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--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7  */
   8
   9 #include "score-engraver.hh"
  10 #include "spanner.hh"
  11 #include "warn.hh"
  12 #include "side-position-interface.hh"
  13
  14 class Measure_grouping_engraver : public Engraver
  15 {
  16 public:
  17   TRANSLATOR_DECLARATIONS(Measure_grouping_engraver);
  18
  19 protected:
  20   Spanner * grouping_;
  21   Rational stop_grouping_mom_;
  22
  23   virtual void process_music ();
  24   virtual void finalize ();
  25   virtual void acknowledge_grob (Grob_info);
  26 };
  27
  28 void
  29 Measure_grouping_engraver::finalize()
  30 {
  31   if (grouping_)
  32     {
  33       grouping_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
  34       typeset_grob (grouping_);
  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       typeset_grob (grouping_);
  59       grouping_ = 0;
  60     }
  61
  62   if (now.grace_part_)
  63     return;
  64
  65   SCM grouping = get_property ("beatGrouping");
  66   if (gh_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; gh_pair_p (s);
  76            where += Rational (gh_scm2int (gh_car (s))) * bl,
  77            s = gh_cdr (s)
  78            )
  79         {
  80           int grouplen = gh_scm2int (gh_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_ = new Spanner (get_property ("MeasureGrouping"));
  90               grouping_->set_bound (LEFT, unsmob_grob (get_property ("currentMusicalColumn")));
  91               announce_grob (grouping_, SCM_EOL);
  92
  93
  94               stop_grouping_mom_ = now.main_part_ + Rational(grouplen - 1) * bl ;
  95               top_engraver ()->add_moment_to_process (Moment (stop_grouping_mom_));
  96
  97               if (grouplen == 3)
  98                 grouping_->set_grob_property ("style", ly_symbol2scm ("triangle"));
  99               else
 100                 grouping_->set_grob_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 */       "");