lily/engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2011 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 "engraver.hh"
  21
  22 #include "context.hh"
  23 #include "international.hh"
  24 #include "music.hh"
  25 #include "paper-column.hh"
  26 #include "score-engraver.hh"
  27 #include "spanner.hh"
  28 #include "stream-event.hh"
  29 #include "warn.hh"
  30
  31 Engraver_group *
  32 Engraver::get_daddy_engraver () const
  33 {
  34   return dynamic_cast<Engraver_group *> (get_daddy_translator ());
  35 }
  36
  37 void
  38 Engraver::announce_grob (Grob_info inf)
  39 {
  40   get_daddy_engraver ()->announce_grob (inf);
  41 }
  42
  43 void
  44 Engraver::announce_end_grob (Grob_info inf)
  45 {
  46   get_daddy_engraver ()->announce_grob (inf);
  47 }
  48
  49 /*
  50   CAUSE is the object (typically a Stream_event object)  that
  51   was the reason for making E.
  52 */
  53 void
  54 Engraver::announce_grob (Grob *e, SCM cause)
  55 {
  56   /* TODO: Remove Music code when it's no longer needed */
  57   if (Music *m = unsmob_music (cause))
  58     {
  59       cause = m->to_event ()->unprotect ();
  60     }
  61   if (unsmob_stream_event (cause) || unsmob_grob (cause))
  62     e->set_property ("cause", cause);
  63
  64   Grob_info i (this, e);
  65
  66   Engraver_group *g = get_daddy_engraver ();
  67   if (g)
  68     g->announce_grob (i);
  69 }
  70
  71
  72 /*
  73   CAUSE is the object (typically a grob or stream-event object) that
  74   was the reason for ending E.  */
  75 void
  76 Engraver::announce_end_grob (Grob *e, SCM cause)
  77 {
  78   /* TODO: Remove Music code when it's no longer needed */
  79   if (Music *m = unsmob_music (cause))
  80     {
  81       cause = m->to_event ()->unprotect ();
  82     }
  83   if (e->get_property ("cause") == SCM_EOL
  84       && (unsmob_stream_event (cause) || unsmob_grob (cause)))
  85     e->set_property ("cause", cause);
  86
  87   Grob_info i (this, e);
  88
  89   i.start_end_ = STOP;
  90   Engraver_group *g = get_daddy_engraver ();
  91   if (g)
  92     g->announce_grob (i);
  93 }
  94
  95
  96 Engraver::Engraver ()
  97 {
  98 }
  99
 100 #ifndef NDEBUG
 101 static SCM creation_callback = SCM_EOL;
 102 LY_DEFINE (ly_set_grob_creation_callback, "ly:set-grob-creation-callback",
 103            1, 0, 0, (SCM cb),
 104            "Specify a procedure that will be called every time a new grob"
 105            " is created.  The callback will receive as arguments the grob"
 106            " that was created, the name of the C++ source file that caused"
 107            " the grob to be created, and the corresponding line number in"
 108            " the C++ source file.")
 109 {
 110   LY_ASSERT_TYPE (ly_is_procedure, cb, 1);
 111
 112   creation_callback = cb;
 113
 114   return SCM_UNSPECIFIED;
 115 }
 116 #endif
 117
 118 Grob *
 119 Engraver::internal_make_grob (SCM symbol,
 120                               SCM cause,
 121                               char const * /* name */,
 122                               char const *file,
 123                               int line,
 124                               char const *fun)
 125 {
 126 #ifdef NDEBUG
 127   (void)file;
 128   (void)line;
 129   (void)fun;
 130 #endif
 131
 132   SCM props = updated_grob_properties (context (), symbol);
 133
 134   Grob *grob = 0;
 135
 136   SCM handle = scm_sloppy_assq (ly_symbol2scm ("meta"), props);
 137   SCM klass = scm_cdr (scm_sloppy_assq (ly_symbol2scm ("class"), scm_cdr (handle)));
 138
 139   if (klass == ly_symbol2scm ("Item"))
 140     grob = new Item (props);
 141   else if (klass == ly_symbol2scm ("Spanner"))
 142     grob = new Spanner (props);
 143   else if (klass == ly_symbol2scm ("Paper_column"))
 144     grob = new Paper_column (props);
 145
 146   assert (grob);
 147   announce_grob (grob, cause);
 148
 149 #ifndef NDEBUG
 150   if (ly_is_procedure (creation_callback))
 151     scm_apply_0 (creation_callback,
 152                  scm_list_n (grob->self_scm (), scm_from_locale_string (file),
 153                              scm_from_int (line), scm_from_locale_string (fun), SCM_UNDEFINED));
 154 #endif
 155
 156   return grob;
 157 }
 158
 159 Item *
 160 Engraver::internal_make_item (SCM x, SCM cause,
 161                               char const *name,
 162                               char const *file, int line, char const *fun)
 163 {
 164   Item *it = dynamic_cast<Item *> (internal_make_grob (x, cause, name, file, line, fun));
 165   assert (it);
 166   return it;
 167 }
 168
 169 Paper_column *
 170 Engraver::internal_make_column (SCM x, char const *name,
 171                                 char const *file, int line, char const *fun)
 172 {
 173   return dynamic_cast<Paper_column *> (internal_make_grob (x, SCM_EOL, name, file, line, fun));
 174 }
 175
 176 Spanner *
 177 Engraver::internal_make_spanner (SCM x, SCM cause, char const *name,
 178                                  char const *file, int line, char const *fun)
 179 {
 180   Spanner *sp = dynamic_cast<Spanner *> (internal_make_grob (x, cause, name, file, line, fun));
 181   assert (sp);
 182   return sp;
 183 }
 184
 185 Engraver*
 186 unsmob_engraver (SCM eng)
 187 {
 188   return dynamic_cast<Engraver*> (unsmob_translator (eng));
 189 }
 190
 191 bool
 192 ly_is_grob_cause (SCM obj)
 193 {
 194   return unsmob_grob (obj) || unsmob_stream_event (obj) || (obj == SCM_EOL);
 195 }
 196
 197 #include "translator.icc"
 198
 199 ADD_TRANSLATOR (Engraver,
 200                 /* doc */
 201                 "Base class for engravers.  Does nothing, so it is not used.",
 202
 203                 /* create */
 204                 "",
 205
 206                 /* read */
 207                 "",
 208
 209                 /* write */
 210                 ""
 211                 );
 212
 213