lily/measure-grouping-engraver.cc

   1 /*
   2   measure-grouping-engraver.cc -- implement Measure_grouping_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2002--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "warn.hh"
  10 #include "side-position-interface.hh"
  11 #include "global-context.hh"
  12 #include "engraver.hh"
  13 #include "spanner.hh"
  14 #include "beam-settings.hh"
  15
  16 #include "translator.icc"
  17
  18 class Measure_grouping_engraver : public Engraver
  19 {
  20 public:
  21   TRANSLATOR_DECLARATIONS (Measure_grouping_engraver);
  22
  23 protected:
  24   Spanner *grouping_;
  25   Rational stop_grouping_mom_;
  26
  27   void process_music ();
  28   virtual void finalize ();
  29   DECLARE_ACKNOWLEDGER (note_column);
  30 };
  31
  32 void
  33 Measure_grouping_engraver::finalize ()
  34 {
  35   if (grouping_)
  36     {
  37       grouping_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
  38       grouping_->suicide ();
  39       grouping_ = 0;
  40     }
  41 }
  42
  43 void
  44 Measure_grouping_engraver::acknowledge_note_column (Grob_info gi)
  45 {
  46   if (grouping_)
  47     Side_position_interface::add_support (grouping_, gi.grob ());
  48 }
  49
  50 void
  51 Measure_grouping_engraver::process_music ()
  52 {
  53   Moment now = now_mom ();
  54   if (grouping_ && now.main_part_ >= stop_grouping_mom_ && !now.grace_part_)
  55     {
  56       grouping_->set_bound (RIGHT,
  57                             unsmob_grob (get_property ("currentMusicalColumn")));
  58
  59       grouping_ = 0;
  60     }
  61
  62   if (now.grace_part_)
  63     return;
  64
  65   SCM settings = get_property ("beamSettings");
  66   SCM grouping = SCM_EOL;
  67   if (scm_is_pair (settings))
  68     {
  69       SCM time_signature_fraction = get_property ("timeSignatureFraction");
  70       grouping = ly_beam_grouping (settings,
  71                                    time_signature_fraction,
  72                                    ly_symbol2scm ("end"),
  73                                    ly_symbol2scm ("*"));
  74     }
  75   if (scm_is_pair (grouping))
  76     {
  77       Moment *measpos = unsmob_moment (get_property ("measurePosition"));
  78       Rational mp = measpos->main_part_;
  79
  80       Moment *beatlen_mom = unsmob_moment (get_property ("beatLength"));
  81       Rational beat_length = beatlen_mom->main_part_;
  82
  83       Rational where (0);
  84       for (SCM s = grouping; scm_is_pair (s);
  85            where += Rational ((int) scm_to_int (scm_car (s))) * beat_length,
  86              s = scm_cdr (s))
  87         {
  88           int grouplen = scm_to_int (scm_car (s));
  89           if (where == mp)
  90             {
  91               if (grouping_)
  92                 {
  93                   programming_error ("last grouping not finished yet");
  94                   continue;
  95                 }
  96               if (grouplen > 1)
  97                {
  98                  grouping_ = make_spanner ("MeasureGrouping", SCM_EOL);
  99                  grouping_->set_bound (LEFT, unsmob_grob (get_property ("currentMusicalColumn")));
 100
 101                  stop_grouping_mom_ = now.main_part_ + Rational (grouplen - 1) * beat_length;
 102                  get_global_context ()->add_moment_to_process (Moment (stop_grouping_mom_));
 103
 104                  if (grouplen == 3)
 105                    grouping_->set_property ("style", ly_symbol2scm ("triangle"));
 106                  else
 107                    grouping_->set_property ("style", ly_symbol2scm ("bracket"));
 108
 109                  break;
 110                }
 111             }
 112         }
 113     }
 114 }
 115
 116 Measure_grouping_engraver::Measure_grouping_engraver ()
 117 {
 118   grouping_ = 0;
 119 }
 120
 121 ADD_ACKNOWLEDGER (Measure_grouping_engraver, note_column);
 122 ADD_TRANSLATOR (Measure_grouping_engraver,
 123                 /* doc */
 124                 "Create @code{MeasureGrouping} to indicate beat subdivision.",
 125
 126                 /* create */
 127                 "MeasureGrouping ",
 128
 129                 /* read */
 130                 "beatLength "
 131                 "currentMusicalColumn "
 132                 "measurePosition "
 133                 "beamSettings ",
 134
 135                 /* write */
 136                 ""
 137                 );