lily/beam-performer.cc

   1 /*
   2   beam-performer.cc -- implement Beam_performer
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1996--2007 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include "performer.hh"
  10 #include "audio-item.hh"
  11 #include "audio-column.hh"
  12 #include "global-context.hh"
  13 #include "stream-event.hh"
  14 #include "warn.hh"
  15
  16 #include "translator.icc"
  17
  18 class Beam_performer : public Performer
  19 {
  20 public:
  21   TRANSLATOR_DECLARATIONS (Beam_performer);
  22
  23 protected:
  24   void start_translation_timestep ();
  25   void process_music ();
  26   void set_melisma (bool);
  27   DECLARE_TRANSLATOR_LISTENER (beam);
  28 private:
  29   Stream_event *start_ev_;
  30   Stream_event *now_stop_ev_;
  31   bool beam_;
  32 };
  33
  34 Beam_performer::Beam_performer ()
  35 {
  36   beam_ = false;
  37   start_ev_ = 0;
  38   now_stop_ev_ = 0;
  39 }
  40
  41 void
  42 Beam_performer::process_music ()
  43 {
  44   if (now_stop_ev_)
  45     {
  46       beam_ = false;
  47       set_melisma (false);
  48     }
  49
  50   if (start_ev_)
  51     {
  52       beam_ = true;
  53       set_melisma (true);
  54     }
  55 }
  56
  57 void
  58 Beam_performer::set_melisma (bool ml)
  59 {
  60   SCM b = get_property ("autoBeaming");
  61   if (!to_boolean (b))
  62     context ()->set_property ("beamMelismaBusy", ml ? SCM_BOOL_T : SCM_BOOL_F);
  63 }
  64
  65 void
  66 Beam_performer::start_translation_timestep ()
  67 {
  68   start_ev_ = 0;
  69   now_stop_ev_ = 0;
  70 }
  71
  72 IMPLEMENT_TRANSLATOR_LISTENER (Beam_performer, beam);
  73 void
  74 Beam_performer::listen_beam (Stream_event *ev)
  75 {
  76   Direction d = to_dir (ev->get_property ("span-direction"));
  77
  78   if (d == START)
  79     start_ev_ = ev;
  80   else if (d == STOP)
  81     now_stop_ev_ = ev;
  82 }
  83
  84 ADD_TRANSLATOR (Beam_performer,
  85                 /* doc */
  86                 "",
  87
  88                 /* create */
  89                 "",
  90
  91                 /* read */
  92                 "",
  93
  94                 /* write */
  95                 ""
  96                 );
  97