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",event_->self_scm ());
  62
  63       text_->set_property ("text", event_->get_property ("text"));
  64     }
  65 }
  66
  67
  68 Context*
  69 get_voice_to_lyrics (Context *lyrics)
  70 {
  71   SCM avc = lyrics->get_property ("associatedVoiceContext");
  72   if  (Context *c = unsmob_context (avc))
  73     return c;
  74
  75   SCM voice_name = lyrics->get_property ("associatedVoice");
  76   String nm = lyrics->id_string ();
  77
  78   if (ly_c_string_p (voice_name))
  79     nm = ly_scm2string (voice_name);
  80   else
  81     {
  82       int idx = nm.index_last ('-');
  83       if (idx >= 0)
  84         nm = nm.left_string (idx);
  85     }
  86
  87   Context *parent = lyrics;
  88   Context *voice = 0;
  89   while (parent && !voice)
  90     {
  91       voice = find_context_below (parent, ly_symbol2scm ("Voice"), nm);
  92       parent = parent->get_parent_context ();
  93     }
  94
  95   if (voice)
  96     return voice;
  97
  98   parent = lyrics;
  99   voice = 0;
 100   while (parent && !voice)
 101     {
 102       voice = find_context_below (parent, ly_symbol2scm ("Voice"), "");
 103       parent = parent->get_parent_context ();
 104     }
 105
 106   return voice;
 107 }
 108
 109 Grob *
 110 get_current_note_head (Context * voice)
 111 {
 112   for (SCM s = voice->get_property ("busyGrobs");
 113        ly_c_pair_p (s); s = ly_cdr (s))
 114     {
 115       Item*g = dynamic_cast<Item*> (unsmob_grob (ly_cdar (s)));
 116
 117       if (g && !g->get_column ()
 118           && Note_head::has_interface (g))
 119         return g;
 120     }
 121
 122   return 0;
 123 }
 124
 125 void
 126 Lyric_engraver::stop_translation_timestep ()
 127 {
 128   if (text_)
 129     {
 130       Context * voice = get_voice_to_lyrics (context ());
 131
 132       if (voice)
 133         {
 134           Grob *head = get_current_note_head (voice);
 135
 136           if (head)
 137             {
 138               text_->set_parent (head, X_AXIS);
 139               if (melisma_busy (voice))
 140                 text_->set_property ("self-alignment-X", scm_int2num (LEFT));
 141             }
 142         }
 143
 144       text_ =0;
 145     }
 146   event_ =0;
 147 }
 148
 149
 150 ENTER_DESCRIPTION (Lyric_engraver,
 151 /* descr */       "",
 152 /* creats*/       "",
 153 /* accepts */     "lyric-event",
 154 /* acks  */      "",
 155 /* reads */       "",
 156 /* write */       "");