraver.hh"
24 #include "grob-array.hh"
26 #include "translator.icc"
30 class Keep_alive_together_engraver: public Engraver
32 vector<Grob *> group_spanners_;
35 TRANSLATOR_DECLARATIONS (Keep_alive_together_engraver);
36 DECLARE_ACKNOWLEDGER (hara_kiri_group_spanner);
38 virtual void finalize ();
41 Keep_alive_together_engraver::Keep_alive_together_engraver ()
46 Keep_alive_together_engraver::acknowledge_hara_kiri_group_spanner (Grob_info i)
48 group_spanners_.push_back (i.grob ());
52 Keep_alive_together_engraver::finalize ()
54 for (vsize i = 0; i < group_spanners_.size (); ++i)
56 SCM this_layer = group_spanners_[i]->get_property ("remove-layer");
57 if (scm_is_false (this_layer))
60 SCM live_scm = Grob_array::make_array ();
61 Grob_array *live = unsmob<Grob_array> (live_scm);
62 SCM dead_scm = Grob_array::make_array ();
63 Grob_array *dead = unsmob<Grob_array> (dead_scm);
65 for (vsize j = 0; j < group_spanners_.size (); ++j)
69 SCM that_layer = group_spanners_[j]->get_property ("remove-layer");
70 if (scm_is_false (that_layer))
72 if (!scm_is_integer (this_layer))
74 // Unspecified layers are kept alive by anything else
75 live->add (group_spanners_[j]);
78 // an explicit layer is only affected by explicit layers
79 if (!scm_is_integer (that_layer))
81 if (scm_is_true (scm_num_eq_p (that_layer, this_layer)))
82 live->add (group_spanners_[j]);
83 else if (scm_is_true (scm_less_p (that_layer, this_layer)))
84 dead->add (group_spanners_[j]);
87 group_spanners_[i]->set_object ("keep-alive-with", live_scm);
89 group_spanners_[i]->set_object ("make-dead-when", dead_scm);
93 ADD_ACKNOWLEDGER (Keep_alive_together_engraver, hara_kiri_group_spanner);
95 ADD_TRANSLATOR (Keep_alive_together_engraver,
97 "This engraver collects all @code{Hara_kiri_group_spanner}s "
98 "that are created in contexts at or below its own. "
99 "These spanners are then tied together so that one will "
100 "be removed only if all are removed. For example, "
101 "if a @code{StaffGroup} uses this engraver, then the staves "
102 "in the group will all be visible as long as there is a note "
103 "in at least one of them.",