lily/extender-engraver.cc

   1 /*
   2   extender-engraver.cc -- implement Extender_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1999--2006 Glen Prideaux <glenprideaux@iname.com>,
   7   Han-Wen Nienhuys <hanwen@xs4all.nl>,
   8   Jan Nieuwenhuizen <janneke@gnu.org>
   9 */
  10
  11 #include "context.hh"
  12 #include "engraver.hh"
  13 #include "international.hh"
  14 #include "item.hh"
  15 #include "lyric-extender.hh"
  16 #include "note-head.hh"
  17 #include "pointer-group-interface.hh"
  18 #include "stream-event.hh"
  19 #include "warn.hh"
  20
  21 #include "translator.icc"
  22
  23 void completize_extender (Spanner *sp);
  24
  25 class Extender_engraver : public Engraver
  26 {
  27   Stream_event *ev_;
  28   Spanner *extender_;
  29   Spanner *pending_extender_;
  30
  31 public:
  32   TRANSLATOR_DECLARATIONS (Extender_engraver);
  33
  34 protected:
  35   DECLARE_TRANSLATOR_LISTENER (extender);
  36   DECLARE_ACKNOWLEDGER (lyric_syllable);
  37   virtual void finalize ();
  38   void stop_translation_timestep ();
  39   void process_music ();
  40 };
  41
  42 Extender_engraver::Extender_engraver ()
  43 {
  44   extender_ = 0;
  45   pending_extender_ = 0;
  46   ev_ = 0;
  47 }
  48
  49 IMPLEMENT_TRANSLATOR_LISTENER (Extender_engraver, extender);
  50 void
  51 Extender_engraver::listen_extender (Stream_event *ev)
  52 {
  53   ASSIGN_EVENT_ONCE (ev_, ev);
  54 }
  55
  56 void
  57 Extender_engraver::process_music ()
  58 {
  59   if (ev_)
  60     extender_ = make_spanner ("LyricExtender", ev_->self_scm ());
  61 }
  62
  63 void
  64 Extender_engraver::acknowledge_lyric_syllable (Grob_info i)
  65 {
  66   Item *item = i.item ();
  67   if (extender_)
  68     extender_->set_bound (LEFT, item);
  69
  70   if (pending_extender_)
  71     {
  72       pending_extender_->set_object ("next", item->self_scm ());
  73       completize_extender (pending_extender_);
  74       pending_extender_ = 0;
  75     }
  76 }
  77
  78 void
  79 Extender_engraver::stop_translation_timestep ()
  80 {
  81   if (extender_ || pending_extender_)
  82     {
  83       Context *voice = get_voice_to_lyrics (context ());
  84       Grob *h = voice ? get_current_note_head (voice) : 0;
  85
  86       if (h)
  87         {
  88           if (extender_)
  89             {
  90               Pointer_group_interface::add_grob (extender_,
  91                                                  ly_symbol2scm ("heads"), h);
  92             }
  93
  94           if (pending_extender_)
  95             {
  96               Pointer_group_interface::add_grob (pending_extender_,
  97                                                  ly_symbol2scm ("heads"), h);
  98             }
  99         }
 100
 101       if (extender_)
 102         {
 103           pending_extender_ = extender_;
 104           extender_ = 0;
 105         }
 106     }
 107
 108   ev_ = 0;
 109 }
 110
 111 void
 112 completize_extender (Spanner *sp)
 113 {
 114   if (!sp->get_bound (RIGHT))
 115     {
 116       extract_item_set (sp, "heads", heads);
 117       if (heads.size ())
 118         sp->set_bound (RIGHT, heads.back ());
 119     }
 120 }
 121
 122 void
 123 Extender_engraver::finalize ()
 124 {
 125   if (extender_)
 126     {
 127       completize_extender (extender_);
 128
 129       if (!extender_->get_bound (RIGHT))
 130         extender_->warning (_ ("unterminated extender"));
 131       extender_ = 0;
 132     }
 133
 134   if (pending_extender_)
 135     {
 136       completize_extender (pending_extender_);
 137
 138       if (!pending_extender_->get_bound (RIGHT))
 139         pending_extender_->warning (_ ("unterminated extender"));
 140       pending_extender_ = 0;
 141     }
 142 }
 143
 144 ADD_ACKNOWLEDGER (Extender_engraver, lyric_syllable);
 145 ADD_TRANSLATOR (Extender_engraver,
 146                 /* doc */ "Create lyric extenders",
 147                 /* create */ "LyricExtender",
 148                 /* accept */ "extender-event",
 149                 /* read */ "",
 150                 /* write */ "");