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       typeset_grob (grouping_);
  36       grouping_->suicide ();
  37       grouping_= 0;
  38     }
  39 }
  40
  41
  42 void
  43 Measure_grouping_engraver::acknowledge_grob (Grob_info gi)
  44 {
  45   if (grouping_)
  46     {
  47       Side_position_interface::add_support (grouping_, gi.grob_);
  48     }
  49 }
  50
  51 void
  52 Measure_grouping_engraver::process_music ()
  53 {
  54   Moment now = now_mom ();
  55   if (grouping_ && now.main_part_ >= stop_grouping_mom_ && !now.grace_part_)
  56     {
  57       grouping_->set_bound (RIGHT,
  58                             unsmob_grob (get_property ("currentMusicalColumn")));
  59       typeset_grob (grouping_);
  60       grouping_ = 0;
  61     }
  62
  63   if (now.grace_part_)
  64     return;
  65
  66   SCM grouping = get_property ("beatGrouping");
  67   if (gh_pair_p (grouping))
  68     {
  69       Moment *measpos = unsmob_moment (get_property ("measurePosition"));
  70       Rational mp = measpos->main_part_;
  71
  72       Moment * beatlen = unsmob_moment (get_property ("beatLength"));
  73       Rational bl = beatlen->main_part_;
  74
  75       Rational where (0);
  76       for (SCM s = grouping; gh_pair_p (s);
  77            where += Rational (gh_scm2int (gh_car (s))) * bl,
  78            s = gh_cdr (s)
  79            )
  80         {
  81           int grouplen = gh_scm2int (gh_car (s));
  82           if (where == mp)
  83             {
  84               if (grouping_)
  85                 {
  86                   programming_error ("Huh, last grouping not finished yet.");
  87                   continue;
  88                 }
  89
  90               grouping_ = make_spanner ("MeasureGrouping");
  91               grouping_->set_bound (LEFT, unsmob_grob (get_property ("currentMusicalColumn")));
  92               announce_grob (grouping_, SCM_EOL);
  93
  94
  95               stop_grouping_mom_ = now.main_part_ + Rational (grouplen - 1) * bl ;
  96               get_global_context ()->add_moment_to_process (Moment (stop_grouping_mom_));
  97
  98               if (grouplen == 3)
  99                 grouping_->set_property ("style", ly_symbol2scm ("triangle"));
 100               else
 101                 grouping_->set_property ("style", ly_symbol2scm ("bracket"));
 102
 103               break ;
 104             }
 105         }
 106     }
 107 }
 108 Measure_grouping_engraver::Measure_grouping_engraver ()
 109 {
 110   grouping_ = 0;
 111 }
 112
 113 ENTER_DESCRIPTION (Measure_grouping_engraver,
 114 /* descr */       "Creates Measure_grouping objects using beatGrouping property",
 115 /* creats*/       "MeasureGrouping",
 116 /* accepts */     "",
 117 /* acks  */      "note-column-interface",
 118 /* reads */       "beatGrouping beatLength measurePosition currentMusicalColumn",
 119 /* write */       "");