lily/key-engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2010 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   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.
  10
  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.
  15
  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/>.
  18 */
  19
  20 #include "bar-line.hh"
  21 #include "clef.hh"
  22 #include "context.hh"
  23 #include "engraver.hh"
  24 #include "item.hh"
  25 #include "pitch.hh"
  26 #include "protected-scm.hh"
  27 #include "staff-symbol-referencer.hh"
  28 #include "stream-event.hh"
  29
  30 #include "translator.icc"
  31
  32 class Key_engraver : public Engraver
  33 {
  34   void create_key (bool);
  35   void read_event (Stream_event const *r);
  36
  37   Stream_event *key_event_;
  38   Item *item_;
  39   Item *cancellation_;
  40 public:
  41   TRANSLATOR_DECLARATIONS (Key_engraver);
  42
  43 protected:
  44   virtual void initialize ();
  45   virtual void finalize ();
  46   void stop_translation_timestep ();
  47   void process_music ();
  48
  49   DECLARE_TRANSLATOR_LISTENER (key_change);
  50   DECLARE_ACKNOWLEDGER (clef);
  51   DECLARE_ACKNOWLEDGER (bar_line);
  52 };
  53
  54 void
  55 Key_engraver::finalize ()
  56 {
  57 }
  58
  59 Key_engraver::Key_engraver ()
  60 {
  61   key_event_ = 0;
  62   item_ = 0;
  63   cancellation_ = 0;
  64 }
  65
  66
  67 void
  68 Key_engraver::create_key (bool is_default)
  69 {
  70   if (!item_)
  71     {
  72       item_ = make_item ("KeySignature",
  73                          key_event_ ? key_event_->self_scm () : SCM_EOL);
  74
  75       item_->set_property ("c0-position",
  76                            get_property ("middleCPosition"));
  77
  78       SCM last = get_property ("lastKeySignature");
  79       SCM key = get_property ("keySignature");
  80       bool extranatural = to_boolean (get_property ("extraNatural"));
  81
  82       if ((to_boolean (get_property ("printKeyCancellation"))
  83            || key == SCM_EOL)
  84           && !scm_is_eq (last, key))
  85         {
  86           SCM restore = SCM_EOL;
  87           SCM *tail = &restore;
  88           for (SCM s = last; scm_is_pair (s); s = scm_cdr (s))
  89             {
  90               SCM new_alter_pair = scm_assoc (scm_caar (s), key);
  91               Rational old_alter = robust_scm2rational (scm_cdar (s), 0);
  92               if (new_alter_pair == SCM_BOOL_F
  93                   || (extranatural
  94                       && (ly_scm2rational (scm_cdr (new_alter_pair)) - old_alter)*old_alter
  95                           < Rational (0)))
  96                 {
  97                   *tail = scm_cons (scm_car (s), *tail);
  98                   tail = SCM_CDRLOC (*tail);
  99                 }
 100             }
 101
 102           if (scm_is_pair (restore))
 103             {
 104               cancellation_ = make_item ("KeyCancellation",
 105                                          key_event_
 106                                          ? key_event_->self_scm () : SCM_EOL);
 107
 108               cancellation_->set_property ("alteration-alist", scm_reverse (restore));
 109               cancellation_->set_property ("c0-position",
 110                                            get_property ("middleCPosition"));
 111             }
 112         }
 113
 114       item_->set_property ("alteration-alist", scm_reverse (key));
 115     }
 116
 117   if (!is_default)
 118     {
 119       SCM visibility = get_property ("explicitKeySignatureVisibility");
 120       item_->set_property ("break-visibility", visibility);
 121     }
 122 }
 123
 124 IMPLEMENT_TRANSLATOR_LISTENER (Key_engraver, key_change);
 125 void
 126 Key_engraver::listen_key_change (Stream_event *ev)
 127 {
 128   /* do this only once, just to be on the safe side.  */
 129   if (ASSIGN_EVENT_ONCE (key_event_, ev))
 130     read_event (key_event_);
 131 }
 132
 133 void
 134 Key_engraver::acknowledge_clef (Grob_info /* info */)
 135 {
 136   SCM c = get_property ("createKeyOnClefChange");
 137   if (to_boolean (c))
 138     create_key (false);
 139 }
 140
 141 void
 142 Key_engraver::acknowledge_bar_line (Grob_info /* info */)
 143 {
 144   if (scm_is_pair (get_property ("keySignature")))
 145     create_key (true);
 146 }
 147
 148 void
 149 Key_engraver::process_music ()
 150 {
 151   if (key_event_
 152       || get_property ("lastKeySignature") != get_property ("keySignature"))
 153     create_key (false);
 154 }
 155
 156 void
 157 Key_engraver::stop_translation_timestep ()
 158 {
 159   item_ = 0;
 160   context ()->set_property ("lastKeySignature", get_property ("keySignature"));
 161   cancellation_ = 0;
 162   key_event_ = 0;
 163 }
 164
 165 void
 166 Key_engraver::read_event (Stream_event const *r)
 167 {
 168   SCM p = r->get_property ("pitch-alist");
 169   if (!scm_is_pair (p))
 170     return;
 171
 172   SCM accs = SCM_EOL;
 173
 174   SCM alist = scm_list_copy (p);
 175   SCM order = get_property ("keyAlterationOrder");
 176   for (SCM s = order;
 177        scm_is_pair (s) && scm_is_pair (alist); s = scm_cdr (s))
 178     {
 179       SCM head = scm_member (scm_car (s), alist);
 180
 181       if (scm_is_pair (head))
 182         {
 183           accs = scm_cons (scm_car (head), accs);
 184           alist = scm_delete_x (scm_car (head), alist);
 185         }
 186     }
 187
 188   if (scm_is_pair (alist))
 189     {
 190       bool warn = false;
 191       for (SCM s = alist; scm_is_pair (s); s = scm_cdr (s))
 192         if (ly_scm2rational (scm_cdar (s)))
 193           {
 194             warn = true;
 195             accs = scm_cons (scm_car (s), accs);
 196           }
 197
 198       if (warn)
 199         r->origin ()->warning ("No ordering for key signature alterations");
 200     }
 201
 202   context ()->set_property ("keySignature", scm_reverse (accs));
 203   context ()->set_property ("tonic",
 204                             r->get_property ("tonic"));
 205 }
 206
 207 void
 208 Key_engraver::initialize ()
 209 {
 210   context ()->set_property ("keySignature", SCM_EOL);
 211   context ()->set_property ("lastKeySignature", SCM_EOL);
 212
 213   Pitch p (0, 0, 0);
 214   context ()->set_property ("tonic", p.smobbed_copy ());
 215 }
 216
 217 ADD_ACKNOWLEDGER (Key_engraver, clef);
 218 ADD_ACKNOWLEDGER (Key_engraver, bar_line);
 219
 220 ADD_TRANSLATOR (Key_engraver,
 221                 /* doc */
 222                 "Engrave a key signature.",
 223
 224                 /* create */
 225                 "KeyCancellation "
 226                 "KeySignature ",
 227
 228                 /* read */
 229                 "createKeyOnClefChange "
 230                 "explicitKeySignatureVisibility "
 231                 "extraNatural "
 232                 "keyAlterationOrder "
 233                 "keySignature "
 234                 "lastKeySignature "
 235                 "printKeyCancellation ",
 236
 237                 /* write */
 238                 "keySignature "
 239                 "lastKeySignature "
 240                 "tonic "
 241                 );