lily/translator.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 "translator.hh"
  21
  22 #include "context-def.hh"
  23 #include "dispatcher.hh"
  24 #include "global-context.hh"
  25 #include "international.hh"
  26 #include "translator-group.hh"
  27 #include "warn.hh"
  28
  29 #include "translator.icc"
  30 #include "ly-smobs.icc"
  31
  32 Translator::~Translator ()
  33 {
  34 }
  35
  36 void
  37 Translator::init ()
  38 {
  39   self_scm_ = SCM_EOL;
  40   daddy_context_ = 0;
  41   smobify_self ();
  42 }
  43
  44 void
  45 Translator::process_music ()
  46 {
  47 }
  48
  49 void
  50 Translator::process_acknowledged ()
  51 {
  52 }
  53
  54 Translator::Translator ()
  55 {
  56   init ();
  57 }
  58
  59 Translator::Translator (Translator const &src)
  60 {
  61   (void) src;
  62   init ();
  63 }
  64
  65 Moment
  66 Translator::now_mom () const
  67 {
  68   return daddy_context_->now_mom ();
  69 }
  70
  71 Output_def *
  72 Translator::get_output_def () const
  73 {
  74   return daddy_context_->get_output_def ();
  75 }
  76
  77 Translator_group *
  78 Translator::get_daddy_translator () const
  79 {
  80   return daddy_context_->implementation ();
  81 }
  82
  83 void
  84 Translator::protect_event (SCM ev)
  85 {
  86   get_daddy_translator ()->protect_event (ev);
  87 }
  88
  89 SCM
  90 Translator::internal_get_property (SCM sym) const
  91 {
  92   return daddy_context_->internal_get_property (sym);
  93 }
  94
  95 void
  96 Translator::stop_translation_timestep ()
  97 {
  98 }
  99
 100 /*
 101   this function is called once each moment, before any user
 102   information enters the translators.  (i.e. no \property or event has
 103   been processed yet.)
 104 */
 105 void
 106 Translator::start_translation_timestep ()
 107 {
 108 }
 109
 110 void
 111 Translator::initialize ()
 112 {
 113 }
 114
 115 void
 116 Translator::finalize ()
 117 {
 118 }
 119
 120 void
 121 Translator::connect_to_context (Context *c)
 122 {
 123   for (translator_listener_record *r = get_listener_list (); r; r = r->next_)
 124     c->events_below ()->add_listener (r->get_listener_ (this, r->event_class_),
 125                                       r->event_class_);
 126 }
 127
 128 void
 129 Translator::disconnect_from_context (Context *c)
 130 {
 131   for (translator_listener_record *r = get_listener_list (); r; r = r->next_)
 132     c->events_below ()->remove_listener (r->get_listener_ (this, r->event_class_),
 133                                          r->event_class_);
 134 }
 135
 136 static SCM listened_event_class_table;
 137 void
 138 ensure_listened_hash ()
 139 {
 140   if (!listened_event_class_table)
 141     listened_event_class_table = scm_permanent_object (scm_c_make_hash_table (61));
 142 }
 143
 144
 145 LY_DEFINE (ly_get_listened_event_classes, "ly:get-listened-event-classes",
 146            0, 0, 0, (),
 147            "Return a list of all event classes that some translator listens"
 148            " to.")
 149 {
 150   ensure_listened_hash ();
 151   return ly_hash_table_keys (listened_event_class_table);
 152 }
 153
 154 LY_DEFINE (ly_is_listened_event_class, "ly:is-listened-event-class",
 155            1, 0, 0, (SCM sym),
 156            "Is @var{sym} a listened event class?")
 157 {
 158   ensure_listened_hash ();
 159   return scm_hashq_ref (listened_event_class_table, sym, SCM_BOOL_F);
 160 }
 161
 162 void
 163 add_listened_event_class (SCM sym)
 164 {
 165   ensure_listened_hash ();
 166   scm_hashq_set_x (listened_event_class_table, sym, SCM_BOOL_T);
 167 }
 168
 169
 170 /*
 171   internally called once, statically, for each translator
 172   listener. Connects the name of an event class with a procedure that
 173   fetches the corresponding listener.
 174
 175   The method should only be called from the macro
 176   IMPLEMENT_TRANSLATOR_LISTENER.
 177  */
 178 void
 179 Translator::add_translator_listener (translator_listener_record **listener_list,
 180                                      translator_listener_record *r,
 181                                      Listener (*get_listener) (void *, SCM),
 182                                      const char *ev_class)
 183 {
 184   /* ev_class is the C++ identifier name. Convert to scm symbol */
 185   string name = string (ev_class);
 186   name = replace_all (&name, '_', '-');
 187   name += "-event";
 188
 189   SCM class_sym = scm_str2symbol (name.c_str ());
 190
 191   add_listened_event_class (class_sym);
 192
 193   r->event_class_ = class_sym;
 194   r->get_listener_ = get_listener;
 195   r->next_ = *listener_list;
 196   *listener_list = r;
