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--2004 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 "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   virtual void acknowledge_grob (Grob_info);
  32   virtual void finalize ();
  33   virtual bool try_music (Music*);
  34   virtual void stop_translation_timestep ();
  35   virtual void process_music ();
  36 };
  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_grob (Grob_info i)
  66 {
  67   Item *item = dynamic_cast<Item*> (i.grob_);
  68
  69   if (item
  70       && item->internal_has_interface (ly_symbol2scm ("lyric-syllable-interface")))
  71     {
  72       if (extender_)
  73         extender_->set_bound (LEFT, item);
  74
  75       if (pending_extender_)
  76         {
  77           pending_extender_->set_property ("next", item->self_scm ());
  78           completize_extender (pending_extender_);
  79           pending_extender_ = 0;
  80         }
  81     }
  82 }
  83
  84 void
  85 Extender_engraver::stop_translation_timestep ()
  86 {
  87   if (extender_ || pending_extender_)
  88     {
  89       Context *voice = get_voice_to_lyrics (context ());
  90       Grob *h = voice ? get_current_note_head (voice) : 0;
  91
  92       if (h)
  93         {
  94           if (extender_)
  95             {
  96               Pointer_group_interface::add_grob (extender_,
  97                                                  ly_symbol2scm ("heads"), h);
  98             }
  99
 100           if (pending_extender_)
 101             {
 102               Pointer_group_interface::add_grob (pending_extender_,
 103                                                  ly_symbol2scm ("heads"), h);
 104             }
 105         }
 106
 107       if (extender_)
 108         {
 109           pending_extender_ = extender_;
 110           extender_ = 0;
 111         }
 112     }
 113
 114   ev_ = 0;
 115 }
 116
 117 void
 118 completize_extender (Spanner *sp)
 119 {
 120   if (!sp->get_bound (RIGHT))
 121     {
 122       SCM heads = sp->get_property ("heads");
 123       if (scm_is_pair (heads))
 124         {
 125           Item *it = dynamic_cast<Item*> (unsmob_grob (scm_car (heads)));
 126           if (it)
 127             sp->set_bound (RIGHT, it);
 128         }
 129     }
 130 }
 131
 132 void
 133 Extender_engraver::finalize ()
 134 {
 135   if (extender_)
 136     {
 137       completize_extender (extender_);
 138
 139       if (!extender_->get_bound (RIGHT))
 140         extender_->warning (_ ("unterminated extender"));
 141       extender_ = 0;
 142     }
 143
 144   if (pending_extender_)
 145     {
 146       completize_extender (pending_extender_);
 147
 148       if (!pending_extender_->get_bound (RIGHT))
 149         pending_extender_->warning (_ ("unterminated extender"));
 150       pending_extender_ =0;
 151     }
 152 }
 153
 154
 155 ENTER_DESCRIPTION (Extender_engraver,
 156 /* descr */       "Create lyric extenders",
 157 /* creats*/       "LyricExtender",
 158 /* accepts */     "extender-event",
 159 /* acks  */       "lyric-syllable-interface",
 160 /* reads */       "",
 161 /* write */       "");