lily/ledger-line-engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2004--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 "pointer-group-interface.hh"
  21 #include "spanner.hh"
  22 #include "engraver.hh"
  23 #include "staff-symbol.hh"
  24
  25 class Ledger_line_engraver : public Engraver
  26 {
  27   Spanner *span_;
  28   vector<Grob*> ledgered_grobs_;
  29
  30 public:
  31   TRANSLATOR_DECLARATIONS (Ledger_line_engraver);
  32
  33 protected:
  34   virtual void finalize ();
  35   void process_music ();
  36
  37   DECLARE_ACKNOWLEDGER (ledgered);
  38   DECLARE_ACKNOWLEDGER (staff_symbol);
  39
  40   void start_spanner ();
  41   void stop_spanner ();
  42   void stop_translation_timestep ();
  43 };
  44
  45 Ledger_line_engraver::Ledger_line_engraver ()
  46 {
  47   span_ = 0;
  48 }
  49
  50 void
  51 Ledger_line_engraver::start_spanner ()
  52 {
  53   assert (!span_);
  54
  55   span_ = make_spanner ("LedgerLineSpanner", SCM_EOL);
  56   span_->set_bound (LEFT, unsmob_grob (get_property ("currentCommandColumn")));
  57 }
  58
  59 void
  60 Ledger_line_engraver::stop_translation_timestep ()
  61 {
  62   if (span_)
  63     {
  64       for (vsize i = 0; i < ledgered_grobs_.size (); i++)
  65         {
  66           if (!to_boolean (ledgered_grobs_[i]->get_property ("no-ledgers")))
  67             Pointer_group_interface::add_grob (span_,
  68                                                ly_symbol2scm ("note-heads"),
  69                                                ledgered_grobs_[i]);
  70         }
  71     }
  72
  73   ledgered_grobs_.clear ();
  74 }
  75
  76 void
  77 Ledger_line_engraver::process_music ()
  78 {
  79   /*
  80     Need to do this, otherwise the first note might miss ledgers.
  81   */
  82   if (!span_)
  83     start_spanner ();
  84 }
  85
  86 void
  87 Ledger_line_engraver::finalize ()
  88 {
  89   stop_spanner ();
  90 }
  91
  92 void
  93 Ledger_line_engraver::stop_spanner ()
  94 {
  95   if (span_)
  96     {
  97       span_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
  98       Pointer_group_interface::set_ordered (span_, ly_symbol2scm ("elements"), false);
  99       span_ = 0;
 100     }
 101 }
 102
 103 void
 104 Ledger_line_engraver::acknowledge_staff_symbol (Grob_info s)
 105 {
 106   Spanner *sym = dynamic_cast<Spanner *> (s.grob ());
 107
 108   if (!span_
 109       || (span_->get_bound (LEFT) != sym->get_bound (LEFT)))
 110     {
 111       stop_spanner ();
 112       start_spanner ();
 113     }
 114 }
 115
 116 void
 117 Ledger_line_engraver::acknowledge_ledgered (Grob_info s)
 118 {
 119   ledgered_grobs_.push_back (s.grob ());
 120 }
 121
 122 #include "translator.icc"
 123
 124 ADD_ACKNOWLEDGER (Ledger_line_engraver, ledgered);
 125 ADD_ACKNOWLEDGER (Ledger_line_engraver, staff_symbol);
 126 ADD_TRANSLATOR (Ledger_line_engraver,
 127                 /* doc */
 128                 "Create the spanner to draw ledger lines, and notices"
 129                 " objects that need ledger lines.",
 130
 131                 /* create */
 132                 "LedgerLineSpanner ",
 133
 134                 /* read */
 135                 "",
 136
 137                 /* write */
 138                 ""
 139                 );