lily/voice-devnull-engraver.cc

   1 /*
   2   voice-devnull-engraver.cc -- implement Voice_devnull_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000--2002 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include "engraver.hh"
  10 #include "item.hh"
  11 #include "musical-request.hh"
  12 #include "translator-group.hh"
  13
  14 class Voice_devnull_engraver : public Engraver
  15 {
  16 public:
  17   TRANSLATOR_DECLARATIONS(Voice_devnull_engraver);
  18
  19 protected:
  20   virtual bool try_music (Music *m);
  21   virtual void acknowledge_grob (Grob_info);
  22 };
  23
  24
  25
  26 static char const *eat_spanners[] = {
  27   "beam",
  28   "crescendo",
  29   "decrescendo",
  30   "rest",
  31   "slur",
  32   0
  33 };
  34
  35 bool
  36 Voice_devnull_engraver::try_music (Music *m)
  37 {
  38   SCM s = get_property ("devNullVoice");
  39
  40 #if 0
  41   /* No need */
  42   if (gh_equal_p (s, ly_symbol2scm ("never")))
  43     return;
  44 #endif
  45
  46   if (gh_equal_p (s, ly_symbol2scm ("always"))
  47       || (s == SCM_EOL
  48           && daddy_trans_->id_string_.left_string (3) == "two"
  49           && (to_boolean (get_property ("unison"))
  50               || to_boolean (get_property ("unisilence")))))
  51     {
  52       if (Span_req *s = dynamic_cast <Span_req *> (m))
  53         {
  54           SCM t = s->get_mus_property ("span-type");
  55
  56           for (char const **p = eat_spanners; *p; p++)
  57             {
  58               if (t == ly_str02scm (*p))
  59                 return true;
  60             }
  61         }
  62       /* Ugh.  Should eat other requests, script etc. too. */
  63       else if (dynamic_cast<Tie_req*> (m))
  64         return true;
  65     }
  66   return false;
  67 }
  68
  69 static char const *junk_interfaces[] = {
  70   "beam-interface",
  71   "dynamic-interface",
  72   "hairpin-interface",
  73   "multi-measure-rest-interface",
  74   "script-interface",
  75   "slur-interface",
  76   "text-interface",
  77   "text-item-interface",
  78   "text-script-interface",
  79   "text-spanner-interface",
  80   "tie-interface",
  81   0
  82 };
  83
  84 void
  85 Voice_devnull_engraver::acknowledge_grob (Grob_info i)
  86 {
  87   SCM s = get_property ("devNullVoice");
  88 #if 0
  89   /* No need, next if will never be true */
  90   if (s == ly_symbol2scm ("never"))
  91     return;
  92 #endif
  93
  94 #if 0  /* We used to have have this until 1.5.68.  Not sure about
  95           soloADue requirement */
  96   if (s == ly_symbol2scm ("always")
  97       || (s == SCM_EOL
  98           && daddy_trans_->id_string_.left_string (3) == "two"
  99           && (to_boolean (get_property ("unison"))
 100               || to_boolean (get_property ("unisilence")))))
 101 #else
 102     if (s == ly_symbol2scm ("always")
 103         || (s == SCM_EOL
 104             && to_boolean (get_property ("soloADue"))
 105             && ((daddy_trans_->id_string_.left_string (3) == "two"
 106                  && (to_boolean (get_property ("unison"))
 107                      || to_boolean (get_property ("unisilence"))))
 108
 109                 /* Maybe this should be optional? */
 110               || to_boolean (get_property ("othersolo")))))
 111 #endif
 112
 113     for (char const **p = junk_interfaces; *p; p++)
 114       if (i.grob_->internal_has_interface (ly_symbol2scm (*p)))
 115         {
 116           i.grob_->suicide ();
 117           return;
 118         }
 119 }
 120
 121 Voice_devnull_engraver::Voice_devnull_engraver(){}
 122
 123 ENTER_DESCRIPTION(Voice_devnull_engraver,
 124 /* descr */       "Kill off certain items and spanners if we're Voice `two' and unison or unisilence is set.",
 125 /* creats*/       "",
 126 /* acks  */       "grob-interface",
 127 /* reads */       "",
 128 /* write */       "");