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--2005 Glen Prideaux <glenprideaux@iname.com>,
   7   Han-Wen Nienhuys <hanwen@cs.uu.nl>,
   8   Jan Nieuwenhuizen <janneke@gnu.org>
   9 */
  10
  11 #include "context.hh"
  12 #include "engraver.hh"
  13 #include "pointer-group-interface.hh"
  14 #include "item.hh"
  15 #include "lyric-extender.hh"
  16 #include "note-head.hh"
  17 #include "warn.hh"
  18
  19 void completize_extender (Spanner *sp);
  20
  21 class Extender_engraver : public Engraver
  22 {
  23   Music *ev_;
  24   Spanner *extender_;
  25   Spanner *pending_extender_;
  26
  27 public:
  28   TRANSLATOR_DECLARATIONS (Extender_engraver);
  29
  30 protected:
  31   DECLARE_ACKNOWLEDGER (lyric_syllable);
  32   virtual void finalize ();
  33   virtual bool try_music (Music *);
  34   void stop_translation_timestep ();
  35   void process_music ();
  36 };
  37
  38 Extender_engraver::Extender_engraver ()
  39 {
  40   extender_ = 0;
  41   pending_extender_ = 0;
  42   ev_ = 0;
  43 }
  44
  45 bool
  46 Extender_engraver::try_music (Music *r)
  47 {
  48   if (!ev_)
  49     {
  50       ev_ = r;
  51       return true;
  52     }
  53   return false;
  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         {
 119           sp->set_bound (RIGHT, heads.top());
 120         }
 121     }
 122 }
 123
 124 void
 125 Extender_engraver::finalize ()
 126 {
 127   if (extender_)
 128     {
 129       completize_extender (extender_);
 130
 131       if (!extender_->get_bound (RIGHT))
 132         extender_->warning (_ ("unterminated extender"));
 133       extender_ = 0;
 134     }
 135
 136   if (pending_extender_)
 137     {
 138       completize_extender (pending_extender_);
 139
 140       if (!pending_extender_->get_bound (RIGHT))
 141         pending_extender_->warning (_ ("unterminated extender"));
 142       pending_extender_ = 0;
 143     }
 144 }
 145
 146 #include "translator.icc"
 147
 148 ADD_ACKNOWLEDGER (Extender_engraver,lyric_syllable);
 149 ADD_TRANSLATOR (Extender_engraver,
 150                 /* descr */ "Create lyric extenders",
 151                 /* creats*/ "LyricExtender",
 152                 /* accepts */ "extender-event",
 153                 /* reads */ "",
 154                 /* write */ "");