lily/rest-collision-engraver.cc

   1 /*
   2   rest-collision-engraver.cc -- implement Rest_collision_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include <set>
  10
  11 #include "duration.hh"
  12 #include "engraver.hh"
  13 #include "international.hh"
  14 #include "item.hh"
  15 #include "moment.hh"
  16 #include "note-column.hh"
  17 #include "paper-column.hh"
  18 #include "rest.hh"
  19 #include "rest-collision.hh"
  20 #include "rhythmic-head.hh"
  21 #include "stream-event.hh"
  22 #include "warn.hh"
  23
  24 class Rest_collision_engraver : public Engraver
  25 {
  26 protected:
  27   Grob *rest_collision_;
  28
  29   void process_acknowledged ();
  30   void stop_translation_timestep ();
  31 public:
  32   TRANSLATOR_DECLARATIONS (Rest_collision_engraver);
  33 };
  34
  35 Rest_collision_engraver::Rest_collision_engraver ()
  36 {
  37   rest_collision_ = 0;
  38 }
  39
  40 void
  41 Rest_collision_engraver::process_acknowledged ()
  42 {
  43   vsize rest_count = 0;
  44   set<Grob*> columns;
  45   Moment now = now_mom ();
  46
  47   for (SCM s = get_property ("busyGrobs"); scm_is_pair (s); s = scm_cdr (s))
  48     {
  49       Grob *g = unsmob_grob (scm_cdar (s));
  50       Moment *m = unsmob_moment (scm_caar (s));
  51       if (!g || !m)
  52         continue;
  53
  54       if (Rhythmic_head::has_interface (g) && (*m) > now)
  55         {
  56           Grob *column = g->get_parent (X_AXIS);
  57           if (!column)
  58             {
  59               g->warning (_ ("rhythmic head is not part of a rhythmic column"));
  60               continue;
  61             }
  62
  63           // Only include rests that start now. Include notes that started any time.
  64           Paper_column *paper_column = dynamic_cast<Item*> (column)->get_column ();
  65           if (!Rest::has_interface (g) || !paper_column || Paper_column::when_mom (paper_column) == now)
  66             {
  67               columns.insert (column);
  68               rest_count += Note_column::has_rests (column);
  69             }
  70         }
  71     }
  72
  73   if (!rest_collision_ && rest_count && columns.size () > 1)
  74     {
  75       rest_collision_ = make_item ("RestCollision", SCM_EOL);
  76       for (set<Grob*>::iterator i = columns.begin (); i != columns.end (); ++i)
  77         Rest_collision::add_column (rest_collision_, *i);
  78     }
  79 }
  80
  81 void
  82 Rest_collision_engraver::stop_translation_timestep ()
  83 {
  84   rest_collision_ = 0;
  85 }
  86
  87 #include "translator.icc"
  88
  89 ADD_TRANSLATOR (Rest_collision_engraver,
  90                 /* doc */
  91                 "Handle collisions of rests.",
  92
  93                 /* create */
  94                 "RestCollision ",
  95
  96                 /* read */
  97                 "busyGrobs ",
  98
  99                 /* write */
 100                 ""
 101                 );