lily/volta-engraver.cc

   1 /*
   2   volta-engraver.cc -- implement Volta_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "engraver.hh"
  10
  11 #include "axis-group-interface.hh"
  12 #include "bar-line.hh"
  13 #include "context.hh"
  14 #include "grob-array.hh"
  15 #include "international.hh"
  16 #include "note-column.hh"
  17 #include "item.hh"
  18 #include "side-position-interface.hh"
  19 #include "staff-symbol.hh"
  20 #include "text-interface.hh"
  21 #include "volta-bracket.hh"
  22 #include "warn.hh"
  23
  24 #include "translator.icc"
  25
  26 /*
  27   Create Volta spanners, by reading repeatCommands  property, usually
  28   set by Volta_repeat_iterator.
  29 */
  30 class Volta_engraver : public Engraver
  31 {
  32 public:
  33   TRANSLATOR_DECLARATIONS (Volta_engraver);
  34 protected:
  35
  36   DECLARE_ACKNOWLEDGER (bar_line);
  37
  38   virtual void derived_mark () const;
  39   void stop_translation_timestep ();
  40   void process_music ();
  41
  42   Moment started_mom_;
  43   Spanner *volta_bracket_;
  44   Spanner *end_volta_bracket_;
  45   Spanner *volta_spanner_;
  46   SCM start_string_;
  47 };
  48
  49 void
  50 Volta_engraver::derived_mark () const
  51 {
  52   scm_gc_mark (start_string_);
  53 }
  54
  55 Volta_engraver::Volta_engraver ()
  56 {
  57   start_string_ = SCM_EOL;
  58   volta_bracket_ = 0;
  59   end_volta_bracket_ = 0;
  60   volta_spanner_ = 0;
  61 }
  62
  63 void
  64 Volta_engraver::process_music ()
  65 {
  66   SCM cs = get_property ("repeatCommands");
  67
  68   bool end = false;
  69   start_string_ = SCM_EOL;
  70   while (scm_is_pair (cs))
  71     {
  72       SCM c = scm_car (cs);
  73
  74       if (scm_is_pair (c)
  75           && scm_car (c) == ly_symbol2scm ("volta")
  76           && scm_is_pair (scm_cdr (c)))
  77         {
  78           if (scm_cadr (c) == SCM_BOOL_F)
  79             end = true;
  80           else
  81             start_string_ = scm_cadr (c);
  82         }
  83
  84       cs = scm_cdr (cs);
  85     }
  86
  87   if (volta_bracket_)
  88     {
  89       SCM l (get_property ("voltaSpannerDuration"));
  90       Moment now = now_mom ();
  91
  92       bool early_stop = unsmob_moment (l)
  93         && *unsmob_moment (l) <= now - started_mom_;
  94
  95       end = end || early_stop;
  96     }
  97
  98   if (end && !volta_bracket_)
  99     /* fixme: be more verbose.  */
 100     warning (_ ("cannot end volta spanner"));
 101   else if (end)
 102     {
 103       end_volta_bracket_ = volta_bracket_;
 104       volta_bracket_ = 0;
 105     }
 106
 107   if (volta_bracket_
 108       && (scm_is_string (start_string_) || scm_is_pair (start_string_)))
 109     {
 110       warning (_ ("already have a volta spanner, ending that one prematurely"));
 111
 112       if (end_volta_bracket_)
 113         {
 114           warning (_ ("also already have an ended spanner"));
 115           warning (_ ("giving up"));
 116           return;
 117         }
 118
 119       end_volta_bracket_ = volta_bracket_;
 120       volta_bracket_ = 0;
 121     }
 122
 123   if (!volta_bracket_
 124       && Text_interface::is_markup (start_string_))
 125     {
 126       started_mom_ = now_mom ();
 127
 128       volta_bracket_ = make_spanner ("VoltaBracket", SCM_EOL);
 129
 130       volta_bracket_->set_property ("text", start_string_);
 131
 132       if (!volta_spanner_)
 133         volta_spanner_ = make_spanner ("VoltaBracketSpanner", SCM_EOL);
 134
 135       Axis_group_interface::add_element (volta_spanner_, volta_bracket_);
 136     }
 137 }
 138
 139 void
 140 Volta_engraver::acknowledge_bar_line (Grob_info i)
 141 {
 142   if (volta_bracket_)
 143     Volta_bracket_interface::add_bar (volta_bracket_, i.item ());
 144   if (end_volta_bracket_)
 145     Volta_bracket_interface::add_bar (end_volta_bracket_, i.item ());
 146
 147   if (volta_spanner_)
 148     Side_position_interface::add_support (volta_spanner_, i.grob ());
 149 }
 150
 151 void
 152 Volta_engraver::stop_translation_timestep ()
 153 {
 154   Grob *cc = unsmob_grob (get_property ("currentCommandColumn"));
 155   Item *ci = dynamic_cast<Item *> (cc);
 156
 157   if (end_volta_bracket_ && !end_volta_bracket_->get_bound (RIGHT))
 158     end_volta_bracket_->set_bound (RIGHT, ci);
 159
 160   if (volta_spanner_ && end_volta_bracket_)
 161     volta_spanner_->set_bound (RIGHT, end_volta_bracket_->get_bound (RIGHT));
 162
 163   if (end_volta_bracket_ && !volta_bracket_)
 164     {
 165       for (SCM s = get_property ("stavesFound"); scm_is_pair (s); s = scm_cdr (s))
 166         Side_position_interface::add_support (volta_spanner_, unsmob_grob (scm_car (s)));
 167       volta_spanner_ = 0;
 168     }
 169
 170   end_volta_bracket_ = 0;
 171
 172   if (volta_bracket_ && !volta_bracket_->get_bound (LEFT))
 173     volta_bracket_->set_bound (LEFT, ci);
 174
 175   if (volta_spanner_ && volta_bracket_ && !volta_spanner_->get_bound (LEFT))
 176     volta_spanner_->set_bound (LEFT, volta_bracket_->get_bound (LEFT));
 177 }
 178
 179 /*
 180   TODO: should attach volta to paper-column if no bar is found.
 181 */
 182 ADD_ACKNOWLEDGER (Volta_engraver, bar_line);
 183 ADD_TRANSLATOR (Volta_engraver,
 184                 /* doc */
 185                 "Make volta brackets.",
 186
 187                 /* create */
 188                 "VoltaBracket "
 189                 "VoltaBracketSpanner ",
 190
 191                 /* read */
 192                 "repeatCommands "
 193                 "voltaSpannerDuration "
 194                 "stavesFound ",
 195
 196                 /* write */
 197                 ""
 198                 );