lily/key-engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2011 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
  81       if ((to_boolean (get_property ("printKeyCancellation"))
  82            || key == SCM_EOL)
  83           && !scm_is_eq (last, key))
  84         {
  85           SCM restore = SCM_EOL;
  86           SCM *tail = &restore;
  87           for (SCM s = last; scm_is_pair (s); s = scm_cdr (s))
  88             {
  89               SCM new_alter_pair = scm_assoc (scm_caar (s), key);
  90               Rational old_alter = robust_scm2rational (scm_cdar (s), 0);
  91               if (new_alter_pair == SCM_BOOL_F
  92                   || ((ly_scm2rational (scm_cdr (new_alter_pair)) - old_alter) * old_alter
  93                       < Rational (0)))
  94                 {
  95                   *tail = scm_cons (scm_car (s), *tail);
  96                   tail = SCM_CDRLOC (*tail);
  97                 }
  98             }
  99
 100           if (scm_is_pair (restore))
 101             {
 102               cancellation_ = make_item ("KeyCancellation",
 103                                          key_event_
 104                                          ? key_event_->self_scm () : SCM_EOL);
 105
 106               cancellation_->set_property ("alteration-alist", scm_reverse (restore));
 107               cancellation_->set_property ("c0-position",
 108                                            get_property ("middleCPosition"));
 109             }
 110         }
 111
 112       item_->set_property ("alteration-alist", scm_reverse (key));
 113     }
 114
 115   if (!is_default)
 116     {
 117       SCM visibility = get_property ("explicitKeySignatureVisibility");
 118       item_->set_property ("break-visibility", visibility);
 119     }
 120 }
 121
 122 IMPLEMENT_TRANSLATOR_LISTENER (Key_engraver, key_change);
 123 void
 124 Key_engraver::listen_key_change (Stream_event *ev)
 125 {
 126   /* do this only once, just to be on the safe side.  */
 127   if (ASSIGN_EVENT_ONCE (key_event_, ev))
 128     read_event (key_event_);
 129 }
 130
 131 void
 132 Key_engraver::acknowledge_clef (Grob_info /* info */)
 133 {
 134   SCM c = get_property ("createKeyOnClefChange");
 135   if (to_boolean (c))
 136     create_key (false);
 137 }
 138
 139 void
 140 Key_engraver::acknowledge_bar_line (Grob_info /* info */)
 141 {
 142   if (scm_is_pair (get_property ("keySignature")))
 143     create_key (true);
 144 }
 145
 146 void
 147 Key_engraver::process_music ()
 148 {
 149   if (key_event_
 150       || get_property ("lastKeySignature") != get_property ("keySignature"))
 151     create_key (false);
 152 }
 153
 154 void
 155 Key_engraver::stop_translation_timestep ()
 156 {
 157   item_ = 0;
 158   context ()->set_property ("lastKeySignature", get_property ("keySignature"));
 159   cancellation_ = 0;
 160   key_event_ = 0;
 161 }
 162
 163 void
 164 Key_engraver::read_event (Stream_event const *r)
 165 {
 166   SCM p = r->get_property ("pitch-alist");
 167   if (!scm_is_pair (p))
 168     return;
 169
 170   SCM accs = SCM_EOL;
 171
 172   SCM alist = scm_list_copy (p);
 173   SCM order = get_property ("keyAlterationOrder");
 174   for (SCM s = order;
 175        scm_is_pair (s) && scm_is_pair (alist); s = scm_cdr (s))
 176     {
 177       SCM head = scm_member (scm_car (s), alist);
 178
 179       if (scm_is_pair (head))
 180         {
 181           accs = scm_cons (scm_car (head), accs);
 182           alist = scm_delete_x (scm_car (head), alist);
 183         }
 184     }
 185
 186   if (scm_is_pair (alist))
 187     {
 188       bool warn = false;
 189       for (SCM s = alist; scm_is_pair (s); s = scm_cdr (s))
 190         if (ly_scm2rational (scm_cdar (s)))
 191           {
 192             warn = true;
 193             accs = scm_cons (scm_car (s), accs);
 194           }
 195
 196       if (warn)
 197         r->origin ()->warning ("Incomplete keyAlterationOrder for key signature");
 198     }
 199
 200   context ()->set_property ("keySignature", scm_reverse (accs));
 201   context ()->set_property ("tonic",
 202                             r->get_property ("tonic"));
 203 }
 204
 205 void
 206 Key_engraver::initialize ()
 207 {
 208   context ()->set_property ("keySignature", SCM_EOL);
 209   context ()->set_property ("lastKeySignature", SCM_EOL);
 210
 211   Pitch p (0, 0, 0);
 212   context ()->set_property ("tonic", p.smobbed_copy ());
 213 }
 214
 215 ADD_ACKNOWLEDGER (Key_engraver, clef);
 216 ADD_ACKNOWLEDGER (Key_engraver, bar_line);
 217
 218 ADD_TRANSLATOR (Key_engraver,
 219                 /* doc */
 220                 "Engrave a key signature.",
 221
 222                 /* create */
 223                 "KeyCancellation "
 224                 "KeySignature ",
 225
 226                 /* read */
 227                 "createKeyOnClefChange "
 228                 "explicitKeySignatureVisibility "
 229                 "extraNatural "
 230                 "keyAlterationOrder "
 231                 "keySignature "
 232                 "lastKeySignature "
 233                 "printKeyCancellation ",
 234
 235                 /* write */
 236                 "keySignature "
 237                 "lastKeySignature "
 238                 "tonic "
 239                 );