lily/staff-symbol-engraver.cc

   1 /*
   2   staff-symbol-engraver.cc -- implement Staff_symbol_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "staff-symbol-engraver.hh"
  10 #include "spanner.hh"
  11
  12 Staff_symbol_engraver::~Staff_symbol_engraver ()
  13 {
  14   assert (!span_);
  15 }
  16
  17 Staff_symbol_engraver::Staff_symbol_engraver ()
  18 {
  19   finished_span_ = 0;
  20   first_start_ = true;
  21   span_ = 0;
  22   span_events_[LEFT] = 0;
  23   span_events_[RIGHT] = 0;
  24 }
  25
  26 bool
  27 Staff_symbol_engraver::try_music (Music *music)
  28 {
  29   Direction d = to_dir (music->get_property ("span-direction"));
  30   if (d)
  31     {
  32       span_events_[d] = music;
  33       return true;
  34     }
  35
  36   return false;
  37 }
  38
  39 void
  40 Staff_symbol_engraver::process_music ()
  41 {
  42   if (span_events_[STOP])
  43     {
  44       finished_span_ = span_;
  45       span_ = 0;
  46       if (first_start_)
  47         first_start_ = false;
  48     }
  49
  50   if (span_events_[START]
  51       || (first_start_ && !span_events_[STOP]))
  52     start_spanner ();
  53 }
  54
  55 void
  56 Staff_symbol_engraver::start_spanner ()
  57 {
  58   if (!span_)
  59     span_ = make_spanner ("StaffSymbol", SCM_EOL);
  60 }
  61
  62 void
  63 Staff_symbol_engraver::stop_spanner ()
  64 {
  65   if (finished_span_ && !finished_span_->get_bound (RIGHT))
  66     finished_span_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
  67   finished_span_ = 0;
  68 }
  69
  70 void
  71 Staff_symbol_engraver::stop_translation_timestep ()
  72 {
  73   if ((span_events_[START] || first_start_)
  74       && span_
  75       && !span_->get_bound (LEFT))
  76     {
  77       span_->set_bound (LEFT, unsmob_grob (get_property ("currentCommandColumn")));
  78       first_start_ = false;
  79     }
  80
  81   span_events_[START] = 0;
  82   span_events_[STOP] = 0;
  83   stop_spanner ();
  84 }
  85
  86 void
  87 Staff_symbol_engraver::finalize ()
  88 {
  89   finished_span_ = span_;
  90   span_ = 0;
  91   stop_spanner ();
  92 }
  93
  94 /*
  95   Todo: staff-symbol-referencer iface.
  96 */
  97 void
  98 Staff_symbol_engraver::acknowledge_grob (Grob_info s)
  99 {
 100   /*
 101     Perhaps should try to take SeparationItem as bound of the staff
 102     symbol?
 103   */
 104   if (span_ || finished_span_)
 105     {
 106       Spanner *my = span_ ? span_ : finished_span_;
 107       s.grob ()->set_object ("staff-symbol", my->self_scm ());
 108     }
 109 }
 110
 111 #include "translator.icc"
 112 ADD_ACKNOWLEDGER (Staff_symbol_engraver, grob);
 113 ADD_TRANSLATOR (Staff_symbol_engraver,
 114                 /* doc */ "Create the constellation of five (default) "
 115                 "staff lines.",
 116                 /* create */ "StaffSymbol",
 117                 /* accept */ "staff-span-event",
 118                 /* read */ "",
 119                 /* write */ "");