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--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "engraver.hh"
  11 #include "translator-group.hh"
  12 #include "volta-bracket.hh"
  13 #include "item.hh"
  14 #include "note-column.hh"
  15 #include "bar-line.hh"
  16 #include "side-position-interface.hh"
  17 #include "warn.hh"
  18 #include "staff-symbol.hh"
  19
  20 /*
  21   Create Volta spanners, by reading repeatCommands  property, usually
  22   set by Unfolded_repeat_iterator.
  23  */
  24 class Volta_engraver : public Engraver
  25 {
  26 public:
  27   TRANSLATOR_DECLARATIONS(Volta_engraver);
  28 protected:
  29
  30   virtual void acknowledge_grob (Grob_info);
  31   virtual void finalize ();
  32   virtual void stop_translation_timestep ();
  33   virtual void process_music ();
  34   virtual void process_acknowledged_grobs ();
  35
  36   Moment started_mom_;
  37   Spanner *volta_span_;
  38   Spanner *end_volta_span_;
  39   SCM staff_;
  40   SCM start_string_;
  41 };
  42
  43 Volta_engraver::Volta_engraver ()
  44 {
  45   staff_ = SCM_EOL;
  46   volta_span_ = 0;
  47   end_volta_span_ = 0;
  48 }
  49
  50
  51 void
  52 Volta_engraver::process_music ()
  53 {
  54   if (unsmob_grob (staff_)
  55       && !to_boolean (get_property ("voltaOnThisStaff")))
  56     {
  57       /*
  58         TODO: this does weird things when you open a piece with a
  59         volta spanner.
  60
  61        */
  62       SCM staffs = get_property ("stavesFound");
  63
  64       /*
  65         only put a volta on the top staff.
  66
  67         May be this is a bit convoluted, and we should have a single
  68         volta engraver in score context or somesuch.
  69
  70       */
  71       if (!gh_pair_p (staffs))
  72         programming_error ("Huh? Volta engraver can't find staffs?");
  73       else if (ly_car (scm_last_pair (staffs)) != staff_)
  74         return ;
  75     }
  76
  77
  78   SCM cs = get_property ("repeatCommands");
  79
  80   bool  end = false;
  81   start_string_ = SCM_EOL;
  82   while (gh_pair_p (cs))
  83     {
  84       SCM c = ly_car (cs);
  85
  86       if (gh_pair_p (c)
  87           && ly_car (c) == ly_symbol2scm ("volta")
  88           && gh_pair_p (ly_cdr (c)))
  89         {
  90           if (ly_cadr (c) ==  SCM_BOOL_F)
  91             end = true;
  92           else
  93             start_string_ = ly_cadr (c);
  94         }
  95
  96       cs = ly_cdr (cs);
  97     }
  98
  99   if (volta_span_)
 100     {
 101       SCM l (get_property ("voltaSpannerDuration"));
 102       Moment now = now_mom ();
 103
 104       bool early_stop = unsmob_moment (l)
 105         && *unsmob_moment (l) <= now - started_mom_;
 106
 107       end = end || early_stop;
 108     }
 109
 110
 111   if (end && !volta_span_)
 112     {
 113       warning (_ ("No volta spanner to end")); // fixme: be more verbose.
 114     }
 115   else if (end)
 116     {
 117       end_volta_span_ = volta_span_;
 118       volta_span_ =0;
 119     }
 120
 121   if (volta_span_ &&
 122       (gh_string_p (start_string_) || gh_pair_p (start_string_)))
 123     {
 124       warning (_ ("Already have a volta spanner.  Stopping that one prematurely."));
 125
 126       if (end_volta_span_)
 127         {
 128           warning (_ ("Also have a stopped spanner.  Giving up."));
 129           return ;
 130         }
 131
 132       end_volta_span_ = volta_span_;
 133       volta_span_ = 0;
 134     }
 135 }
 136
 137 /*
 138   this could just as well be done in process_music (), but what the hack.
 139  */
 140 void
 141 Volta_engraver::process_acknowledged_grobs ()
 142 {
 143   if (!volta_span_ &&
 144       (gh_string_p (start_string_) || gh_pair_p (start_string_)))
 145     {
 146       started_mom_ = now_mom () ;
 147
 148       volta_span_ = new Spanner (get_property ("VoltaBracket"));
 149
 150       announce_grob (volta_span_, SCM_EOL);
 151       volta_span_->set_grob_property ("text", start_string_);
 152     }
 153 }
 154
 155 void
 156 Volta_engraver::acknowledge_grob (Grob_info i)
 157 {
 158   if (Item* item = dynamic_cast<Item*> (i.grob_))
 159     {
 160       if (Note_column::has_interface (item))
 161         {
 162           if (volta_span_)
 163             Volta_bracket_interface::add_column (volta_span_,item);
 164         }
 165       if (Bar_line::has_interface (item))
 166         {
 167           if (volta_span_)
 168             Volta_bracket_interface::add_bar (volta_span_, item);
 169           if (end_volta_span_)
 170             Volta_bracket_interface::add_bar (end_volta_span_ , item);
 171         }
 172     }
 173   else if (Staff_symbol::has_interface (i.grob_))
 174     {
 175       /*
 176         We only want to know about a single staff: then we add to the
 177         support.  */
 178       if (staff_ != SCM_EOL)
 179         staff_ = SCM_UNDEFINED;
 180
 181       if (staff_ != SCM_UNDEFINED)
 182         staff_ = i.grob_->self_scm();
 183     }
 184 }
 185
 186 void
 187 Volta_engraver::finalize ()
 188 {
 189   if (volta_span_)
 190     {
 191       typeset_grob (volta_span_);
 192     }
 193   if (end_volta_span_)
 194     {
 195       typeset_grob (end_volta_span_);
 196     }
 197 }
 198
 199
 200
 201 void
 202 Volta_engraver::stop_translation_timestep ()
 203 {
 204   if (end_volta_span_)
 205     {
 206       typeset_grob (end_volta_span_);
 207       end_volta_span_ =0;
 208     }
 209 }
 210
 211 /*
 212   TODO: should attach volta to paper-column if no bar is found.
 213  */
 214
 215 ENTER_DESCRIPTION(Volta_engraver,
 216 /* descr */       "Make volta brackets",
 217 /* creats*/       "VoltaBracket",
 218 /* accepts */     "",
 219 /* acks  */       "bar-line-interface staff-symbol-interface note-column-interface",
 220 /* reads */       "repeatCommands voltaSpannerDuration stavesFound",
 221 /* write */       "");