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 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   VIRTUAL_COPY_CONS (Translator);
  18
  19 protected:
  20   virtual bool try_music (Music *m);
  21   virtual void acknowledge_grob (Grob_info);
  22 };
  23
  24 ADD_THIS_TRANSLATOR (Voice_devnull_engraver);
  25
  26 static char const *eat_spanners[] = {
  27   "beam-interface",
  28   "slur",
  29   "tie",
  30   "dynamic-interface",
  31   "crescendo-interface",
  32   0
  33 };
  34
  35 bool
  36 Voice_devnull_engraver::try_music (Music *m)
  37 {
  38   SCM s = get_property ("devNullVoice");
  39 #if 0
  40   /* No need */
  41   if (gh_equal_p (s, ly_symbol2scm ("never")))
  42     return;
  43 #endif
  44
  45   if (gh_equal_p (s, ly_symbol2scm ("allways"))
  46       || (s == SCM_EOL
  47           && daddy_trans_l_->id_str_.left_str (3) == "two"
  48           && (to_boolean (get_property ("unison"))
  49               || to_boolean (get_property ("unisilence")))))
  50     {
  51       for (char const **p = eat_spanners; *p; p++)
  52         {
  53           if (Span_req *s = dynamic_cast <Span_req *> (m))
  54             {
  55               if (scm_equal_p (s->get_mus_property ("span-type"),
  56                                ly_str02scm ( *p)) == SCM_BOOL_T)
  57                 {
  58                   return true;
  59                 }
  60             }
  61         }
  62     }
  63   return false;
  64 }
  65
  66 static char const *junk_interfaces[] = {
  67 #if 0
  68   "beam-interface",
  69 #endif
  70   "slur-interface",
  71   "tie-interface",
  72   "text-item-interface",
  73   "text-script-interface",
  74   "dynamic-interface",
  75   "crescendo-interface",
  76   0
  77 };
  78
  79 void
  80 Voice_devnull_engraver::acknowledge_grob (Grob_info i)
  81 {
  82   SCM s = get_property ("devNullVoice");
  83 #if 0
  84   /* No need */
  85   if (gh_equal_p (s, ly_symbol2scm ("never")))
  86     return;
  87 #endif
  88
  89   if (gh_equal_p (s, ly_symbol2scm ("allways"))
  90       || (gh_equal_p (s, ly_symbol2scm ("unisolo"))
  91           && daddy_trans_l_->id_str_.left_str (3) == "two"
  92           && (to_boolean (get_property ("unison"))
  93               || to_boolean (get_property ("unisilence")))))
  94     for (char const **p = junk_interfaces; *p; p++)
  95       if (i.elem_l_->has_interface (ly_symbol2scm (*p)))
  96         {
  97           i.elem_l_->suicide ();
  98           return;
  99         }
 100 }
 101