lily/scheme-engraver.cc

   1 /*
   2   scheme-engraver.cc -- implement Scheme_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   Copyright (c) 2009--2015 Han-Wen Nienhuys <hanwen@lilypond.org>
   7
   8   LilyPond is free software: you can redistribute it and/or modify
   9   it under the terms of the GNU General Public License as published by
  10   the Free Software Foundation, either version 3 of the License, or
  11   (at your option) any later version.
  12
  13   LilyPond is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16   GNU General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "scheme-engraver.hh"
  23
  24 #include "grob.hh"
  25
  26 #include "translator.icc"
  27
  28 Scheme_engraver::Scheme_engraver (SCM definition)
  29 {
  30   stop_translation_timestep_function_ = SCM_EOL;
  31   start_translation_timestep_function_ = SCM_EOL;
  32   process_music_function_ = SCM_EOL;
  33   process_acknowledged_function_ = SCM_EOL;
  34   initialize_function_ = SCM_EOL;
  35   finalize_function_ = SCM_EOL;
  36
  37   interface_acknowledger_hash_ = SCM_EOL;
  38   interface_end_acknowledger_hash_ = SCM_EOL;
  39
  40   must_be_last_ = false;
  41   per_instance_listeners_ = SCM_EOL;
  42
  43   init_from_scheme (definition);
  44 }
  45
  46 Scheme_engraver::~Scheme_engraver ()
  47 {
  48 }
  49
  50 // Extracts the value if callable, if not return #f.
  51 static SCM
  52 callable (SCM symbol, SCM defn)
  53 {
  54   SCM val = ly_assoc_get (symbol, defn, SCM_BOOL_F);
  55   return ly_is_procedure (val) ? val : SCM_BOOL_F;
  56 }
  57
  58 bool
  59 Scheme_engraver::must_be_last () const
  60 {
  61   return must_be_last_;
  62 }
  63
  64 void
  65 Scheme_engraver::init_from_scheme (SCM definition)
  66 {
  67   start_translation_timestep_function_ = callable (ly_symbol2scm ("start-translation-timestep"),
  68                                                    definition);
  69   stop_translation_timestep_function_ = callable (ly_symbol2scm ("stop-translation-timestep"),
  70                                                   definition);
  71   process_music_function_ = callable (ly_symbol2scm ("process-music"), definition);
  72   process_acknowledged_function_ = callable (ly_symbol2scm ("process-acknowledged"),
  73                                              definition);
  74   initialize_function_ = callable (ly_symbol2scm ("initialize"), definition);
  75   finalize_function_ = callable (ly_symbol2scm ("finalize"), definition);
  76
  77   SCM listeners = ly_assoc_get (ly_symbol2scm ("listeners"), definition, SCM_EOL);
  78
  79   per_instance_listeners_ = SCM_EOL;
  80
  81   must_be_last_ = to_boolean (ly_assoc_get (ly_symbol2scm ("must-be-last"),
  82                                             definition,
  83                                             SCM_BOOL_F));
  84
  85   for (SCM p = listeners; scm_is_pair (p); p = scm_cdr (p))
  86     {
  87       SCM event_class = scm_caar (p);
  88       SCM proc = scm_cdar (p);
  89
  90       if (!(ly_is_procedure (proc) && ly_is_symbol (event_class)))
  91         continue;
  92
  93       // We should check the arity of the function?
  94
  95       // Record for later lookup.
  96       per_instance_listeners_ = scm_acons (event_class, proc, per_instance_listeners_);
  97     }
  98
  99   init_acknowledgers (ly_assoc_get (ly_symbol2scm ("acknowledgers"),
 100                                     definition, SCM_EOL),
 101                       &interface_acknowledger_hash_);
 102
 103   init_acknowledgers (ly_assoc_get (ly_symbol2scm ("end-acknowledgers"),
 104                                     definition, SCM_EOL),
 105                       &interface_end_acknowledger_hash_);
 106
 107   // TODO: hook up description, props read/written, grobs created
 108   // etc. to provide automatic documentation.
 109 }
 110
 111 void
 112 Scheme_engraver::init_acknowledgers (SCM alist,
 113                                      SCM *hash)
 114 {
 115   *hash = scm_c_make_hash_table (7);
 116   for (SCM p = alist; scm_is_pair (p); p = scm_cdr (p))
 117     {
 118       SCM iface = scm_caar (p);
 119       SCM proc = scm_cdar (p);
 120
 121       if (!(ly_is_procedure (proc) && ly_is_symbol (iface)))
 122         continue;
 123
 124       scm_hashq_set_x (*hash, iface, proc);
 125     }
 126 }
 127
 128 // This is the easy way to do it, at the cost of too many invocations
 129 // of Scheme_engraver::acknowledge_grob.  The clever dispatching of
 130 // acknowledgers is hardwired to have 1 method per engraver per
 131 // grob-type, which doesn't work for this case.
 132 void
 133 Scheme_engraver::acknowledge_grob (Grob_info info)
 134 {
 135   acknowledge_grob_by_hash (info, interface_acknowledger_hash_);
 136 }
 137
 138 void
 139 Scheme_engraver::acknowledge_end_grob (Grob_info info)
 140 {
 141   acknowledge_grob_by_hash (info, interface_end_acknowledger_hash_);
 142 }
 143
 144 void
 145 Scheme_engraver::acknowledge_grob_by_hash (Grob_info info,
 146                                            SCM iface_function_hash)
 147 {
 148   SCM meta = info.grob ()->get_property ("meta");
 149   SCM ifaces = scm_cdr (scm_assoc (ly_symbol2scm ("interfaces"), meta));
 150   for (SCM s = ifaces; scm_is_pair (s); s = scm_cdr (s))
 151     {
 152       SCM func = scm_hashq_ref (iface_function_hash,
 153                                 scm_car (s), SCM_BOOL_F);
 154
 155       if (ly_is_procedure (func))
 156         scm_call_3 (func, self_scm (), info.grob ()->self_scm (),
 157                     info.origin_translator ()->self_scm ());
 158     }
 159 }
 160
 161 SCM
 162 Scheme_engraver::get_listener_list () const
 163 {
 164   return per_instance_listeners_;
 165 }
 166
 167 #define DISPATCH(what)                                  \
 168   void                                                  \
 169   Scheme_engraver::what ()                              \
 170   {                                                     \
 171     if (what ## _function_ != SCM_BOOL_F)               \
 172       scm_call_1 (what ## _function_, self_scm ());     \
 173   }
 174
 175 DISPATCH (start_translation_timestep);
 176 DISPATCH (stop_translation_timestep);
 177 DISPATCH (initialize);
 178 DISPATCH (finalize);
 179 DISPATCH (process_music);
 180 DISPATCH (process_acknowledged);
 181
 182 void
 183 Scheme_engraver::derived_mark () const
 184 {
 185   scm_gc_mark (start_translation_timestep_function_);
 186   scm_gc_mark (stop_translation_timestep_function_);
 187   scm_gc_mark (initialize_function_);
 188   scm_gc_mark (finalize_function_);
 189   scm_gc_mark (process_music_function_);
 190   scm_gc_mark (process_acknowledged_function_);
 191   scm_gc_mark (per_instance_listeners_);
 192   scm_gc_mark (interface_acknowledger_hash_);
 193   scm_gc_mark (interface_end_acknowledger_hash_);
 194 }
 195
 196 ADD_ACKNOWLEDGER (Scheme_engraver, grob);
 197 ADD_END_ACKNOWLEDGER (Scheme_engraver, grob);
 198
 199 ADD_TRANSLATOR_FAMILY (Scheme_engraver);