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 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.hh"
  16 #include "side-position-interface.hh"
  17
  18 /*
  19   Create Volta spanners, by reading repeatCommands  property, usually
  20   set by Unfolded_repeat_iterator.
  21  */
  22 class Volta_engraver : public Engraver
  23 {
  24 public:
  25   Volta_engraver();
  26   VIRTUAL_COPY_CONS(Translator);
  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
  39   SCM start_str_;
  40 };
  41
  42 ADD_THIS_TRANSLATOR(Volta_engraver);
  43
  44 Volta_engraver::Volta_engraver ()
  45 {
  46   volta_span_p_ = 0;
  47   end_volta_span_p_ = 0;
  48 }
  49
  50
  51 void
  52 Volta_engraver::process_music ()
  53 {
  54   SCM cs = get_property ("repeatCommands");
  55
  56   bool  end = false;
  57   start_str_ = SCM_EOL;
  58   while (gh_pair_p (cs))
  59     {
  60       SCM c = gh_car (cs);
  61
  62       if (gh_pair_p (c) && gh_car (c) == ly_symbol2scm ("volta"))
  63         {
  64           if (gh_cadr (c) ==  SCM_BOOL_F)
  65             end = true;
  66           else
  67             start_str_ = gh_cadr (c);
  68         }
  69
  70       cs = gh_cdr (cs);
  71     }
  72
  73   if (volta_span_p_)
  74     {
  75       SCM l (get_property ("voltaSpannerDuration"));
  76       Moment now = now_mom ();
  77
  78       bool early_stop = unsmob_moment (l)
  79         && *unsmob_moment (l) <= now - started_mom_;
  80
  81       end = end || early_stop;
  82     }
  83
  84
  85   if (end && !volta_span_p_)
  86     {
  87       warning (_("No volta spanner to end")); // fixme: be more verbose.
  88     }
  89   else if (end)
  90     {
  91       end_volta_span_p_ = volta_span_p_;
  92       volta_span_p_ =0;
  93
  94       /*
  95         maybe do typeset_grob () directly?
  96       */
  97
  98       if (!gh_string_p (start_str_))
  99         end_volta_span_p_->set_grob_property ("last-volta", SCM_BOOL_T);
 100     }
 101
 102   if (gh_string_p (start_str_) && volta_span_p_)
 103     {
 104       warning (_ ("Already have a volta spanner.  Stopping that one prematurely."));
 105
 106       if (end_volta_span_p_)
 107         {
 108           warning (_ ("Also have a stopped spanner.  Giving up."));
 109           return ;
 110         }
 111
 112       end_volta_span_p_ = volta_span_p_;
 113       volta_span_p_ = 0;
 114     }
 115 }
 116
 117 /*
 118   this could just as well be done in process_music (), but what the hack.
 119  */
 120 void
 121 Volta_engraver::create_grobs ()
 122 {
 123   if (!volta_span_p_ && gh_string_p (start_str_))
 124     {
 125       started_mom_ = now_mom () ;
 126
 127       volta_span_p_ = new Spanner (get_property ("VoltaBracket"));
 128       Volta_spanner::set_interface (volta_span_p_);
 129       announce_grob (volta_span_p_,0);
 130       volta_span_p_->set_grob_property ("text", start_str_);
 131     }
 132 }
 133
 134 void
 135 Volta_engraver::acknowledge_grob (Grob_info i)
 136 {
 137   if (Item* item = dynamic_cast<Item*> (i.elem_l_))
 138     {
 139       if (Note_column::has_interface (item))
 140         {
 141           if (volta_span_p_)
 142             Volta_spanner::add_column (volta_span_p_,item);
 143           if (end_volta_span_p_)
 144             Volta_spanner::add_column (end_volta_span_p_,item);
 145         }
 146       if (Bar::has_interface (item))
 147         {
 148           if (volta_span_p_)
 149             Volta_spanner::add_bar (volta_span_p_, item);
 150           if (end_volta_span_p_)
 151             Volta_spanner::add_bar(end_volta_span_p_ , item);
 152         }
 153     }
 154 }
 155
 156 void
 157 Volta_engraver::finalize ()
 158 {
 159   if (volta_span_p_)
 160     {
 161       typeset_grob(volta_span_p_);
 162     }
 163   if (end_volta_span_p_)
 164     {
 165       typeset_grob (end_volta_span_p_);
 166     }
 167 }
 168
 169
 170
 171 void
 172 Volta_engraver::stop_translation_timestep ()
 173 {
 174   if (end_volta_span_p_)
 175     {
 176       Side_position::add_staff_support (end_volta_span_p_);
 177
 178       typeset_grob (end_volta_span_p_ );
 179       end_volta_span_p_ =0;
 180     }
 181 }
 182
 183 /*
 184   TODO: should attach volta to paper-column if no bar is found.
 185  */