lily/figured-bass-engraver.cc

   1 /*
   2 figured-bass-engraver.cc --  implement Figured_bass_engraver
   3
   4 source file of the GNU LilyPond music typesetter
   5
   6 (c) 2002--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "engraver.hh"
  11 #include "text-item.hh"
  12 #include "event.hh"
  13 #include "item.hh"
  14 #include "context.hh"
  15
  16 class Figured_bass_engraver : public Engraver
  17 {
  18   TRANSLATOR_DECLARATIONS (Figured_bass_engraver);
  19 protected:
  20   Link_array<Music> figures_;
  21   Music * rest_req_;
  22
  23   Grob * figure_;
  24
  25   virtual bool try_music (Music*);
  26   virtual void stop_translation_timestep ();
  27   virtual void process_music ();
  28 };
  29
  30
  31 Figured_bass_engraver::Figured_bass_engraver ()
  32 {
  33   figure_ = 0;
  34   rest_req_ = 0;
  35 }
  36
  37 void
  38 Figured_bass_engraver::stop_translation_timestep ()
  39 {
  40   figure_ = 0;
  41
  42   figures_.clear ();
  43   rest_req_ = 0;
  44 }
  45
  46 bool
  47 Figured_bass_engraver::try_music (Music*m)
  48 {
  49   if (m->is_mus_type ("bass-figure-event"))
  50     {
  51       figures_.push (m);
  52       return true;
  53     }
  54   else if (m->is_mus_type ("rest-event"))
  55     {
  56       rest_req_ = m;
  57       return true;
  58     }
  59   return false;
  60 }
  61
  62 void
  63 Figured_bass_engraver::process_music ()
  64 {
  65   if (rest_req_)
  66     {
  67       figure_ = make_item ("BassFigure", rest_req_->self_scm ());
  68       figure_->set_property ("text" , scm_makfrom0str ("-"));
  69     }
  70   else if (figures_.size ())
  71     {
  72       SCM proc = get_property ("bassFigureFormatFunction");
  73       if (ly_c_procedure_p (proc))
  74         {
  75           SCM l = SCM_EOL;
  76           SCM * t = &l;
  77           for (int i = 0; i < figures_.size (); i++)
  78             {
  79               *t = scm_cons (figures_[i]->self_scm (), SCM_EOL);
  80               t = SCM_CDRLOC (*t);
  81             }
  82           figure_ = make_item ("BassFigure", figures_[0]->self_scm ());
  83           scm_call_3 (proc, l, context ()->self_scm (),
  84                       figure_->self_scm ());
  85         }
  86     }
  87 }
  88
  89
  90 ENTER_DESCRIPTION (Figured_bass_engraver,
  91 /* descr */       "Make figured bass numbers.",
  92 /* creats*/       "BassFigure",
  93 /* accepts */     "rest-event bass-figure-event",
  94 /* acks  */      "",
  95 /* reads */       "bassFigureFormatFunction",
  96 /* write */       "");