lily/note-spacing-engraver.cc

   1 /*
   2   note-spacing-engraver.cc -- implement Note_spacing_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2006 Han-Wen Nienhuys <hanwen@lilypond.org>
   7
   8 */
   9
  10 #include "engraver.hh"
  11
  12 #include "grob-array.hh"
  13 #include "context.hh"
  14 #include "item.hh"
  15 #include "pointer-group-interface.hh"
  16
  17 #include "translator.icc"
  18
  19 class Note_spacing_engraver : public Engraver
  20 {
  21   Grob *last_spacing_;
  22   Context *last_spacing_parent_context_;
  23
  24   Grob *spacing_;
  25
  26   void add_spacing_item (Grob *);
  27   TRANSLATOR_DECLARATIONS (Note_spacing_engraver);
  28 protected:
  29
  30   DECLARE_ACKNOWLEDGER (rhythmic_grob);
  31   DECLARE_ACKNOWLEDGER (note_column);
  32   void stop_translation_timestep ();
  33   virtual void finalize ();
  34   virtual void derived_mark () const;
  35 };
  36
  37 void
  38 Note_spacing_engraver::derived_mark () const
  39 {
  40   if (last_spacing_parent_context_)
  41     scm_gc_mark (last_spacing_parent_context_->self_scm ());
  42 }
  43
  44 Note_spacing_engraver::Note_spacing_engraver ()
  45 {
  46   last_spacing_parent_context_ = 0;
  47   last_spacing_ = 0;
  48   spacing_ = 0;
  49 }
  50
  51 void
  52 Note_spacing_engraver::add_spacing_item (Grob *g)
  53 {
  54   if (!spacing_)
  55     {
  56       spacing_ = make_item ("NoteSpacing", g->self_scm ());
  57     }
  58
  59   if (spacing_)
  60     {
  61       Pointer_group_interface::add_grob (spacing_,
  62                                          ly_symbol2scm ("left-items"),
  63                                          g);
  64
  65       if (last_spacing_)
  66         Pointer_group_interface::add_grob (last_spacing_,
  67                                            ly_symbol2scm ("right-items"),
  68                                            g);
  69     }
  70 }
  71
  72
  73 void
  74 Note_spacing_engraver::acknowledge_note_column (Grob_info gi)
  75 {
  76   add_spacing_item (gi.grob ());
  77 }
  78
  79 void
  80 Note_spacing_engraver::acknowledge_rhythmic_grob (Grob_info gi)
  81 {
  82   add_spacing_item (gi.grob ());
  83 }
  84
  85 void
  86 Note_spacing_engraver::finalize ()
  87 {
  88   if (last_spacing_
  89       && last_spacing_parent_context_
  90       && last_spacing_parent_context_ == context ()->get_parent_context ()
  91       && !unsmob_grob_array (last_spacing_->get_object ("right-items")))
  92     {
  93       SCM ccol = get_property ("currentCommandColumn");
  94       Grob *column = unsmob_grob (ccol);
  95
  96       Pointer_group_interface::add_grob (last_spacing_,
  97                                          ly_symbol2scm ("right-items"),
  98                                          column);
  99     }
 100 }
 101
 102 void
 103 Note_spacing_engraver::stop_translation_timestep ()
 104 {
 105   if (last_spacing_
 106       && last_spacing_parent_context_
 107       && last_spacing_parent_context_ == context ()->get_parent_context ())
 108     {
 109       Grob *sep = unsmob_grob (get_property ("breakableSeparationItem"));
 110       if (sep)
 111         Pointer_group_interface::add_grob (last_spacing_,
 112                                            ly_symbol2scm ("right-items"),
 113                                            sep);
 114     }
 115
 116   if (spacing_)
 117     {
 118       last_spacing_ = spacing_;
 119       last_spacing_parent_context_ = context ()->get_parent_context ();
 120       spacing_ = 0;
 121     }
 122
 123 }
 124
 125 ADD_ACKNOWLEDGER (Note_spacing_engraver, note_column);
 126 ADD_ACKNOWLEDGER (Note_spacing_engraver, rhythmic_grob);
 127
 128 ADD_TRANSLATOR (Note_spacing_engraver,
 129                 /* doc */ "Generates NoteSpacing, an object linking horizontal lines for use in spacing.",
 130                 /* create */ "NoteSpacing",
 131                 /* read */ "",
 132                 /* write */ "");