lily/grace-spacing-engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2006--2011 Han-Wen <hanwen@lilypond.org>
   5
   6
   7   LilyPond is free software: you can redistribute it and/or modify
   8   it under the terms of the GNU General Public License as published by
   9   the Free Software Foundation, either version 3 of the License, or
  10   (at your option) any later version.
  11
  12   LilyPond is distributed in the hope that it will be useful,
  13   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15   GNU General Public License for more details.
  16
  17   You should have received a copy of the GNU General Public License
  18   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "engraver.hh"
  22 #include "moment.hh"
  23 #include "pointer-group-interface.hh"
  24 #include "spanner.hh"
  25
  26 #include "translator.icc"
  27
  28 class Grace_spacing_engraver : public Engraver
  29 {
  30   TRANSLATOR_DECLARATIONS (Grace_spacing_engraver);
  31
  32 protected:
  33
  34   Moment last_moment_;
  35   Spanner *grace_spacing_;
  36
  37   void process_music ();
  38   void stop_translation_timestep ();
  39 };
  40
  41
  42 Grace_spacing_engraver::Grace_spacing_engraver ()
  43 {
  44   grace_spacing_ = 0;
  45 }
  46
  47 void
  48 Grace_spacing_engraver::process_music ()
  49 {
  50   Moment now = now_mom ();
  51   if (!last_moment_.grace_part_ and now.grace_part_)
  52     {
  53       grace_spacing_ = make_spanner ("GraceSpacing", SCM_EOL);
  54     }
  55
  56
  57   if (grace_spacing_ && (now.grace_part_ || last_moment_.grace_part_))
  58     {
  59       Grob *column = unsmob_grob (get_property ("currentMusicalColumn"));
  60       Pointer_group_interface::add_grob (grace_spacing_,
  61                                          ly_symbol2scm ("columns"),
  62                                          column);
  63
  64       column->set_object ("grace-spacing", grace_spacing_->self_scm ());
  65
  66       if (!grace_spacing_->get_bound (LEFT))
  67         grace_spacing_->set_bound (LEFT, column);
  68       else
  69         grace_spacing_->set_bound (RIGHT, column);
  70     }
  71 }
  72
  73 void
  74 Grace_spacing_engraver::stop_translation_timestep ()
  75 {
  76   last_moment_ = now_mom ();
  77
  78   if (!last_moment_.grace_part_)
  79     grace_spacing_ = 0;
  80 }
  81
  82
  83 ADD_TRANSLATOR (Grace_spacing_engraver,
  84                 "Bookkeeping of shortest starting and playing notes in grace"
  85                 " note runs.",
  86
  87                 /* create */
  88                 "GraceSpacing ",
  89
  90                 /* read */
  91                 "currentMusicalColumn ",
  92
  93                 /* write */
  94                 ""
  95                 );