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--2000 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include "audio-item.hh"
  10 #include "lily-proto.hh"
  11 #include "performer.hh"
  12
  13
  14 class Time_signature_performer : public Performer
  15 {
  16 public:
  17   VIRTUAL_COPY_CONS(Translator);
  18
  19   Time_signature_performer();
  20   ~Time_signature_performer();
  21
  22 protected:
  23
  24   virtual void stop_translation_timestep ();
  25   virtual void create_audio_elements ();
  26
  27   SCM prev_fraction_;
  28 private:
  29   Time_signature_change_req* time_signature_req_l_;
  30   Audio_time_signature* audio_p_;
  31 };
  32
  33
  34 Time_signature_performer::Time_signature_performer ()
  35 {
  36   prev_fraction_ = SCM_BOOL_F;
  37   audio_p_ = 0;
  38 }
  39
  40 Time_signature_performer::~Time_signature_performer ()
  41 {
  42 }
  43
  44
  45 void
  46 Time_signature_performer::create_audio_elements ()
  47 {
  48   SCM fr = get_property ("timeSignatureFraction");
  49   if (gh_pair_p (fr)
  50       && scm_equal_p (fr, prev_fraction_) != SCM_BOOL_T)
  51     {
  52       int b = gh_scm2int (gh_car (fr));
  53       int o = gh_scm2int (gh_cdr (fr));
  54
  55       audio_p_ = new Audio_time_signature (b,o);
  56       Audio_element_info info (audio_p_, 0);
  57       announce_element (info);
  58       time_signature_req_l_ = 0;
  59     }
  60 }
  61
  62 void
  63 Time_signature_performer::stop_translation_timestep ()
  64 {
  65   if (audio_p_)
  66     {
  67       play_element (audio_p_);
  68       audio_p_ = 0;
  69     }
  70 }
  71 ADD_THIS_TRANSLATOR (Time_signature_performer);
  72