lily/glissando-engraver.cc

   1 /*
   2   note-head-line-engraver.cc -- implement Note_head_line_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000--2006 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include "engraver.hh"
  10 #include "international.hh"
  11 #include "rhythmic-head.hh"
  12 #include "spanner.hh"
  13 #include "stream-event.hh"
  14 #include "warn.hh"
  15
  16 #include "translator.icc"
  17
  18 /**
  19    Create line-spanner grobs for glissandi lines that connect note
  20    heads.
  21 */
  22 class Glissando_engraver : public Engraver
  23 {
  24 public:
  25   TRANSLATOR_DECLARATIONS (Glissando_engraver);
  26
  27 protected:
  28   DECLARE_TRANSLATOR_LISTENER (glissando);
  29   DECLARE_ACKNOWLEDGER (rhythmic_head);
  30   virtual void finalize ();
  31
  32   void stop_translation_timestep ();
  33   void process_music ();
  34 private:
  35   Spanner *line_;
  36   Spanner *last_line_;
  37   Stream_event *event_;
  38 };
  39
  40 Glissando_engraver::Glissando_engraver ()
  41 {
  42   last_line_ = line_ = 0;
  43   event_ = 0;
  44 }
  45
  46 IMPLEMENT_TRANSLATOR_LISTENER (Glissando_engraver, glissando);
  47 void
  48 Glissando_engraver::listen_glissando (Stream_event *ev)
  49 {
  50   ASSIGN_EVENT_ONCE (event_, ev);
  51 }
  52
  53 void
  54 Glissando_engraver::process_music ()
  55 {
  56   if (event_)
  57     line_ = make_spanner ("Glissando", event_->self_scm ());
  58 }
  59
  60 void
  61 Glissando_engraver::acknowledge_rhythmic_head (Grob_info info)
  62 {
  63   Grob *g = info.grob ();
  64   if (line_)
  65     line_->set_bound (LEFT, g);
  66
  67   if (last_line_)
  68     last_line_->set_bound (RIGHT, g);
  69 }
  70
  71 void
  72 Glissando_engraver::stop_translation_timestep ()
  73 {
  74   if (last_line_ && last_line_->get_bound (RIGHT))
  75     last_line_ = 0;
  76   if (line_)
  77     {
  78       if (last_line_)
  79         programming_error ("overwriting glissando");
  80       last_line_ = line_;
  81     }
  82   line_ = 0;
  83   event_ = 0;
  84 }
  85
  86 void
  87 Glissando_engraver::finalize ()
  88 {
  89   if (line_)
  90     {
  91       string msg = _ ("unterminated glissando");
  92
  93       if (event_)
  94         event_->origin ()->warning (msg);
  95       else
  96         warning (msg);
  97
  98       line_->suicide ();
  99       line_ = 0;
 100     }
 101 }
 102
 103 ADD_ACKNOWLEDGER (Glissando_engraver, rhythmic_head);
 104 ADD_TRANSLATOR (Glissando_engraver,
 105                 /* doc */ "Engrave a glissandi",
 106                 /* create */ "Glissando",
 107                 /* accept */ "glissando-event",
 108                 /* read */ "followVoice",
 109                 /* write */ "");