lily/time-signature-performer.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2010 Jan Nieuwenhuizen <janneke@gnu.org>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "audio-item.hh"
  21 #include "performer.hh"
  22 #include "protected-scm.hh"
  23
  24 class Time_signature_performer : public Performer
  25 {
  26 public:
  27   TRANSLATOR_DECLARATIONS (Time_signature_performer);
  28   ~Time_signature_performer ();
  29
  30 protected:
  31
  32   void stop_translation_timestep ();
  33   void process_music ();
  34   virtual void derived_mark () const;
  35   SCM prev_fraction_;
  36 private:
  37
  38   Audio_time_signature *audio_;
  39 };
  40
  41 void
  42 Time_signature_performer::derived_mark () const
  43 {
  44   scm_gc_mark (prev_fraction_);
  45 }
  46
  47 Time_signature_performer::Time_signature_performer ()
  48 {
  49   prev_fraction_ = SCM_BOOL_F;
  50   audio_ = 0;
  51 }
  52
  53 Time_signature_performer::~Time_signature_performer ()
  54 {
  55 }
  56
  57 void
  58 Time_signature_performer::process_music ()
  59 {
  60   SCM fr = get_property ("timeSignatureFraction");
  61   if (scm_is_pair (fr) && !ly_is_equal (fr, prev_fraction_))
  62     {
  63       prev_fraction_ = fr;
  64       int b = scm_to_int (scm_car (fr));
  65       int o = scm_to_int (scm_cdr (fr));
  66
  67       audio_ = new Audio_time_signature (b, o);
  68       Audio_element_info info (audio_, 0);
  69       announce_element (info);
  70     }
  71 }
  72
  73 void
  74 Time_signature_performer::stop_translation_timestep ()
  75 {
  76   if (audio_)
  77     {
  78       audio_ = 0;
  79     }
  80 }
  81
  82 #include "translator.icc"
  83
  84 ADD_TRANSLATOR (Time_signature_performer,
  85                 /* doc */
  86                 "",
  87
  88                 /* create */
  89                 "",
  90
  91                 /* read */
  92                 "",
  93
  94                 /* write */
  95                 ""
  96                 );