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     {
  60       span_ = make_spanner ("StaffSymbol", SCM_EOL);
  61       span_->set_bound (LEFT,
  62                         unsmob_grob (get_property ("currentCommandColumn")));
  63     }
  64 }
  65
  66 void
  67 Staff_symbol_engraver::stop_spanner ()
  68 {
  69   if (finished_span_ && !finished_span_->get_bound (RIGHT))
  70     finished_span_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
  71   finished_span_ = 0;
  72 }
  73
  74 void
  75 Staff_symbol_engraver::stop_translation_timestep ()
  76 {
  77   if ((span_events_[START] || first_start_)
  78       && span_)
  79     {
  80       first_start_ = false;
  81     }
  82
  83   span_events_[START] = 0;
  84   span_events_[STOP] = 0;
  85   stop_spanner ();
  86 }
  87
  88 void
  89 Staff_symbol_engraver::finalize ()
  90 {
  91   finished_span_ = span_;
  92   span_ = 0;
  93   stop_spanner ();
  94 }
  95
  96 /*
  97   Todo: staff-symbol-referencer iface.
  98 */
  99 void
 100 Staff_symbol_engraver::acknowledge_grob (Grob_info s)
 101 {
 102   /*
 103     Perhaps should try to take SeparationItem as bound of the staff
 104     symbol?
 105   */
 106   if (span_ || finished_span_)
 107     {
 108       Spanner *my = span_ ? span_ : finished_span_;
 109       s.grob ()->set_object ("staff-symbol", my->self_scm ());
 110     }
 111 }
 112
 113 #include "translator.icc"
 114
 115 ADD_ACKNOWLEDGER (Staff_symbol_engraver, grob);
 116
 117 ADD_TRANSLATOR (Staff_symbol_engraver,
 118                 /* doc */ "Create the constellation of five (default) "
 119                 "staff lines.",
 120                 /* create */ "StaffSymbol",
 121                 /* accept */ "staff-span-event",
 122                 /* read */ "",
 123                 /* write */ "");