lily/translator.cc

   1 /*
   2   translator.cc -- implement Translator
   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 "translator.hh"
  10
  11 #include "context-def.hh"
  12 #include "dispatcher.hh"
  13 #include "global-context.hh"
  14 #include "international.hh"
  15 #include "translator-group.hh"
  16 #include "warn.hh"
  17
  18 #include "translator.icc"
  19 #include "ly-smobs.icc"
  20
  21 Translator::~Translator ()
  22 {
  23 }
  24
  25 void
  26 Translator::init ()
  27 {
  28   must_be_last_ = false;
  29   self_scm_ = SCM_EOL;
  30   daddy_context_ = 0;
  31   smobify_self ();
  32 }
  33
  34 void
  35 Translator::process_music ()
  36 {
  37 }
  38
  39 void
  40 Translator::process_acknowledged ()
  41 {
  42 }
  43
  44 Translator::Translator ()
  45 {
  46   init ();
  47 }
  48
  49 Translator::Translator (Translator const &src)
  50 {
  51   init ();
  52   must_be_last_ = src.must_be_last_;
  53 }
  54
  55 Moment
  56 Translator::now_mom () const
  57 {
  58   return daddy_context_->now_mom ();
  59 }
  60
  61 Output_def *
  62 Translator::get_output_def () const
  63 {
  64   return daddy_context_->get_output_def ();
  65 }
  66
  67 Translator_group *
  68 Translator::get_daddy_translator () const
  69 {
  70   return daddy_context_->implementation ();
  71 }
  72
  73 void
  74 Translator::protect_event (SCM ev)
  75 {
  76   get_daddy_translator ()->protect_event (ev);
  77 }
  78
  79 SCM
  80 Translator::internal_get_property (SCM sym) const
  81 {
  82   return daddy_context_->internal_get_property (sym);
  83 }
  84
  85 void
  86 Translator::stop_translation_timestep ()
  87 {
  88 }
  89
  90 /*
  91   this function is called once each moment, before any user
  92   information enters the translators.  (i.e. no \property or event has
  93   been processed yet.)
  94 */
  95 void
  96 Translator::start_translation_timestep ()
  97 {
  98 }
  99
 100 void
 101 Translator::initialize ()
 102 {
 103 }
 104
 105 void
 106 Translator::finalize ()
 107 {
 108 }
 109
 110 void
 111 Translator::connect_to_context (Context *c)
 112 {
 113   for (translator_listener_record *r = get_listener_list (); r; r=r->next_)
 114     c->events_below ()->add_listener (r->get_listener_ (this), r->event_class_);
 115 }
 116
 117 void
 118 Translator::disconnect_from_context (Context *c)
 119 {
 120   for (translator_listener_record *r = get_listener_list (); r; r=r->next_)
 121     c->events_below ()->remove_listener (r->get_listener_ (this), r->event_class_);
 122 }
 123
 124 static SCM listened_event_class_table;
 125 void
 126 ensure_listened_hash ()
 127 {
 128   if (!listened_event_class_table)
 129     listened_event_class_table = scm_permanent_object (scm_c_make_hash_table (61));
 130 }
 131
 132
 133 LY_DEFINE (ly_get_listened_event_classes, "ly:get-listened-event-classes",
 134            0, 0, 0, (),
 135            "Return a list of all event classes that some translator listens"
 136            " to.")
 137 {
 138   ensure_listened_hash ();
 139   return ly_hash_table_keys (listened_event_class_table);
 140 }
 141
 142 LY_DEFINE (ly_is_listened_event_class, "ly:is-listened-event-class",
 143            1, 0, 0, (SCM sym),
 144            "Is @var{sym} a listened event class?")
 145 {
 146   ensure_listened_hash ();
 147   return scm_hashq_ref (listened_event_class_table, sym, SCM_BOOL_F);
 148 }
 149
 150 void
 151 add_listened_event_class (SCM sym)
 152 {
 153   ensure_listened_hash ();
 154   scm_hashq_set_x (listened_event_class_table, sym, SCM_BOOL_T);
 155 }
 156
 157
 158 /*
 159   internally called once, statically, for each translator
 160   listener. Connects the name of an event class with a procedure that
 161   fetches the corresponding listener.
 162
 163   The method should only be called from the macro
 164   IMPLEMENT_TRANSLATOR_LISTENER.
 165  */
 166 void
 167 Translator::add_translator_listener (translator_listener_record **listener_list,
 168                                      translator_listener_record *r,
 169                                      Listener (*get_listener) (void *),
 170                                      const char *ev_class)
 171 {
 172   /* ev_class is the C++ identifier name. Convert to scm symbol */
 173   string name = string (ev_class);
 174   name = replace_all (&name, '_', '-');
 175   name += "-event";
 176
 177   SCM class_sym = scm_str2symbol (name.c_str ());
 178
 179   add_listened_event_class (class_sym);
 180
 181   r->event_class_ = class_sym;
 182   r->get_listener_ = get_listener;
 183   r->next_ = *listener_list;
 184   *listener_list = r;
