lily/lyric-engraver.cc

   1 /*
   2   lyric-engraver.cc -- implement Lyric_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7   Jan Nieuwenhuizen <janneke@gnu.org>
   8 */
   9
  10 #include "engraver.hh"
  11 #include "event.hh"
  12 #include "item.hh"
  13 #include "context.hh"
  14 #include "font-metric.hh"
  15 #include "note-head.hh"
  16
  17 /**
  18    Generate texts for lyric syllables.  We only do one lyric at a time.
  19    Multiple copies of this engraver should be used to do multiple voices.
  20  */
  21 class Lyric_engraver : public Engraver
  22 {
  23 protected:
  24   virtual void stop_translation_timestep ();
  25   virtual bool try_music (Music *);
  26   virtual void process_music ();
  27
  28 public:
  29   TRANSLATOR_DECLARATIONS (Lyric_engraver);
  30 private:
  31   Music * event_;
  32   Item* text_;
  33
  34   Context* get_voice_context ();
  35 };
  36
  37 Lyric_engraver::Lyric_engraver ()
  38 {
  39   text_ =0;
  40   event_ =0;
  41 }
  42
  43 bool
  44 Lyric_engraver::try_music (Music*r)
  45 {
  46   if (r->is_mus_type ("lyric-event"))
  47     {
  48       if (event_)
  49         return false;
  50       event_ =r;
  51       return true;
  52     }
  53   return false;
  54 }
  55
  56 void
  57 Lyric_engraver::process_music ()
  58 {
  59   if (event_)
  60     {
  61       text_=  make_item ("LyricText");
  62
  63       text_->set_property ("text", event_->get_property ("text"));
  64       announce_grob (text_, event_->self_scm ());
  65     }
  66 }
  67
  68
  69 Context*
  70 get_voice_to_lyrics (Context *lyrics)
  71 {
  72   SCM avc = lyrics->get_property ("associatedVoiceContext");
  73   if  (Context *c = unsmob_context (avc))
  74     return c;
  75
  76   SCM voice = lyrics->get_property ("associatedVoice");
  77   String nm = lyrics->id_string_;
  78
  79   if (ly_string_p (voice))
  80     nm = ly_scm2string (voice);
  81   else
  82     {
  83       int idx = nm.index_last ('-');
  84       if (idx >= 0)
  85         nm = nm.left_string (idx);
  86     }
  87
  88   Context *c =  lyrics->find_context_below (ly_symbol2scm ("Voice"), nm);
  89
  90   if (c)
  91     return c;
  92
  93   return lyrics->find_context_below (ly_symbol2scm ("Voice"), "");
  94 }
  95
  96 Grob *
  97 get_current_note_head (Context * voice)
  98 {
  99   for (SCM s = voice->get_property ("busyGrobs");
 100        ly_pair_p (s); s = ly_cdr (s))
 101     {
 102       Item*g = dynamic_cast<Item*> (unsmob_grob (ly_cdar (s)));
 103
 104       if (g && !g->get_column ()
 105           && Note_head::has_interface (g))
 106         return g;
 107     }
 108
 109   return 0;
 110 }
 111
 112 void
 113 Lyric_engraver::stop_translation_timestep ()
 114 {
 115   if (text_)
 116     {
 117       Context * voice = get_voice_to_lyrics (daddy_context_);
 118
 119       if (voice)
 120         {
 121           Grob *head = get_current_note_head (voice);
 122
 123           if (head)
 124             {
 125               text_->set_parent (head, X_AXIS);
 126               if (melisma_busy (voice))
 127                 text_->set_property ("self-alignment-X", scm_int2num (LEFT));
 128             }
 129         }
 130
 131       typeset_grob (text_);
 132       text_ =0;
 133     }
 134   event_ =0;
 135 }
 136
 137
 138 ENTER_DESCRIPTION (Lyric_engraver,
 139 /* descr */       "",
 140 /* creats*/       "",
 141 /* accepts */     "lyric-event",
 142 /* acks  */      "",
 143 /* reads */       "",
 144 /* write */       "");