lily/key-engraver.cc

   1 /*
   2   key-engraver.cc -- implement Key_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "bar-line.hh"
  10 #include "clef.hh"
  11 #include "context.hh"
  12 #include "engraver.hh"
  13 #include "item.hh"
  14 #include "pitch.hh"
  15 #include "protected-scm.hh"
  16 #include "staff-symbol-referencer.hh"
  17 #include "stream-event.hh"
  18
  19 #include "translator.icc"
  20
  21 class Key_engraver : public Engraver
  22 {
  23   void create_key (bool);
  24   void read_event (Stream_event const *r);
  25
  26   Stream_event *key_event_;
  27   Item *item_;
  28   Item *cancellation_;
  29 public:
  30   TRANSLATOR_DECLARATIONS (Key_engraver);
  31
  32 protected:
  33   virtual void initialize ();
  34   virtual void finalize ();
  35   void stop_translation_timestep ();
  36   void process_music ();
  37
  38   DECLARE_TRANSLATOR_LISTENER (key_change);
  39   DECLARE_ACKNOWLEDGER (clef);
  40   DECLARE_ACKNOWLEDGER (bar_line);
  41 };
  42
  43 void
  44 Key_engraver::finalize ()
  45 {
  46 }
  47
  48 Key_engraver::Key_engraver ()
  49 {
  50   key_event_ = 0;
  51   item_ = 0;
  52   cancellation_ = 0;
  53 }
  54
  55
  56 void
  57 Key_engraver::create_key (bool is_default)
  58 {
  59   if (!item_)
  60     {
  61       item_ = make_item ("KeySignature",
  62                          key_event_ ? key_event_->self_scm () : SCM_EOL);
  63
  64       item_->set_property ("c0-position",
  65                            get_property ("middleCPosition"));
  66
  67       SCM last = get_property ("lastKeySignature");
  68       SCM key = get_property ("keySignature");
  69       bool extranatural = to_boolean (get_property ("extraNatural"));
  70
  71       if ((to_boolean (get_property ("printKeyCancellation"))
  72            || key == SCM_EOL)
  73           && !scm_is_eq (last, key))
  74         {
  75           SCM restore = SCM_EOL;
  76           SCM *tail = &restore;
  77           for (SCM s = last; scm_is_pair (s); s = scm_cdr (s))
  78             {
  79               SCM new_alter_pair = scm_assoc (scm_caar (s), key);
  80               Rational old_alter = robust_scm2rational (scm_cdar (s), 0);
  81               if (new_alter_pair == SCM_BOOL_F
  82                   || (extranatural
  83                       && (ly_scm2rational (scm_cdr (new_alter_pair)) - old_alter)*old_alter
  84                           < Rational (0)))
  85                 {
  86                   *tail = scm_cons (scm_car (s), *tail);
  87                   tail = SCM_CDRLOC (*tail);
  88                 }
  89             }
  90
  91           if (scm_is_pair (restore))
  92             {
  93               cancellation_ = make_item ("KeyCancellation",
  94                                          key_event_
  95                                          ? key_event_->self_scm () : SCM_EOL);
  96
  97               cancellation_->set_property ("alteration-alist", scm_reverse (restore));
  98               cancellation_->set_property ("c0-position",
  99                                            get_property ("middleCPosition"));
 100             }
 101         }
 102
 103       item_->set_property ("alteration-alist", scm_reverse (key));
 104     }
 105
 106   if (!is_default)
 107     {
 108       SCM visibility = get_property ("explicitKeySignatureVisibility");
 109       item_->set_property ("break-visibility", visibility);
 110     }
 111 }
 112
 113 IMPLEMENT_TRANSLATOR_LISTENER (Key_engraver, key_change);
 114 void
 115 Key_engraver::listen_key_change (Stream_event *ev)
 116 {
 117   /* do this only once, just to be on the safe side.  */
 118   if (ASSIGN_EVENT_ONCE (key_event_, ev))
 119     read_event (key_event_);
 120 }
 121
 122 void
 123 Key_engraver::acknowledge_clef (Grob_info /* info */)
 124 {
 125   SCM c = get_property ("createKeyOnClefChange");
 126   if (to_boolean (c))
 127     create_key (false);
 128 }
 129
 130 void
 131 Key_engraver::acknowledge_bar_line (Grob_info /* info */)
 132 {
 133   if (scm_is_pair (get_property ("keySignature")))
 134     create_key (true);
 135 }
 136
 137 void
 138 Key_engraver::process_music ()
 139 {
 140   if (key_event_
 141       || get_property ("lastKeySignature") != get_property ("keySignature"))
 142     create_key (false);
 143 }
 144
 145 void
 146 Key_engraver::stop_translation_timestep ()
 147 {
 148   item_ = 0;
 149   context ()->set_property ("lastKeySignature", get_property ("keySignature"));
 150   cancellation_ = 0;
 151   key_event_ = 0;
 152 }
 153
 154 void
 155 Key_engraver::read_event (Stream_event const *r)
 156 {
 157   SCM p = r->get_property ("pitch-alist");
 158   if (!scm_is_pair (p))
 159     return;
 160
 161   SCM accs = SCM_EOL;
 162
 163   SCM alist = scm_list_copy (p);
 164   SCM order = get_property ("keyAlterationOrder");
 165   for (SCM s = order;
 166        scm_is_pair (s) && scm_is_pair (alist); s = scm_cdr (s))
 167     {
 168       SCM head = scm_member (scm_car (s), alist);
 169
 170       if (scm_is_pair (head))
 171         {
 172           accs = scm_cons (scm_car (head), accs);
 173           alist = scm_delete_x (scm_car (head), alist);
 174         }
 175     }
 176
 177   if (scm_is_pair (alist))
 178     {
 179       bool warn = false;
 180       for (SCM s = alist; scm_is_pair (s); s = scm_cdr (s))
 181         if (ly_scm2rational (scm_cdar (s)))
 182           {
 183             warn = true;
 184             accs = scm_cons (scm_car (s), accs);
 185           }
 186
 187       if (warn)
 188         r->origin ()->warning ("No ordering for key signature alterations");
 189     }
 190
 191   context ()->set_property ("keySignature", scm_reverse (accs));
 192   context ()->set_property ("tonic",
 193                             r->get_property ("tonic"));
 194 }
 195
 196 void
 197 Key_engraver::initialize ()
 198 {
 199   context ()->set_property ("keySignature", SCM_EOL);
 200   context ()->set_property ("lastKeySignature", SCM_EOL);
 201
 202   Pitch p (0, 0, 0);
 203   context ()->set_property ("tonic", p.smobbed_copy ());
 204 }
 205
 206 ADD_ACKNOWLEDGER (Key_engraver, clef);
 207 ADD_ACKNOWLEDGER (Key_engraver, bar_line);
 208
 209 ADD_TRANSLATOR (Key_engraver,
 210                 /* doc */
 211                 "Engrave a key signature.",
 212
 213                 /* create */
 214                 "KeyCancellation "
 215                 "KeySignature ",
 216
 217                 /* read */
 218                 "createKeyOnClefChange "
 219                 "explicitKeySignatureVisibility "
 220                 "extraNatural "
 221                 "keyAlterationOrder "
 222                 "keySignature "
 223                 "lastKeySignature "
 224                 "printKeyCancellation ",
 225
 226                 /* write */
 227                 "keySignature "
 228                 "lastKeySignature "
 229                 "tonic "
 230                 );