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--2009 Glen Prideaux <glenprideaux@iname.com>,
   7   Han-Wen Nienhuys <hanwen@xs4all.nl>,
   8   Jan Nieuwenhuizen <janneke@gnu.org>
   9 */
  10 #include "context.hh"
  11 #include "engraver.hh"
  12 #include "international.hh"
  13 #include "item.hh"
  14 #include "lyric-extender.hh"
  15 #include "note-head.hh"
  16 #include "pointer-group-interface.hh"
  17 #include "stream-event.hh"
  18 #include "warn.hh"
  19 #include "spanner.hh"
  20 #include "paper-column.hh"
  21
  22 #include "translator.icc"
  23
  24 void completize_extender (Spanner *sp);
  25
  26 class Extender_engraver : public Engraver
  27 {
  28   Stream_event *ev_;
  29   Spanner *extender_;
  30   Spanner *pending_extender_;
  31   bool current_lyric_is_skip_;
  32
  33 public:
  34   TRANSLATOR_DECLARATIONS (Extender_engraver);
  35
  36 protected:
  37   DECLARE_TRANSLATOR_LISTENER (extender);
  38   DECLARE_ACKNOWLEDGER (lyric_syllable);
  39
  40   virtual void finalize ();
  41
  42   void stop_translation_timestep ();
  43   void process_music ();
  44 };
  45
  46 Extender_engraver::Extender_engraver ()
  47 {
  48   current_lyric_is_skip_ = false;
  49   extender_ = 0;
  50   pending_extender_ = 0;
  51   ev_ = 0;
  52 }
  53
  54 IMPLEMENT_TRANSLATOR_LISTENER (Extender_engraver, extender);
  55 void
  56 Extender_engraver::listen_extender (Stream_event *ev)
  57 {
  58   ASSIGN_EVENT_ONCE (ev_, ev);
  59 }
  60
  61 void
  62 Extender_engraver::process_music ()
  63 {
  64   if (ev_)
  65     extender_ = make_spanner ("LyricExtender", ev_->self_scm ());
  66 }
  67
  68 void
  69 Extender_engraver::acknowledge_lyric_syllable (Grob_info i)
  70 {
  71   Item *item = i.item ();
  72   if (extender_)
  73     extender_->set_bound (LEFT, item);
  74
  75   SCM text = item->get_property ("text");
  76   current_lyric_is_skip_ = ly_is_equal (text, scm_from_locale_string (" "));
  77
  78   if (pending_extender_ && !current_lyric_is_skip_)
  79     {
  80       pending_extender_->set_object ("next", item->self_scm ());
  81       completize_extender (pending_extender_);
  82       pending_extender_ = 0;
  83     }
  84 }
  85
  86 void
  87 Extender_engraver::stop_translation_timestep ()
  88 {
  89   if (extender_ || pending_extender_)
  90     {
  91       Context *voice = get_voice_to_lyrics (context ());
  92       Grob *h = voice ? get_current_note_head (voice) : 0;
  93
  94       if (h)
  95         {
  96           if (extender_)
  97             {
  98               Pointer_group_interface::add_grob (extender_,
  99                                                  ly_symbol2scm ("heads"), h);
 100             }
 101
 102         if (pending_extender_)
 103           {
 104             Pointer_group_interface::add_grob (pending_extender_,
 105                                               ly_symbol2scm ("heads"), h);
 106             /*
 107               The following check addresses the case where the lyrics end before
 108               the associated voice. The current_lyric_is_skip_ check is
 109               necessary to handle manual melismata, which should not result in
 110               extenders being completized. We also need to make sure that we're not
 111               in the middle of a note (happens when this function is called because
 112               of an event in a voice other than our associated one).
 113             */
 114             if (!melisma_busy (voice) && !current_lyric_is_skip_)
 115               {
 116                 Moment now = voice->now_mom ();
 117                 Paper_column *column = (dynamic_cast<Item *> (h))->get_column ();
 118                 Moment *start_mom = column ? unsmob_moment (column->get_property ("when")) : 0;
 119                 if (!column || (start_mom->main_part_ == now.main_part_))
 120                   {
 121                     completize_extender (pending_extender_);
 122                     pending_extender_ = 0;
 123                   }
 124               }
 125             }
 126         }
 127       else
 128         {
 129           if (pending_extender_
 130               && !get_property ("extendersOverRests"))
 131             {
 132               completize_extender (pending_extender_);
 133               pending_extender_ = 0;
 134             }
 135
 136         }
 137       if (extender_)
 138         {
 139           pending_extender_ = extender_;
 140           extender_ = 0;
 141         }
 142     }
 143
 144   ev_ = 0;
 145 }
 146
 147 void
 148 completize_extender (Spanner *sp)
 149 {
 150   if (!sp->get_bound (RIGHT))
 151     {
 152       extract_item_set (sp, "heads", heads);
 153       if (heads.size ())
 154         sp->set_bound (RIGHT, heads.back ());
 155     }
 156 }
 157
 158 void
 159 Extender_engraver::finalize ()
 160 {
 161   if (extender_)
 162     {
 163       completize_extender (extender_);
 164
 165       if (!extender_->get_bound (RIGHT))
 166         extender_->warning (_ ("unterminated extender"));
 167       extender_ = 0;
 168     }
 169
 170   if (pending_extender_)
 171     {
 172       completize_extender (pending_extender_);
 173
 174       if (!pending_extender_->get_bound (RIGHT))
 175         pending_extender_->warning (_ ("unterminated extender"));
 176       pending_extender_ = 0;
 177     }
 178 }
 179
 180 ADD_ACKNOWLEDGER (Extender_engraver, lyric_syllable);
 181 ADD_TRANSLATOR (Extender_engraver,
 182                 /* doc */
 183                 "Create lyric extenders.",
 184
 185                 /* create */
 186                 "LyricExtender ",
 187
 188                 /* read */
 189                 "extendersOverRests ",
 190
 191                 /* write */
 192                 ""
 193                 );