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--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7   Jan Nieuwenhuizen <janneke@gnu.org>
   8 */
   9
  10 #include "context.hh"
  11 #include "engraver.hh"
  12 #include "item.hh"
  13 #include "note-head.hh"
  14 #include "stream-event.hh"
  15 #include "international.hh"
  16
  17 #include "translator.icc"
  18
  19 /**
  20    Generate texts for lyric syllables.  We only do one lyric at a time.
  21    Multiple copies of this engraver should be used to do multiple voices.
  22 */
  23 class Lyric_engraver : public Engraver
  24 {
  25 protected:
  26   void stop_translation_timestep ();
  27   void process_music ();
  28   DECLARE_TRANSLATOR_LISTENER (lyric);
  29
  30 public:
  31   TRANSLATOR_DECLARATIONS (Lyric_engraver);
  32
  33 private:
  34   Stream_event *event_;
  35   Item *text_;
  36   Item *last_text_;
  37
  38   Context *get_voice_context ();
  39 };
  40
  41 Lyric_engraver::Lyric_engraver ()
  42 {
  43   text_ = 0;
  44   last_text_ = 0;
  45   event_ = 0;
  46 }
  47
  48 IMPLEMENT_TRANSLATOR_LISTENER (Lyric_engraver, lyric);
  49 void
  50 Lyric_engraver::listen_lyric (Stream_event *ev)
  51 {
  52   ASSIGN_EVENT_ONCE (event_, ev);
  53 }
  54
  55 void
  56 Lyric_engraver::process_music ()
  57 {
  58   if (event_)
  59     {
  60       SCM text = event_->get_property ("text");
  61
  62       if (ly_is_equal (text, scm_from_locale_string (" ")))
  63         {
  64           if (last_text_)
  65             last_text_->set_property ("self-alignment-X", scm_from_int (LEFT));
  66         }
  67       /*
  68         "Empty" LyricText objects are needed to allow the Extender_engraver to
  69         distinguish between the end of a lyrics block and manual melismata.
  70       */
  71       text_ = make_item ("LyricText", event_->self_scm ());
  72     }
  73 }
  74
  75 Context *
  76 get_voice_to_lyrics (Context *lyrics)
  77 {
  78   SCM avc = lyrics->get_property ("associatedVoiceContext");
  79   if (Context *c = unsmob_context (avc))
  80     return c;
  81
  82   SCM voice_name = lyrics->get_property ("associatedVoice");
  83   string nm = lyrics->id_string ();
  84
  85   if (scm_is_string (voice_name))
  86     nm = ly_scm2string (voice_name);
  87   else if (nm == "")
  88     return 0;
  89   else
  90     {
  91       ssize idx = nm.rfind ('-');
  92       if (idx != NPOS)
  93         nm = nm.substr (0, idx);
  94     }
  95
  96   Context *parent = lyrics;
  97   Context *voice = 0;
  98   while (parent && !voice)
  99     {
 100       voice = find_context_below (parent, ly_symbol2scm ("Voice"), nm);
 101       parent = parent->get_parent_context ();
 102     }
 103
 104   if (voice)
 105     return voice;
 106
 107   parent = lyrics;
 108   voice = 0;
 109   while (parent && !voice)
 110     {
 111       voice = find_context_below (parent, ly_symbol2scm ("Voice"), "");
 112       parent = parent->get_parent_context ();
 113     }
 114
 115   return voice;
 116 }
 117
 118 Grob *
 119 get_current_note_head (Context *voice)
 120 {
 121   Moment now = voice->now_mom ();
 122   for (SCM s = voice->get_property ("busyGrobs");
 123        scm_is_pair (s); s = scm_cdr (s))
 124     {
 125       Grob *g = unsmob_grob (scm_cdar (s));;
 126       Moment *end_mom = unsmob_moment (scm_caar (s));
 127       if (!end_mom || !g)
 128         {
 129           programming_error ("busyGrobs invalid");
 130           continue;
 131         }
 132
 133       if (end_mom->main_part_ > now.main_part_
 134           && dynamic_cast<Item *> (g)
 135           && Note_head::has_interface (g))
 136         return g;
 137     }
 138
 139   return 0;
 140 }
 141
 142 void
 143 Lyric_engraver::stop_translation_timestep ()
 144 {
 145   if (text_)
 146     {
 147       Context *voice = get_voice_to_lyrics (context ());
 148
 149       if (voice)
 150         {
 151           Grob *head = get_current_note_head (voice);
 152
 153           if (head)
 154             {
 155               text_->set_parent (head, X_AXIS);
 156               if (melisma_busy (voice)
 157                   && !to_boolean (get_property ("ignoreMelismata")))
 158                 text_->set_property ("self-alignment-X",
 159                                      get_property("lyricMelismaAlignment"));
 160             }
 161           else
 162             {
 163               text_->warning (_ ("Lyric syllable does not have note. Use \\lyricsto or associatedVoice."));
 164               text_->set_property ("X-offset", scm_from_int (0));
 165             }
 166         }
 167
 168       last_text_ = text_;
 169       text_ = 0;
 170     }
 171   event_ = 0;
 172 }
 173
 174 ADD_TRANSLATOR (Lyric_engraver,
 175                 /* doc */
 176                 "Engrave text for lyrics.",
 177
 178                 /* create */
 179                 "LyricText ",
 180
 181                 /* read */
 182                 "ignoreMelismata "
 183                 "lyricMelismaAlignment ",
 184
 185                 /* write */
 186                 ""
 187                 );