lily/keep-alive-together-engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2010--2011 Joe Neeman <joeneeman@gmail.com>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "context.hh"
  21 #include "dispatcher.hh"
  22 #include "engraver.hh"
  23 #include "grob.hh"
  24 #include "grob-array.hh"
  25
  26 #include "translator.icc"
  27
  28 class Keep_alive_together_engraver: public Engraver
  29 {
  30   vector<Grob*> group_spanners_;
  31
  32 public:
  33   TRANSLATOR_DECLARATIONS (Keep_alive_together_engraver);
  34   DECLARE_ACKNOWLEDGER (hara_kiri_group_spanner);
  35
  36   virtual void finalize ();
  37 };
  38
  39 Keep_alive_together_engraver::Keep_alive_together_engraver ()
  40 {
  41 }
  42
  43 void
  44 Keep_alive_together_engraver::acknowledge_hara_kiri_group_spanner (Grob_info i)
  45 {
  46   group_spanners_.push_back (i.grob ());
  47 }
  48
  49 void
  50 Keep_alive_together_engraver::finalize ()
  51 {
  52   for (vsize i = 0; i < group_spanners_.size (); ++i)
  53     {
  54       SCM grob_array_scm = Grob_array::make_array ();
  55       Grob_array *ga = unsmob_grob_array (grob_array_scm);
  56
  57       // It would make Hara_kiri_group_spanner::request_suicide a _little_
  58       // faster if we removed each grob from its own array. It seems
  59       // unnecessary for now, though.
  60       ga->set_array (group_spanners_);
  61       group_spanners_[i]->set_object ("keep-alive-with", grob_array_scm);
  62     }
  63 }
  64
  65 ADD_ACKNOWLEDGER (Keep_alive_together_engraver, hara_kiri_group_spanner);
  66
  67 ADD_TRANSLATOR (Keep_alive_together_engraver,
  68                 /* doc */
  69                 "This engraver collects all @code{Hara_kiri_group_spanner}s "
  70                 "that are created in contexts at or below its own.  "
  71                 "These spanners are then tied together so that one will "
  72                 "be removed only if all are removed.  For example, "
  73                 "if a @code{StaffGroup} uses this engraver, then the staves "
  74                 "in the group will all be visible as long as there is a note "
  75                 "in at least one of them.",
  76
  77                 /* create */
  78                 "",
  79
  80                 /* read */
  81                 "",
  82
  83                 /* write */
  84                 ""
  85                 );