lily/instrument-switch-engraver.cc

   1 /*
   2   instrument-switch-engraver.cc -- implement
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2006--2009 Han-Wen Nienhuys <hanwen@lilypond.org>
   7
   8 */
   9
  10 #include "engraver.hh"
  11 #include "item.hh"
  12 #include "text-interface.hh"
  13 #include "translator.icc"
  14
  15
  16 class Instrument_switch_engraver : public Engraver
  17 {
  18
  19   TRANSLATOR_DECLARATIONS (Instrument_switch_engraver);
  20 protected:
  21   Grob *text_;
  22   SCM cue_name_;
  23
  24   void stop_translation_time_step ();
  25   void process_music ();
  26 };
  27
  28
  29 Instrument_switch_engraver::Instrument_switch_engraver ()
  30 {
  31   cue_name_ = SCM_EOL;
  32   text_ = 0;
  33 }
  34
  35 /*
  36   TODO: should use an event.
  37  */
  38 void
  39 Instrument_switch_engraver::process_music ()
  40 {
  41   SCM cue_text = get_property ("instrumentCueName");
  42
  43   if (!scm_is_eq (cue_name_, cue_text))
  44     {
  45       if (Text_interface::is_markup (cue_text))
  46 //       if (!scm_is_null (cue_text))
  47         {
  48           text_ = make_item ("InstrumentSwitch", SCM_EOL);
  49           text_->set_property ("text", cue_text);
  50         }
  51       cue_name_ = cue_text;
  52     }
  53 }
  54
  55 void
  56 Instrument_switch_engraver::stop_translation_time_step ()
  57 {
  58   text_ = 0;
  59 }
  60
  61 ADD_TRANSLATOR (Instrument_switch_engraver,
  62                 /* doc */
  63                 "Create a cue text for taking instrument.",
  64
  65                 /* create */
  66                 "InstrumentSwitch ",
  67
  68                 /* read */
  69                 "instrumentCueName ",
  70
  71                 /* write */
  72                 ""
  73                 );