 197 }
 198
 199 /*
 200  Helps the individual static_translator_description methods of translators.
 201 */
 202 SCM
 203 Translator::static_translator_description (const char *grobs,
 204                                            const char *desc,
 205                                            translator_listener_record *listener_list,
 206                                            const char *read,
 207                                            const char *write) const
 208 {
 209   SCM static_properties = SCM_EOL;
 210
 211   static_properties = scm_acons (ly_symbol2scm ("grobs-created"),
 212                                  parse_symbol_list (grobs), static_properties);
 213
 214   static_properties = scm_acons (ly_symbol2scm ("description"),
 215                                  scm_from_locale_string (desc), static_properties);
 216
 217   SCM list = SCM_EOL;
 218   for (; listener_list; listener_list = listener_list->next_)
 219     list = scm_cons (listener_list->event_class_, list);
 220   static_properties = scm_acons (ly_symbol2scm ("events-accepted"),
 221                                  list, static_properties);
 222
 223   static_properties = scm_acons (ly_symbol2scm ("properties-read"),
 224                                  parse_symbol_list (read), static_properties);
 225
 226   static_properties = scm_acons (ly_symbol2scm ("properties-written"),
 227                                  parse_symbol_list (write), static_properties);
 228
 229   return static_properties;
 230 }
 231
 232 /*
 233   SMOBS
 234 */
 235 SCM
 236 Translator::mark_smob (SCM sm)
 237 {
 238   Translator *me = (Translator *) SCM_CELL_WORD_1 (sm);
 239   me->derived_mark ();
 240   return SCM_EOL;
 241 }
 242
 243 Global_context *
 244 Translator::get_global_context () const
 245 {
 246   return daddy_context_->get_global_context ();
 247 }
 248
 249 Context *
 250 Translator::get_score_context () const
 251 {
 252   return daddy_context_->get_score_context ();
 253 }
 254
 255 IMPLEMENT_SMOBS (Translator);
 256 IMPLEMENT_DEFAULT_EQUAL_P (Translator);
 257 IMPLEMENT_TYPE_P (Translator, "ly:translator?");
 258
 259 bool
 260 Translator::must_be_last () const
 261 {
 262   return false;
 263 }
 264
 265 void
 266 Translator::derived_mark () const
 267 {
 268 }
 269
 270 int
 271 Translator::print_smob (SCM s, SCM port, scm_print_state *)
 272 {
 273   Translator *me = (Translator *) SCM_CELL_WORD_1 (s);
 274   scm_puts ("#<Translator ", port);
 275   scm_puts (me->class_name (), port);
 276   scm_puts (" >", port);
 277   return 1;
 278 }
 279
 280 void
 281 add_acknowledger (Engraver_void_function_engraver_grob_info ptr,
 282                   char const *func_name,
 283                   vector<Acknowledge_information> *ack_array)
 284 {
 285   Acknowledge_information inf;
 286   inf.function_ = ptr;
 287
 288   string interface_name (func_name);
 289
 290   interface_name = replace_all (&interface_name, '_', '-');
 291   interface_name += "-interface";
 292
 293   /*
 294     this is only called during program init, so safe to use scm_gc_protect_object ()
 295   */
 296   inf.symbol_ = scm_gc_protect_object (ly_symbol2scm (interface_name.c_str ()));
 297   ack_array->push_back (inf);
 298 }
 299
 300 Engraver_void_function_engraver_grob_info
 301 generic_get_acknowledger (SCM sym, vector<Acknowledge_information> const *ack_array)
 302 {
 303   for (vsize i = 0; i < ack_array->size (); i++)
 304     {
 305       if (ack_array->at (i).symbol_ == sym)
 306         return ack_array->at (i).function_;
 307     }
 308   return 0;
 309 }
 310
 311
 312 Moment
 313 get_event_length (Stream_event *e)
 314 {
 315   Moment *m = unsmob_moment (e->get_property ("length"));
 316   if (m)
 317     return *m;
 318   else
 319     return Moment (0);
 320 }
 321
 322 Moment
 323 get_event_length (Stream_event *e, Moment now)
 324 {
 325   Moment len = get_event_length (e);
 326
 327   if (now.grace_part_)
 328     {
 329       len.grace_part_ = len.main_part_;
 330       len.main_part_ = Rational (0);
 331     }
 332   return len;
 333 }
 334
 335 /*
 336   Helper, used through ASSIGN_EVENT_ONCE to throw warnings for
 337   simultaneous events. The helper is only useful in listen_* methods
 338   of translators.
 339 */
 340 bool
 341 internal_event_assignment (Stream_event **old_ev, Stream_event *new_ev, const char *function)
 342 {
 343   if (*old_ev &&
 344       !to_boolean (scm_equal_p ((*old_ev)->self_scm (),
 345                                new_ev->self_scm ())))
 346     {
 347       /* extract event class from function name */
 348       string ev_class = function;
 349
 350       /* This assertion fails if EVENT_ASSIGNMENT was called outside a
 351          translator listener. Don't do that. */
 352       const char *prefix = "listen_";
 353       assert (0 == ev_class.find (prefix));
 354
 355       /* "listen_foo_bar" -> "foo-bar" */
 356       ev_class.erase (0, strlen (prefix));
 357       replace_all (&ev_class, '_', '-');
 358
 359       new_ev->origin ()->warning (_f ("Two simultaneous %s events, junking this one", ev_class.c_str ()));
 360       (*old_ev)->origin ()->warning (_f ("Previous %s event here", ev_class.c_str ()));
 361       return false;
 362     }
 363   else
 364     {
 365       *old_ev = new_ev;
 366       return true;
 367     }
 368 }
 369
 370 ADD_TRANSLATOR (Translator,
 371                 /* doc */
 372                 "Base class.  Not instantiated.",
 373
 374                 /* create */
 375                 "",
 376
 377                 /* read */
 378                 "",
 379
 380                 /* write */
 381                 ""
 382                 );