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 do_try_music (Music *m);
  21   virtual void acknowledge_element (Score_element_info);
  22 };
  23
  24 ADD_THIS_TRANSLATOR (Voice_devnull_engraver);
  25
  26 static char const *eat_spanners[] = {
  27   "beam-interface",
  28   "slur",
  29   "dynamic-interface",
  30   "crescendo-interface",
  31   0
  32 };
  33
  34 bool
  35 Voice_devnull_engraver::do_try_music (Music *m)
  36 {
  37   if (daddy_trans_l_->id_str_ == "two"
  38       && (to_boolean (get_property ("unison"))
  39           || to_boolean (get_property ("unisilence"))))
  40     {
  41       for (char const **p = eat_spanners; *p; p++)
  42         {
  43           if (Span_req *s = dynamic_cast <Span_req *> (m))
  44             {
  45               if (s->span_type_str_ == *p)
  46                 {
  47                   return true;
  48                 }
  49             }
  50         }
  51     }
  52   return false;
  53 }
  54
  55 static char const *junk_interfaces[] = {
  56 #if 0
  57   "beam-interface",
  58 #endif
  59   "slur-interface",
  60   "tie-interface",
  61   "text-item-interface",
  62   "text-script-interface",
  63   "dynamic-interface",
  64   "crescendo-interface",
  65   0
  66 };
  67
  68 void
  69 Voice_devnull_engraver::acknowledge_element (Score_element_info i)
  70 {
  71   if (daddy_trans_l_->id_str_ == "two"
  72       && (to_boolean (get_property ("unison"))
  73           || to_boolean (get_property ("unisilence"))))
  74     for (char const **p = junk_interfaces; *p; p++)
  75       if (i.elem_l_->has_interface (ly_symbol2scm (*p)))
  76         {
  77           i.elem_l_->suicide ();
  78           return;
  79         }
  80 }