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--2008 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "engraver.hh"
  10 #include "international.hh"
  11 #include "spanner.hh"
  12 #include "stream-event.hh"
  13 #include "warn.hh"
  14
  15 #include "translator.icc"
  16
  17 class Staff_symbol_engraver : public Engraver
  18 {
  19 public:
  20   TRANSLATOR_DECLARATIONS (Staff_symbol_engraver);
  21
  22 protected:
  23   Drul_array<Stream_event *> span_events_;
  24   Spanner *span_;
  25   Spanner *finished_span_;
  26   bool first_start_;
  27
  28 protected:
  29   virtual void start_spanner ();
  30   virtual void stop_spanner ();
  31
  32   void stop_translation_timestep ();
  33   virtual ~Staff_symbol_engraver ();
  34   DECLARE_ACKNOWLEDGER (grob);
  35   DECLARE_TRANSLATOR_LISTENER (staff_span);
  36   virtual void finalize ();
  37   void process_music ();
  38 };
  39
  40 Staff_symbol_engraver::~Staff_symbol_engraver ()
  41 {
  42   assert (!span_);
  43 }
  44
  45 Staff_symbol_engraver::Staff_symbol_engraver ()
  46 {
  47   finished_span_ = 0;
  48   first_start_ = true;
  49   span_ = 0;
  50   span_events_[LEFT] = 0;
  51   span_events_[RIGHT] = 0;
  52 }
  53
  54 IMPLEMENT_TRANSLATOR_LISTENER (Staff_symbol_engraver, staff_span);
  55 void
  56 Staff_symbol_engraver::listen_staff_span (Stream_event *ev)
  57 {
  58   Direction d = to_dir (ev->get_property ("span-direction"));
  59   if (d)
  60     ASSIGN_EVENT_ONCE (span_events_[d], ev);
  61   else
  62     programming_error (_ ("staff-span event has no direction"));
  63 }
  64
  65 void
  66 Staff_symbol_engraver::process_music ()
  67 {
  68   if (span_events_[STOP])
  69     {
  70       finished_span_ = span_;
  71       span_ = 0;
  72       if (first_start_)
  73         first_start_ = false;
  74     }
  75
  76   if (span_events_[START]
  77       || (first_start_ && !span_events_[STOP]))
  78     start_spanner ();
  79 }
  80
  81 void
  82 Staff_symbol_engraver::start_spanner ()
  83 {
  84   if (!span_)
  85     {
  86       span_ = make_spanner ("StaffSymbol", SCM_EOL);
  87       span_->set_bound (LEFT,
  88                         unsmob_grob (get_property ("currentCommandColumn")));
  89     }
  90 }
  91
  92 void
  93 Staff_symbol_engraver::stop_spanner ()
  94 {
  95   if (!finished_span_)
  96     return;
  97
  98   if (!finished_span_->get_bound (RIGHT))
  99     finished_span_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
 100
 101   announce_end_grob (finished_span_,
 102                      span_events_[STOP]
 103                      ? span_events_[STOP]->self_scm ()
 104                      : SCM_EOL);
 105
 106   finished_span_ = 0;
 107 }
 108
 109 void
 110 Staff_symbol_engraver::stop_translation_timestep ()
 111 {
 112   if ((span_events_[START] || first_start_)
 113       && span_)
 114     {
 115       first_start_ = false;
 116     }
 117
 118   span_events_[START] = 0;
 119   span_events_[STOP] = 0;
 120   stop_spanner ();
 121 }
 122
 123 void
 124 Staff_symbol_engraver::finalize ()
 125 {
 126   finished_span_ = span_;
 127   span_ = 0;
 128   stop_spanner ();
 129 }
 130
 131 /*
 132   Todo: staff-symbol-referencer iface.
 133 */
 134 void
 135 Staff_symbol_engraver::acknowledge_grob (Grob_info s)
 136 {
 137   /*
 138     Perhaps should try to take SeparationItem as bound of the staff
 139     symbol?
 140   */
 141   if (span_ || finished_span_)
 142     {
 143       Spanner *my = span_ ? span_ : finished_span_;
 144       s.grob ()->set_object ("staff-symbol", my->self_scm ());
 145     }
 146 }
 147
 148 ADD_ACKNOWLEDGER (Staff_symbol_engraver, grob);
 149
 150 ADD_TRANSLATOR (Staff_symbol_engraver,
 151                 /* doc */
 152                 "Create the constellation of five (default) staff lines.",
 153
 154                 /* create */
 155                 "StaffSymbol ",
 156
 157                 /* read */
 158                 "",
 159
 160                 /* write */
 161                 ""
 162                 );