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--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7   Jan Nieuwenhuizen <janneke@gnu.org>
   8 */
   9
  10 #include "context.hh"
  11 #include "engraver.hh"
  12 #include "font-metric.hh"
  13 #include "item.hh"
  14 #include "multi-measure-rest.hh"
  15 #include "note-head.hh"
  16 #include "rest.hh"
  17
  18 /**
  19    Generate texts for lyric syllables.  We only do one lyric at a time.
  20    Multiple copies of this engraver should be used to do multiple voices.
  21 */
  22 class Lyric_engraver : public Engraver
  23 {
  24 protected:
  25   virtual void stop_translation_timestep ();
  26   virtual bool try_music (Music *);
  27   virtual void process_music ();
  28
  29 public:
  30   TRANSLATOR_DECLARATIONS (Lyric_engraver);
  31
  32 private:
  33   Music *event_;
  34   Item *text_;
  35
  36   Context *get_voice_context ();
  37 };
  38
  39 Lyric_engraver::Lyric_engraver ()
  40 {
  41   text_ = 0;
  42   event_ = 0;
  43 }
  44
  45 bool
  46 Lyric_engraver::try_music (Music *r)
  47 {
  48   if (!event_)
  49     {
  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       text_->set_property ("text", event_->get_property ("text"));
  63     }
  64 }
  65
  66 Context *
  67 get_voice_to_lyrics (Context *lyrics)
  68 {
  69   SCM avc = lyrics->get_property ("associatedVoiceContext");
  70   if (Context *c = unsmob_context (avc))
  71     return c;
  72
  73   SCM voice_name = lyrics->get_property ("associatedVoice");
  74   String nm = lyrics->id_string ();
  75
  76   if (scm_is_string (voice_name))
  77     nm = ly_scm2string (voice_name);
  78   else
  79     {
  80       int idx = nm.index_last ('-');
  81       if (idx >= 0)
  82         nm = nm.left_string (idx);
  83     }
  84
  85   Context *parent = lyrics;
  86   Context *voice = 0;
  87   while (parent && !voice)
  88     {
  89       voice = find_context_below (parent, ly_symbol2scm ("Voice"), nm);
  90       parent = parent->get_parent_context ();
  91     }
  92
  93   if (voice)
  94     return voice;
  95
  96   parent = lyrics;
  97   voice = 0;
  98   while (parent && !voice)
  99     {
 100       voice = find_context_below (parent, ly_symbol2scm ("Voice"), "");
 101       parent = parent->get_parent_context ();
 102     }
 103
 104   return voice;
 105 }
 106
 107 Grob *
 108 get_current_note_head (Context *voice)
 109 {
 110   for (SCM s = voice->get_property ("busyGrobs");
 111        scm_is_pair (s); s = scm_cdr (s))
 112     {
 113       Item *g = dynamic_cast<Item *> (unsmob_grob (scm_cdar (s)));
 114
 115       if (g && !g->get_column ()
 116           && Note_head::has_interface (g))
 117         return g;
 118     }
 119
 120   return 0;
 121 }
 122
 123 void
 124 Lyric_engraver::stop_translation_timestep ()
 125 {
 126   if (text_)
 127     {
 128       Context *voice = get_voice_to_lyrics (context ());
 129
 130       if (voice)
 131         {
 132           Grob *head = get_current_note_head (voice);
 133
 134           if (head)
 135             {
 136               text_->set_parent (head, X_AXIS);
 137               if (melisma_busy (voice))
 138                 text_->set_property ("self-alignment-X", scm_int2num (LEFT));
 139             }
 140         }
 141
 142       text_ = 0;
 143     }
 144   event_ = 0;
 145 }
 146
 147 ADD_TRANSLATOR (Lyric_engraver,
 148                 /* descr */ "",
 149                 /* creats*/ "LyricText",
 150                 /* accepts */ "lyric-event",
 151                 /* acks  */ "",
 152                 /* reads */ "",
 153                 /* write */ "");