lily/bar-number-engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2011 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 <algorithm> // for reverse
  21
  22 #include "paper-column.hh"
  23 #include "output-def.hh"
  24 #include "side-position-interface.hh"
  25 #include "engraver.hh"
  26 #include "context.hh"
  27 #include "grob-array.hh"
  28 #include "stream-event.hh"
  29
  30 #include "translator.icc"
  31
  32 /*
  33   TODO: detect the top staff (stavesFound), and acknowledge staff-group
  34   system-start-delims. If we find these, and the top staff is in the
  35   staff-group, add padding to the bar number.
  36 */
  37 class Bar_number_engraver : public Engraver
  38 {
  39 protected:
  40   Item *text_;
  41   int alternative_starting_bar_number_;
  42   int alternative_number_;
  43   int alternative_number_increment_;
  44   Stream_event *alternative_event_;
  45
  46 protected:
  47   void stop_translation_timestep ();
  48   DECLARE_TRANSLATOR_LISTENER (alternative);
  49   DECLARE_ACKNOWLEDGER (break_alignment);
  50   void process_music ();
  51   void create_items ();
  52   TRANSLATOR_DECLARATIONS (Bar_number_engraver);
  53 };
  54
  55 IMPLEMENT_TRANSLATOR_LISTENER (Bar_number_engraver, alternative);
  56 void
  57 Bar_number_engraver::listen_alternative (Stream_event *ev)
  58 {
  59   if (alternative_event_)
  60     return;
  61
  62   alternative_event_ = ev;
  63   int current_barnumber = robust_scm2int (get_property ("currentBarNumber"), 0);
  64   Direction alternative_dir = robust_scm2dir (ev->get_property ("alternative-dir"), CENTER);
  65   bool make_alternative = get_property ("alternativeNumberingStyle") == ly_symbol2scm ("numbers")
  66                           || get_property ("alternativeNumberingStyle") == ly_symbol2scm ("numbers-with-letters");
  67   if (make_alternative)
  68     {
  69       /*
  70         if we're starting the first alternative, we set the starting
  71         bar number to the current bar number
  72       */
  73       if (alternative_dir == LEFT)
  74         alternative_starting_bar_number_ = current_barnumber;
  75
  76       /*
  77         if the alternative is not the last one, we send the
  78         current bar number back to the alternative bar number.
  79       */
  80       if (alternative_dir < RIGHT)
  81         current_barnumber = alternative_starting_bar_number_;
  82
  83       context ()->set_property ("currentBarNumber", scm_from_int (current_barnumber));
  84     }
  85 }
  86
  87 int
  88 int_pow (int n, int i)
  89 {
  90   if (i == 1)
  91     return n;
  92   if (i <= 0)
  93     return 1;
  94   return int_pow (n * n, i - 1);
  95 }
  96
  97 void
  98 Bar_number_engraver::process_music ()
  99 {
 100   SCM wb = get_property ("whichBar");
 101
 102   if (scm_is_string (wb))
 103     {
 104       Moment mp (robust_scm2moment (get_property ("measurePosition"), Moment (0)));
 105       if (mp.main_part_ == Rational (0))
 106         {
 107           SCM bn = get_property ("currentBarNumber");
 108           SCM proc = get_property ("barNumberVisibility");
 109           if (scm_is_number (bn) && ly_is_procedure (proc)
 110               && to_boolean (scm_call_1 (proc, bn)))
 111             {
 112               create_items ();
 113               SCM alternative_style = get_property ("alternativeNumberingStyle");
 114               string text_tag = "";
 115               if (alternative_style == ly_symbol2scm ("numbers-with-letters"))
 116                 {
 117                   if (alternative_event_)
 118                     {
 119                       Direction alternative_dir = robust_scm2dir (alternative_event_->get_property ("alternative-dir"), RIGHT);
 120                       switch (alternative_dir)
 121                         {
 122                         case LEFT:
 123                           alternative_number_ = 0;
 124                           break;
 125                         case CENTER:
 126                           break;
 127                         case RIGHT:
 128                           alternative_number_ = INT_MIN;
 129                           break;
 130                         default:
 131                           assert (false);
 132                         }
 133                       alternative_number_ += alternative_number_increment_;
 134
 135                       alternative_number_increment_ = robust_scm2int (alternative_event_->get_property ("alternative-increment"), 1);
 136                     }
 137                   if (alternative_number_ >= 0)
 138                     {
 139                       string alphabet = "abcdefghijklmnopqrstuvwxyz";
 140                       int power = 0;
 141                       int running_sum = 0;
 142                       int scratch = alternative_number_;
 143                       while (running_sum <= alternative_number_)
 144                         {
 145                           power++;
 146                           running_sum += int_pow (26, power);
 147                         }
 148                       scratch += int_pow (26, power) - running_sum;
 149                       for (int i = power; i--;)
 150                         text_tag += alphabet.at ((scratch / int_pow (26, i)) % 26);
 151                     }
 152                 }
 153               // guh.
 154               text_->set_property
 155               ("text",
 156                scm_string_concatenate (scm_list_2 (scm_number_to_string (bn, scm_from_int (10)),
 157                                                    ly_string2scm (text_tag))));
 158             }
 159         }
 160     }
 161 }
 162
 163 Bar_number_engraver::Bar_number_engraver ()
 164 {
 165   text_ = 0;
 166   alternative_starting_bar_number_ = 0;
 167   alternative_number_increment_ = 0;
 168   alternative_number_ = INT_MIN;
 169   alternative_event_ = 0;
 170 }
 171
 172 void
 173 Bar_number_engraver::acknowledge_break_alignment (Grob_info inf)
 174 {
 175   Grob *s = inf.grob ();
 176   if (text_
 177       && dynamic_cast<Item *> (s))
 178     {
 179       text_->set_parent (s, X_AXIS);
 180     }
 181 }
 182
 183 void
 184 Bar_number_engraver::stop_translation_timestep ()
 185 {
 186   alternative_event_ = 0;
 187   if (text_)
 188     {
 189       text_->set_object ("side-support-elements",
 190                          grob_list_to_grob_array (get_property ("stavesFound")));
 191       text_ = 0;
 192     }
 193 }
 194
 195 void
 196 Bar_number_engraver::create_items ()
 197 {
 198   if (text_)
 199     return;
 200
 201   text_ = make_item ("BarNumber", SCM_EOL);
 202 }
 203
 204 ADD_ACKNOWLEDGER (Bar_number_engraver, break_alignment);
 205
 206 ADD_TRANSLATOR (Bar_number_engraver,
 207                 /* doc */
 208                 "A bar number is created whenever @code{measurePosition} is"
 209                 " zero and when there is a bar line (i.e., when"
 210                 " @code{whichBar} is set).  It is put on top of all staves,"
 211                 " and appears only at the left side of the staff.  The staves"
 212                 " are taken from @code{stavesFound}, which is maintained by"
 213                 " @ref{Staff_collecting_engraver}.",
 214
 215                 /* create */
 216                 "BarNumber ",
 217
 218                 /* read */
 219                 "currentBarNumber "
 220                 "whichBar "
 221                 "stavesFound "
 222                 "barNumberVisibility "
 223                 "alternativeNumberingStyle ",
 224
 225                 /* write */
 226                 "currentBarNumber "
 227                );