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--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7  */
   8
   9 #include "spanner.hh"
  10 #include "warn.hh"
  11 #include "side-position-interface.hh"
  12 #include "global-context.hh"
  13 #include "engraver.hh"
  14
  15 class Measure_grouping_engraver : public Engraver
  16 {
  17 public:
  18   TRANSLATOR_DECLARATIONS (Measure_grouping_engraver);
  19
  20 protected:
  21   Spanner * grouping_;
  22   Rational stop_grouping_mom_;
  23
  24   virtual void process_music ();
  25   virtual void finalize ();
  26   virtual void acknowledge_grob (Grob_info);
  27 };
  28
  29 void
  30 Measure_grouping_engraver::finalize ()
  31 {
  32   if (grouping_)
  33     {
  34       grouping_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
  35       grouping_->suicide ();
  36       grouping_= 0;
  37     }
  38 }
  39
  40
  41 void
  42 Measure_grouping_engraver::acknowledge_grob (Grob_info gi)
  43 {
  44   if (grouping_)
  45     {
  46       Side_position_interface::add_support (grouping_, gi.grob_);
  47     }
  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 grouping = get_property ("beatGrouping");
  66   if (ly_c_pair_p (grouping))
  67     {
  68       Moment *measpos = unsmob_moment (get_property ("measurePosition"));
  69       Rational mp = measpos->main_part_;
  70
  71       Moment * beatlen = unsmob_moment (get_property ("beatLength"));
  72       Rational bl = beatlen->main_part_;
  73
  74       Rational where (0);
  75       for (SCM s = grouping; ly_c_pair_p (s);
  76            where += Rational (ly_scm2int (ly_car (s))) * bl,
  77            s = ly_cdr (s)
  78            )
  79         {
  80           int grouplen = ly_scm2int (ly_car (s));
  81           if (where == mp)
  82             {
  83               if (grouping_)
  84                 {
  85                   programming_error ("Huh, last grouping not finished yet.");
  86                   continue;
  87                 }
  88
  89               grouping_ = make_spanner ("MeasureGrouping", SCM_EOL);
  90               grouping_->set_bound (LEFT, unsmob_grob (get_property ("currentMusicalColumn")));
  91
  92
  93
  94               stop_grouping_mom_ = now.main_part_ + Rational (grouplen - 1) * bl ;
  95               get_global_context ()->add_moment_to_process (Moment (stop_grouping_mom_));
  96
  97               if (grouplen == 3)
  98                 grouping_->set_property ("style", ly_symbol2scm ("triangle"));
  99               else
 100                 grouping_->set_property ("style", ly_symbol2scm ("bracket"));
 101
 102               break ;
 103             }
 104         }
 105     }
 106 }
 107 Measure_grouping_engraver::Measure_grouping_engraver ()
 108 {
 109   grouping_ = 0;
 110 }
 111
 112 ENTER_DESCRIPTION (Measure_grouping_engraver,
 113 /* descr */       "Creates Measure_grouping objects using beatGrouping property",
 114 /* creats*/       "MeasureGrouping",
 115 /* accepts */     "",
 116 /* acks  */      "note-column-interface",
 117 /* reads */       "beatGrouping beatLength measurePosition currentMusicalColumn",
 118 /* write */       "");