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 "warn.hh"
  10 #include "spanner.hh"
  11 #include "rhythmic-head.hh"
  12 #include "engraver.hh"
  13
  14 /**
  15    Create line-spanner grobs for glissandi lines that connect note
  16    heads.
  17 */
  18 class Glissando_engraver : public Engraver
  19 {
  20 public:
  21   TRANSLATOR_DECLARATIONS (Glissando_engraver);
  22
  23 protected:
  24   DECLARE_ACKNOWLEDGER (rhythmic_head);
  25   virtual void finalize ();
  26   void stop_translation_timestep ();
  27   virtual bool try_music (Music *);
  28   void process_music ();
  29 private:
  30   Spanner *line_;
  31   Spanner *last_line_;
  32   Music *event_;
  33 };
  34
  35 Glissando_engraver::Glissando_engraver ()
  36 {
  37   last_line_ = line_ = 0;
  38   event_ = 0;
  39 }
  40
  41 bool
  42 Glissando_engraver::try_music (Music *m)
  43 {
  44   if (!event_)
  45     {
  46       event_ = m;
  47       return true;
  48     }
  49   return false;
  50 }
  51
  52 void
  53 Glissando_engraver::process_music ()
  54 {
  55   if (event_)
  56     line_ = make_spanner ("Glissando", event_->self_scm ());
  57 }
  58
  59 void
  60 Glissando_engraver::acknowledge_rhythmic_head (Grob_info info)
  61 {
  62   Grob *g = info.grob ();
  63   if (line_)
  64     line_->set_bound (LEFT, g);
  65
  66   if (last_line_)
  67     last_line_->set_bound (RIGHT, g);
  68 }
  69
  70 void
  71 Glissando_engraver::stop_translation_timestep ()
  72 {
  73   if (last_line_ && last_line_->get_bound (RIGHT))
  74     last_line_ = 0;
  75   if (line_)
  76     {
  77       if (last_line_)
  78         programming_error ("overwriting glissando");
  79       last_line_ = line_;
  80     }
  81   line_ = 0;
  82   event_ = 0;
  83 }
  84
  85 void
  86 Glissando_engraver::finalize ()
  87 {
  88   if (line_)
  89     {
  90       String msg = _ ("unterminated glissando");
  91
  92       if (event_)
  93         event_->origin ()->warning (msg);
  94       else
  95         warning (msg);
  96
  97       line_->suicide ();
  98       line_ = 0;
  99     }
 100 }
 101
 102 #include "translator.icc"
 103
 104 ADD_ACKNOWLEDGER (Glissando_engraver, rhythmic_head);
 105 ADD_TRANSLATOR (Glissando_engraver,
 106                 /* doc */ "Engrave a glissandi",
 107                 /* create */ "Glissando",
 108                 /* accept */ "glissando-event",
 109                 /* read */ "followVoice",
 110                 /* write */ "");