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--2004 Jan Nieuwenhuizen <janneke@gnu.org>
   7  */
   8
   9 #include "performer.hh"
  10 #include "event.hh"
  11 #include "audio-item.hh"
  12 #include "audio-column.hh"
  13 #include "global-context.hh"
  14 #include "warn.hh"
  15
  16 class Beam_performer : public Performer {
  17 public:
  18   TRANSLATOR_DECLARATIONS (Beam_performer);
  19
  20 protected:
  21   virtual bool try_music (Music *ev) ;
  22   virtual void start_translation_timestep ();
  23   virtual void process_music ();
  24   void set_melisma (bool);
  25 private:
  26   Music *start_ev_;
  27   Music *now_stop_ev_;
  28   bool beam_;
  29 };
  30
  31 Beam_performer::Beam_performer ()
  32 {
  33   beam_ = false;
  34   start_ev_ = 0;
  35   now_stop_ev_ = 0;
  36 }
  37
  38 void
  39 Beam_performer::process_music ()
  40 {
  41   if (now_stop_ev_)
  42     {
  43       beam_ = false;
  44       set_melisma (false);
  45     }
  46
  47   if (start_ev_)
  48     {
  49       beam_ = true;
  50       set_melisma (true);
  51     }
  52 }
  53
  54
  55 void
  56 Beam_performer::set_melisma (bool ml)
  57 {
  58   SCM b = get_property ("autoBeaming");
  59   if (!to_boolean (b))
  60     daddy_context_->set_property ("beamMelismaBusy", ml ? SCM_BOOL_T :SCM_BOOL_F);
  61 }
  62
  63 void
  64 Beam_performer::start_translation_timestep ()
  65 {
  66   start_ev_ = 0;
  67   now_stop_ev_ = 0;
  68 }
  69
  70 bool
  71 Beam_performer::try_music (Music *m)
  72 {
  73   if (m->is_mus_type ("beam-event"))
  74     {
  75       Direction d = to_dir (m->get_property ("span-direction"));
  76
  77       if (d == START)
  78         {
  79           start_ev_ = m;
  80         }
  81       else if (d==STOP)
  82         {
  83           now_stop_ev_ = m;
  84         }
  85       return true;
  86     }
  87   return false;
  88 }
  89
  90 ENTER_DESCRIPTION (Beam_performer,"","",
  91                   "beam-event","","","");
  92