lily/melody-engraver.cc

   1 /*
   2   melody-engraver.cc -- implement Melody_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9
  10 #include "engraver.hh"
  11
  12 #include "item.hh"
  13 #include "melody-spanner.hh"
  14 #include "pointer-group-interface.hh"
  15
  16 class Melody_engraver : public Engraver
  17 {
  18   Grob *melody_item_;
  19   Grob *stem_;
  20 protected:
  21
  22   DECLARE_ACKNOWLEDGER (stem);
  23   DECLARE_ACKNOWLEDGER (slur);
  24   TRANSLATOR_DECLARATIONS (Melody_engraver);
  25   void stop_translation_timestep ();
  26   void process_music ();
  27 };
  28
  29
  30 Melody_engraver::Melody_engraver ()
  31 {
  32   stem_ = 0;
  33   melody_item_ = 0;
  34 }
  35
  36 void
  37 Melody_engraver::process_music ()
  38 {
  39   if (scm_is_string (get_property ("whichBar")))
  40     melody_item_ = 0;
  41 }
  42
  43 void
  44 Melody_engraver::stop_translation_timestep ()
  45 {
  46   if (stem_
  47       && !is_direction (stem_->get_property_data ("neutral-direction")))
  48     {
  49       extract_grob_set (stem_, "rests", rests);
  50       if (rests.size ())
  51         melody_item_ = 0;
  52       else
  53         {
  54           if (!melody_item_)
  55             melody_item_ = make_item ("MelodyItem", stem_->self_scm ());
  56
  57           Melody_spanner::add_stem (melody_item_, stem_);
  58         }
  59     }
  60   stem_ = 0;
  61 }
  62
  63
  64 void
  65 Melody_engraver::acknowledge_slur (Grob_info /* info */)
  66 {
  67   melody_item_ = 0;
  68 }
  69
  70
  71 void
  72 Melody_engraver::acknowledge_stem (Grob_info info)
  73 {
  74   stem_ = info.grob ();
  75 }
  76
  77
  78
  79 #include "translator.icc"
  80
  81 ADD_ACKNOWLEDGER (Melody_engraver, stem);
  82 ADD_ACKNOWLEDGER (Melody_engraver, slur);
  83
  84 ADD_TRANSLATOR (Melody_engraver,
  85                 /* doc */
  86                 "Create information for context dependent typesetting"
  87                 " decisions.",
  88
  89                 /* create */
  90                 "MelodyItem ",
  91
  92                 /* read */
  93                 "",
  94
  95                 /* write */
  96                 ""
  97                 );
  98