lily/instrument-switch-engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2006--2011 Han-Wen Nienhuys <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 "item.hh"
  23 #include "text-interface.hh"
  24
  25 #include "translator.icc"
  26
  27
  28 class Instrument_switch_engraver : public Engraver
  29 {
  30
  31   TRANSLATOR_DECLARATIONS (Instrument_switch_engraver);
  32 protected:
  33   Grob *text_;
  34   SCM cue_name_;
  35
  36   void stop_translation_time_step ();
  37   void process_music ();
  38
  39   virtual void derived_mark () const;
  40 };
  41
  42 void
  43 Instrument_switch_engraver::derived_mark () const
  44 {
  45   scm_gc_mark (cue_name_);
  46 }
  47
  48 Instrument_switch_engraver::Instrument_switch_engraver ()
  49 {
  50   cue_name_ = SCM_EOL;
  51   text_ = 0;
  52 }
  53
  54 /*
  55   TODO: should use an event.
  56  */
  57 void
  58 Instrument_switch_engraver::process_music ()
  59 {
  60   SCM cue_text = get_property ("instrumentCueName");
  61
  62   if (!scm_is_eq (cue_name_, cue_text))
  63     {
  64       if (Text_interface::is_markup (cue_text))
  65         {
  66           text_ = make_item ("InstrumentSwitch", SCM_EOL);
  67           text_->set_property ("text", cue_text);
  68         }
  69       cue_name_ = cue_text;
  70     }
  71 }
  72
  73 void
  74 Instrument_switch_engraver::stop_translation_time_step ()
  75 {
  76   text_ = 0;
  77 }
  78
  79 ADD_TRANSLATOR (Instrument_switch_engraver,
  80                 /* doc */
  81                 "Create a cue text for taking instrument.",
  82
  83                 /* create */
  84                 "InstrumentSwitch ",
  85
  86                 /* read */
  87                 "instrumentCueName ",
  88
  89                 /* write */
  90                 ""
  91                 );