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--2007 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 < Rational (0))
  84                 {
  85                   *tail = scm_cons (scm_car (s), *tail);
  86                   tail = SCM_CDRLOC (*tail);
  87                 }
  88             }
  89
  90           if (scm_is_pair (restore))
  91             {
  92               cancellation_ = make_item ("KeyCancellation",
  93                                          key_event_
  94                                          ? key_event_->self_scm () : SCM_EOL);
  95
  96               cancellation_->set_property ("alteration-alist", restore);
  97               cancellation_->set_property ("c0-position",
  98                                            get_property ("middleCPosition"));
  99             }
 100         }
 101
 102       item_->set_property ("alteration-alist", key);
 103     }
 104
 105   if (!is_default)
 106     {
 107       SCM visibility = get_property ("explicitKeySignatureVisibility");
 108       item_->set_property ("break-visibility", visibility);
 109     }
 110 }
 111
 112 IMPLEMENT_TRANSLATOR_LISTENER (Key_engraver, key_change);
 113 void
 114 Key_engraver::listen_key_change (Stream_event *ev)
 115 {
 116   /* do this only once, just to be on the safe side.  */
 117   if (ASSIGN_EVENT_ONCE (key_event_, ev))
 118     read_event (key_event_);
 119 }
 120
 121 void
 122 Key_engraver::acknowledge_clef (Grob_info info)
 123 {
 124   (void)info;
 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   (void)info;
 134   if (scm_is_pair (get_property ("keySignature")))
 135     create_key (true);
 136 }
 137
 138 void
 139 Key_engraver::process_music ()
 140 {
 141   if (key_event_
 142       || get_property ("lastKeySignature") != get_property ("keySignature"))
 143     create_key (false);
 144 }
 145
 146 void
 147 Key_engraver::stop_translation_timestep ()
 148 {
 149   item_ = 0;
 150   context ()->set_property ("lastKeySignature", get_property ("keySignature"));
 151   cancellation_ = 0;
 152   key_event_ = 0;
 153 }
 154
 155 void
 156 Key_engraver::read_event (Stream_event const *r)
 157 {
 158   SCM p = r->get_property ("pitch-alist");
 159   if (!scm_is_pair (p))
 160     return;
 161
 162   SCM accs = SCM_EOL;
 163
 164   SCM alist = scm_list_copy (p);
 165   SCM order = get_property ("keyAlterationOrder");
 166   for (SCM s = order;
 167        scm_is_pair (s) && scm_is_pair (alist); s = scm_cdr (s))
 168     {
 169       SCM head = scm_member (scm_car (s), alist);
 170
 171       if (scm_is_pair (head))
 172         {
 173           accs = scm_cons (scm_car (head), accs);
 174           alist = scm_delete_x (scm_car (head), alist);
 175         }
 176     }
 177
 178   if (scm_is_pair (alist))
 179     {
 180       bool warn = false;
 181       for (SCM s = alist; scm_is_pair (s); s = scm_cdr (s))
 182         if (ly_scm2rational (scm_cdar (s)))
 183           {
 184             warn = true;
 185             accs = scm_cons (scm_car (s), accs);
 186           }
 187
 188       if (warn)
 189         r->origin ()->warning ("No ordering for key signature alterations");
 190     }
 191
 192   context ()->set_property ("keySignature", accs);
 193   context ()->set_property ("tonic",
 194                             r->get_property ("tonic"));
 195 }
 196
 197 void
 198 Key_engraver::initialize ()
 199 {
 200   context ()->set_property ("keySignature", SCM_EOL);
 201   context ()->set_property ("lastKeySignature", SCM_EOL);
 202
 203   Pitch p (0, 0, 0);
 204   context ()->set_property ("tonic", p.smobbed_copy ());
 205 }
 206
 207 ADD_ACKNOWLEDGER (Key_engraver, clef);
 208 ADD_ACKNOWLEDGER (Key_engraver, bar_line);
 209
 210 ADD_TRANSLATOR (Key_engraver,
 211                 /* doc */
 212                 "Engrave a key signature.",
 213
 214                 /* create */
 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                 );