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 "warn.hh"
  19
  20 void completize_extender (Spanner *sp);
  21
  22 class Extender_engraver : public Engraver
  23 {
  24   Music *ev_;
  25   Spanner *extender_;
  26   Spanner *pending_extender_;
  27
  28 public:
  29   TRANSLATOR_DECLARATIONS (Extender_engraver);
  30
  31 protected:
  32   DECLARE_ACKNOWLEDGER (lyric_syllable);
  33   virtual void finalize ();
  34   virtual bool try_music (Music *);
  35   void stop_translation_timestep ();
  36   void process_music ();
  37 };
  38
  39 Extender_engraver::Extender_engraver ()
  40 {
  41   extender_ = 0;
  42   pending_extender_ = 0;
  43   ev_ = 0;
  44 }
  45
  46 bool
  47 Extender_engraver::try_music (Music *r)
  48 {
  49   if (!ev_)
  50     {
  51       ev_ = r;
  52       return true;
  53     }
  54   return false;
  55 }
  56
  57 void
  58 Extender_engraver::process_music ()
  59 {
  60   if (ev_)
  61     extender_ = make_spanner ("LyricExtender", ev_->self_scm ());
  62 }
  63
  64 void
  65 Extender_engraver::acknowledge_lyric_syllable (Grob_info i)
  66 {
  67   Item *item = i.item ();
  68   if (extender_)
  69     extender_->set_bound (LEFT, item);
  70
  71   if (pending_extender_)
  72     {
  73       pending_extender_->set_object ("next", item->self_scm ());
  74       completize_extender (pending_extender_);
  75       pending_extender_ = 0;
  76     }
  77 }
  78
  79 void
  80 Extender_engraver::stop_translation_timestep ()
  81 {
  82   if (extender_ || pending_extender_)
  83     {
  84       Context *voice = get_voice_to_lyrics (context ());
  85       Grob *h = voice ? get_current_note_head (voice) : 0;
  86
  87       if (h)
  88         {
  89           if (extender_)
  90             {
  91               Pointer_group_interface::add_grob (extender_,
  92                                                  ly_symbol2scm ("heads"), h);
  93             }
  94
  95           if (pending_extender_)
  96             {
  97               Pointer_group_interface::add_grob (pending_extender_,
  98                                                  ly_symbol2scm ("heads"), h);
  99             }
 100         }
 101
 102       if (extender_)
 103         {
 104           pending_extender_ = extender_;
 105           extender_ = 0;
 106         }
 107     }
 108
 109   ev_ = 0;
 110 }
 111
 112 void
 113 completize_extender (Spanner *sp)
 114 {
 115   if (!sp->get_bound (RIGHT))
 116     {
 117       extract_item_set (sp, "heads", heads);
 118       if (heads.size ())
 119         sp->set_bound (RIGHT, heads.back ());
 120     }
 121 }
 122
 123 void
 124 Extender_engraver::finalize ()
 125 {
 126   if (extender_)
 127     {
 128       completize_extender (extender_);
 129
 130       if (!extender_->get_bound (RIGHT))
 131         extender_->warning (_ ("unterminated extender"));
 132       extender_ = 0;
 133     }
 134
 135   if (pending_extender_)
 136     {
 137       completize_extender (pending_extender_);
 138
 139       if (!pending_extender_->get_bound (RIGHT))
 140         pending_extender_->warning (_ ("unterminated extender"));
 141       pending_extender_ = 0;
 142     }
 143 }
 144
 145 #include "translator.icc"
 146
 147 ADD_ACKNOWLEDGER (Extender_engraver, lyric_syllable);
 148 ADD_TRANSLATOR (Extender_engraver,
 149                 /* doc */ "Create lyric extenders",
 150                 /* create */ "LyricExtender",
 151                 /* accept */ "extender-event",
 152                 /* read */ "",
 153                 /* write */ "");