lily/time-signature-performer.cc

   1 /*
   2   time-signature-performer.cc -- implement Time_signature_performer
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2007 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include "audio-item.hh"
  10 #include "performer.hh"
  11 #include "protected-scm.hh"
  12
  13 class Time_signature_performer : public Performer
  14 {
  15 public:
  16   TRANSLATOR_DECLARATIONS (Time_signature_performer);
  17   ~Time_signature_performer ();
  18
  19 protected:
  20
  21   void stop_translation_timestep ();
  22   void process_music ();
  23   virtual void derived_mark () const;
  24   SCM prev_fraction_;
  25 private:
  26
  27   Audio_time_signature *audio_;
  28 };
  29
  30 void
  31 Time_signature_performer::derived_mark () const
  32 {
  33   scm_gc_mark (prev_fraction_);
  34 }
  35
  36 Time_signature_performer::Time_signature_performer ()
  37 {
  38   prev_fraction_ = SCM_BOOL_F;
  39   audio_ = 0;
  40 }
  41
  42 Time_signature_performer::~Time_signature_performer ()
  43 {
  44 }
  45
  46 void
  47 Time_signature_performer::process_music ()
  48 {
  49   SCM fr = get_property ("timeSignatureFraction");
  50   if (scm_is_pair (fr) && !ly_is_equal (fr, prev_fraction_))
  51     {
  52       prev_fraction_ = fr;
  53       int b = scm_to_int (scm_car (fr));
  54       int o = scm_to_int (scm_cdr (fr));
  55
  56       audio_ = new Audio_time_signature (b, o);
  57       Audio_element_info info (audio_, 0);
  58       announce_element (info);
  59     }
  60 }
  61
  62 void
  63 Time_signature_performer::stop_translation_timestep ()
  64 {
  65   if (audio_)
  66     {
  67       audio_ = 0;
  68     }
  69 }
  70
  71 #include "translator.icc"
  72
  73 ADD_TRANSLATOR (Time_signature_performer, "", "", "", "");