lily/staff-symbol-engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2010 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "engraver.hh"
  21 #include "international.hh"
  22 #include "spanner.hh"
  23 #include "stream-event.hh"
  24 #include "warn.hh"
  25
  26 #include "translator.icc"
  27
  28 class Staff_symbol_engraver : public Engraver
  29 {
  30 public:
  31   TRANSLATOR_DECLARATIONS (Staff_symbol_engraver);
  32
  33 protected:
  34   Drul_array<Stream_event *> span_events_;
  35   Spanner *span_;
  36   Spanner *finished_span_;
  37   bool first_start_;
  38
  39 protected:
  40   virtual void start_spanner ();
  41   virtual void stop_spanner ();
  42
  43   void stop_translation_timestep ();
  44   virtual ~Staff_symbol_engraver ();
  45   DECLARE_ACKNOWLEDGER (grob);
  46   DECLARE_TRANSLATOR_LISTENER (staff_span);
  47   virtual void finalize ();
  48   void process_music ();
  49 };
  50
  51 Staff_symbol_engraver::~Staff_symbol_engraver ()
  52 {
  53   assert (!span_);
  54 }
  55
  56 Staff_symbol_engraver::Staff_symbol_engraver ()
  57 {
  58   finished_span_ = 0;
  59   first_start_ = true;
  60   span_ = 0;
  61   span_events_[LEFT] = 0;
  62   span_events_[RIGHT] = 0;
  63 }
  64
  65 IMPLEMENT_TRANSLATOR_LISTENER (Staff_symbol_engraver, staff_span);
  66 void
  67 Staff_symbol_engraver::listen_staff_span (Stream_event *ev)
  68 {
  69   Direction d = to_dir (ev->get_property ("span-direction"));
  70   if (d)
  71     ASSIGN_EVENT_ONCE (span_events_[d], ev);
  72   else
  73     programming_error (_ ("staff-span event has no direction"));
  74 }
  75
  76 void
  77 Staff_symbol_engraver::process_music ()
  78 {
  79   if (span_events_[STOP])
  80     {
  81       finished_span_ = span_;
  82       span_ = 0;
  83       if (first_start_)
  84         first_start_ = false;
  85     }
  86
  87   if (span_events_[START]
  88       || (first_start_ && !span_events_[STOP]))
  89     start_spanner ();
  90 }
  91
  92 void
  93 Staff_symbol_engraver::start_spanner ()
  94 {
  95   if (!span_)
  96     {
  97       span_ = make_spanner ("StaffSymbol", SCM_EOL);
  98       span_->set_bound (LEFT,
  99                         unsmob_grob (get_property ("currentCommandColumn")));
 100     }
 101 }
 102
 103 void
 104 Staff_symbol_engraver::stop_spanner ()
 105 {
 106   if (!finished_span_)
 107     return;
 108
 109   if (!finished_span_->get_bound (RIGHT))
 110     finished_span_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
 111
 112   announce_end_grob (finished_span_,
 113                      span_events_[STOP]
 114                      ? span_events_[STOP]->self_scm ()
 115                      : SCM_EOL);
 116
 117   finished_span_ = 0;
 118 }
 119
 120 void
 121 Staff_symbol_engraver::stop_translation_timestep ()
 122 {
 123   if ((span_events_[START] || first_start_)
 124       && span_)
 125     {
 126       first_start_ = false;
 127     }
 128
 129   span_events_[START] = 0;
 130   span_events_[STOP] = 0;
 131   stop_spanner ();
 132 }
 133
 134 void
 135 Staff_symbol_engraver::finalize ()
 136 {
 137   finished_span_ = span_;
 138   span_ = 0;
 139   stop_spanner ();
 140 }
 141
 142 /*
 143   Todo: staff-symbol-referencer iface.
 144 */
 145 void
 146 Staff_symbol_engraver::acknowledge_grob (Grob_info s)
 147 {
 148   /*
 149     Perhaps should try to take SeparationItem as bound of the staff
 150     symbol?
 151   */
 152   if (span_ || finished_span_)
 153     {
 154       Spanner *my = span_ ? span_ : finished_span_;
 155       s.grob ()->set_object ("staff-symbol", my->self_scm ());
 156     }
 157 }
 158
 159 ADD_ACKNOWLEDGER (Staff_symbol_engraver, grob);
 160
 161 ADD_TRANSLATOR (Staff_symbol_engraver,
 162                 /* doc */
 163                 "Create the constellation of five (default) staff lines.",
 164
 165                 /* create */
 166                 "StaffSymbol ",
 167
 168                 /* read */
 169                 "",
 170
 171                 /* write */
 172                 ""
 173                 );