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--2003 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 "paper-def.hh"
  14 #include "font-metric.hh"
  15 #include "side-position-interface.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_acknowledged_grobs ();
  27   virtual void start_translation_timestep ();
  28
  29 public:
  30   TRANSLATOR_DECLARATIONS(Lyric_engraver);
  31 private:
  32   Music * req_;
  33   Item* text_;
  34 };
  35
  36
  37
  38
  39 Lyric_engraver::Lyric_engraver ()
  40 {
  41   text_ =0;
  42   req_ =0;
  43 }
  44
  45 bool
  46 Lyric_engraver::try_music (Music*r)
  47 {
  48   if (r->is_mus_type ("lyric-event"))
  49     {
  50       if (req_)
  51         return false;
  52       req_ =r;
  53       return true;
  54     }
  55   return false;
  56 }
  57
  58 void
  59 Lyric_engraver::process_acknowledged_grobs ()
  60 {
  61   if (req_)
  62     {
  63       text_=  new Item (get_property ("LyricText"));
  64
  65       text_->set_grob_property ("text", req_->get_mus_property ("text"));
  66
  67       /*
  68         We can't reach the notehead where we're centered from here. So
  69         we kludge.
  70
  71  (UGH UGH, pulled amount of space out of thin air)
  72       */
  73
  74       text_->translate_axis (0.66, X_AXIS);
  75
  76       announce_grob(text_, req_->self_scm());
  77       req_ = 0;
  78     }
  79 }
  80
  81 void
  82 Lyric_engraver::stop_translation_timestep ()
  83 {
  84   if (text_)
  85     {
  86       typeset_grob (text_);
  87       text_ =0;
  88     }
  89 }
  90
  91 void
  92 Lyric_engraver::start_translation_timestep ()
  93 {
  94   req_ =0;
  95 }
  96
  97
  98 ENTER_DESCRIPTION(Lyric_engraver,
  99 /* descr */       "",
 100 /* creats*/       "",
 101 /* accepts */     "lyric-event",
 102 /* acks  */      "",
 103 /* reads */       "",
 104 /* write */       "");