2 auto-change-iterator.cc -- implement Auto_change_iterator
4 source file of the GNU LilyPond music typesetter
6 (c) 1999--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
11 #include "auto-change-iterator.hh"
12 #include "translator-group.hh"
18 Auto_change_iterator::change_to (Music_iterator *it, SCM to_type_sym,
21 Translator_group * current = it->report_to ();
22 Translator_group * last = 0;
25 Cut & Paste from Change_iterator (ugh).
27 TODO: abstract this function
30 /* find the type of translator that we're changing.
32 If \translator Staff = bass, then look for Staff = *
34 while (current && !current->is_alias_b (to_type_sym))
37 current = current->daddy_trans_;
40 if (current && current->id_string_ == to_id)
43 msg += _ ("Can't switch translators, I'm there already");
49 Translator_group * dest =
50 it->report_to ()->find_create_translator (to_type_sym, to_id);
51 current->remove_translator (last);
52 dest->add_used_group_translator (last);
57 We could change the current translator's id, but that would make
60 last->translator_id_string_ = get_change ()->change_to_id_string_;
62 // error (_ ("I'm one myself"));
65 ; // error (_ ("none of these in my family"));
70 Look ahead to find first pitches to determine staff position.
71 WARNING: this means that
73 \autochange Staff \notes { .... \context Staff = otherstaff { .. } .. }
75 will confuse the autochanger, since it will not notice that the
76 music for OTHERSTAFF is not his.
78 PRECONDITION: this->ok () holds.
81 Auto_change_iterator::pending_pitch (Moment m) const
83 Music_iterator * iter = child_iter_ ->clone ();
87 SCM muses = iter->get_pending_events (m);
88 for (SCM s = muses; gh_pair_p (s); s=ly_cdr (s))
90 Music * m = unsmob_music (ly_car (s));
91 if (m && m->is_mus_type ("note-event"))
93 ps.push (*unsmob_pitch (m->get_mus_property ("pitch")));
104 m = iter->pending_moment ();
107 scm_gc_unprotect_object (iter->self_scm());
113 Auto_change_iterator::process (Moment m)
116 first we get the pitches, then we do the real work.
117 Music_wrapper_iterator::process () might process (and throw away)
119 Array<Pitch> ps = pending_pitch (m);
121 Music_wrapper_iterator::process (m);
125 Direction s = Direction (sign (p.steps ()));
127 Don't change for central C.
129 TODO: make this tunable somehow. Sometimes, you'd want to
130 switch for C.C. as well.
133 if (s && s != where_dir_)
136 String to_id = (s >= 0) ? "up" : "down";
137 change_to (child_iter_, get_music ()->get_mus_property ("what"), to_id);
142 Auto_change_iterator::Auto_change_iterator ()
147 IMPLEMENT_CTOR_CALLBACK (Auto_change_iterator);