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--2002 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "engraver.hh"
  11 #include "translator-group.hh"
  12 #include "volta-spanner.hh"
  13 #include "item.hh"
  14 #include "note-column.hh"
  15 #include "bar-line.hh"
  16 #include "side-position-interface.hh"
  17 #include "staff-symbol.hh"
  18
  19 /*
  20   Create Volta spanners, by reading repeatCommands  property, usually
  21   set by Unfolded_repeat_iterator.
  22  */
  23 class Volta_engraver : public Engraver
  24 {
  25 public:
  26   TRANSLATOR_DECLARATIONS(Volta_engraver);
  27 protected:
  28
  29   virtual void acknowledge_grob (Grob_info);
  30   virtual void finalize ();
  31   virtual void stop_translation_timestep ();
  32   virtual void process_music ();
  33   virtual void create_grobs ();
  34
  35   Moment started_mom_;
  36   Spanner *volta_span_p_;
  37   Spanner *end_volta_span_p_;
  38   SCM staff_;
  39   SCM start_str_;
  40 };
  41
  42 Volta_engraver::Volta_engraver ()
  43 {
  44   staff_ = SCM_EOL;
  45   volta_span_p_ = 0;
  46   end_volta_span_p_ = 0;
  47 }
  48
  49
  50 void
  51 Volta_engraver::process_music ()
  52 {
  53   if (unsmob_grob (staff_))
  54     {
  55       /*
  56         TODO: this does weird things when you open a piece with a
  57         volta spanner.
  58
  59        */
  60       SCM staffs = get_property ("stavesFound");
  61
  62       /*
  63         only put a volta on the top staff.
  64
  65         May be this is a bit convoluted, and we should have a single
  66         volta engraver in score context or somesuch.
  67
  68       */
  69       if (ly_car (scm_last_pair (staffs)) != staff_)
  70         return ;
  71     }
  72
  73
  74   SCM cs = get_property ("repeatCommands");
  75
  76   bool  end = false;
  77   start_str_ = SCM_EOL;
  78   while (gh_pair_p (cs))
  79     {
  80       SCM c = ly_car (cs);
  81
  82       if (gh_pair_p (c) && ly_car (c) == ly_symbol2scm ("volta")
  83           && gh_pair_p (ly_cdr (c)))
  84         {
  85           if (ly_cadr (c) ==  SCM_BOOL_F)
  86             end = true;
  87           else
  88             start_str_ = ly_cadr (c);
  89         }
  90
  91       cs = ly_cdr (cs);
  92     }
  93
  94   if (volta_span_p_)
  95     {
  96       SCM l (get_property ("voltaSpannerDuration"));
  97       Moment now = now_mom ();
  98
  99       bool early_stop = unsmob_moment (l)
 100         && *unsmob_moment (l) <= now - started_mom_;
 101
 102       end = end || early_stop;
 103     }
 104
 105
 106   if (end && !volta_span_p_)
 107     {
 108       warning (_ ("No volta spanner to end")); // fixme: be more verbose.
 109     }
 110   else if (end)
 111     {
 112       end_volta_span_p_ = volta_span_p_;
 113       volta_span_p_ =0;
 114     }
 115
 116   if (gh_string_p (start_str_) && volta_span_p_)
 117     {
 118       warning (_ ("Already have a volta spanner.  Stopping that one prematurely."));
 119
 120       if (end_volta_span_p_)
 121         {
 122           warning (_ ("Also have a stopped spanner.  Giving up."));
 123           return ;
 124         }
 125
 126       end_volta_span_p_ = volta_span_p_;
 127       volta_span_p_ = 0;
 128     }
 129 }
 130
 131 /*
 132   this could just as well be done in process_music (), but what the hack.
 133  */
 134 void
 135 Volta_engraver::create_grobs ()
 136 {
 137   if (!volta_span_p_ && gh_string_p (start_str_))
 138     {
 139       started_mom_ = now_mom () ;
 140
 141       volta_span_p_ = new Spanner (get_property ("VoltaBracket"));
 142       Volta_spanner::set_interface (volta_span_p_);
 143       announce_grob (volta_span_p_, SCM_EOL);
 144       volta_span_p_->set_grob_property ("text", start_str_);
 145     }
 146 }
 147
 148 void
 149 Volta_engraver::acknowledge_grob (Grob_info i)
 150 {
 151   if (Item* item = dynamic_cast<Item*> (i.grob_l_))
 152     {
 153       if (Note_column::has_interface (item))
 154         {
 155           if (volta_span_p_)
 156             Volta_spanner::add_column (volta_span_p_,item);
 157         }
 158       if (Bar_line::has_interface (item))
 159         {
 160           if (volta_span_p_)
 161             Volta_spanner::add_bar (volta_span_p_, item);
 162           if (end_volta_span_p_)
 163             Volta_spanner::add_bar (end_volta_span_p_ , item);
 164         }
 165     }
 166   else if (Staff_symbol::has_interface (i.grob_l_))
 167     {
 168       /*
 169         We only want to know about a single staff: then we add to the
 170         support.  */
 171       if (staff_ != SCM_EOL)
 172         staff_ = SCM_UNDEFINED;
 173
 174       if (staff_ != SCM_UNDEFINED)
 175         staff_ = i.grob_l_->self_scm();
 176     }
 177 }
 178
 179 void
 180 Volta_engraver::finalize ()
 181 {
 182   if (volta_span_p_)
 183     {
 184       typeset_grob (volta_span_p_);
 185     }
 186   if (end_volta_span_p_)
 187     {
 188       typeset_grob (end_volta_span_p_);
 189     }
 190 }
 191
 192
 193
 194 void
 195 Volta_engraver::stop_translation_timestep ()
 196 {
 197   if (end_volta_span_p_)
 198     {
 199       typeset_grob (end_volta_span_p_);
 200       end_volta_span_p_ =0;
 201     }
 202 }
 203
 204 /*
 205   TODO: should attach volta to paper-column if no bar is found.
 206  */
 207
 208 ENTER_DESCRIPTION(Volta_engraver,
 209 /* descr */       "Make volta brackets",
 210 /* creats*/       "VoltaBracket",
 211 /* acks  */       "bar-line-interface staff-symbol-interface note-column-interface",
 212 /* reads */       "repeatCommands voltaSpannerDuration stavesFound",
 213 /* write */       "");