 185 }
 186
 187 /*
 188  Helps the individual static_translator_description methods of translators.
 189 */
 190 SCM
 191 Translator::static_translator_description (const char *grobs,
 192                                            const char *desc,
 193                                            translator_listener_record *listener_list,
 194                                            const char *read,
 195                                            const char *write) const
 196 {
 197   SCM static_properties = SCM_EOL;
 198
 199   static_properties = scm_acons (ly_symbol2scm ("grobs-created"),
 200                                  parse_symbol_list (grobs), static_properties);
 201
 202   static_properties = scm_acons (ly_symbol2scm ("description"),
 203                                  scm_from_locale_string (desc), static_properties);
 204
 205   SCM list = SCM_EOL;
 206   for (; listener_list; listener_list = listener_list->next_)
 207     list = scm_cons (listener_list->event_class_, list);
 208   static_properties = scm_acons (ly_symbol2scm ("events-accepted"),
 209                                  list, static_properties);
 210
 211   static_properties = scm_acons (ly_symbol2scm ("properties-read"),
 212                                  parse_symbol_list (read), static_properties);
 213
 214   static_properties = scm_acons (ly_symbol2scm ("properties-written"),
 215                                  parse_symbol_list (write), static_properties);
 216
 217   return static_properties;
 218 }
 219
 220 /*
 221   SMOBS
 222 */
 223 SCM
 224 Translator::mark_smob (SCM sm)
 225 {
 226   Translator *me = (Translator *) SCM_CELL_WORD_1 (sm);
 227   me->derived_mark ();
 228   return SCM_EOL;
 229 }
 230
 231 Global_context *
 232 Translator::get_global_context () const
 233 {
 234   return daddy_context_->get_global_context ();
 235 }
 236
 237 Context *
 238 Translator::get_score_context () const
 239 {
 240   return daddy_context_->get_score_context ();
 241 }
 242
 243 IMPLEMENT_SMOBS (Translator);
 244 IMPLEMENT_DEFAULT_EQUAL_P (Translator);
 245 IMPLEMENT_TYPE_P (Translator, "ly:translator?");
 246
 247 bool
 248 Translator::must_be_last () const
 249 {
 250   return must_be_last_;
 251 }
 252
 253 void
 254 Translator::derived_mark () const
 255 {
 256 }
 257
 258 int
 259 Translator::print_smob (SCM s, SCM port, scm_print_state *)
 260 {
 261   Translator *me = (Translator *) SCM_CELL_WORD_1 (s);
 262   scm_puts ("#<Translator ", port);
 263   scm_puts (me->class_name (), port);
 264   scm_puts (" >", port);
 265   return 1;
 266 }
 267
 268 void
 269 add_acknowledger (Engraver_void_function_engraver_grob_info ptr,
 270                   char const *func_name,
 271                   vector<Acknowledge_information> *ack_array)
 272 {
 273   Acknowledge_information inf;
 274   inf.function_ = ptr;
 275
 276   string interface_name (func_name);
 277
 278   interface_name = replace_all (&interface_name, '_', '-');
 279   interface_name += "-interface";
 280
 281   /*
 282     this is only called during program init, so safe to use scm_gc_protect_object ()
 283   */
 284   inf.symbol_ = scm_gc_protect_object (ly_symbol2scm (interface_name.c_str ()));
 285   ack_array->push_back (inf);
 286 }
 287
 288 Engraver_void_function_engraver_grob_info
 289 generic_get_acknowledger (SCM sym, vector<Acknowledge_information> const *ack_array)
 290 {
 291   for (vsize i = 0; i < ack_array->size (); i++)
 292     {
 293       if (ack_array->at (i).symbol_ == sym)
 294         return ack_array->at (i).function_;
 295     }
 296   return 0;
 297 }
 298
 299
 300 Moment
 301 get_event_length (Stream_event *e)
 302 {
 303   Moment *m = unsmob_moment (e->get_property ("length"));
 304   if (m)
 305     return *m;
 306   else
 307     return Moment (0);
 308 }
 309
 310 Moment
 311 get_event_length (Stream_event *e, Moment now)
 312 {
 313   Moment len = get_event_length (e);
 314
 315   if (now.grace_part_)
 316     {
 317       len.grace_part_ = len.main_part_;
 318       len.main_part_ = Rational (0);
 319     }
 320   return len;
 321 }
 322
 323 /*
 324   Helper, used through ASSIGN_EVENT_ONCE to throw warnings for
 325   simultaneous events. The helper is only useful in listen_* methods
 326   of translators.
 327 */
 328 bool
 329 internal_event_assignment (Stream_event **old_ev, Stream_event *new_ev, const char *function)
 330 {
 331   if (*old_ev &&
 332       !to_boolean (scm_equal_p ((*old_ev)->self_scm (),
 333                                new_ev->self_scm ())))
 334     {
 335       /* extract event class from function name */
 336       string ev_class = function;
 337
 338       /* This assertion fails if EVENT_ASSIGNMENT was called outside a
 339          translator listener. Don't do that. */
 340       const char *prefix = "listen_";
 341       assert (0 == ev_class.find (prefix));
 342
 343       /* "listen_foo_bar" -> "foo-bar" */
 344       ev_class.erase (0, strlen (prefix));
 345       replace_all (&ev_class, '_', '-');
 346
 347       new_ev->origin ()->warning (_f ("Two simultaneous %s events, junking this one", ev_class.c_str ()));
 348       (*old_ev)->origin ()->warning (_f ("Previous %s event here", ev_class.c_str ()));
 349       return false;
 350     }
 351   else
 352     {
 353       *old_ev = new_ev;
 354       return true;
 355     }
 356 }
 357
 358 ADD_TRANSLATOR (Translator,
 359                 /* doc */
 360                 "Base class.  Not instantiated.",
 361
 362                 /* create */
 363                 "",
 364
 365                 /* read */
 366                 "",
 367
 368                 /* write */
 369                 ""
 370                 );