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--2001 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           && gh_pair_p (gh_cdr (c)))
  64         {
  65           if (gh_cadr (c) ==  SCM_BOOL_F)
  66             end = true;
  67           else
  68             start_str_ = gh_cadr (c);
  69         }
  70
  71       cs = gh_cdr (cs);
  72     }
  73
  74   if (volta_span_p_)
  75     {
  76       SCM l (get_property ("voltaSpannerDuration"));
  77       Moment now = now_mom ();
  78
  79       bool early_stop = unsmob_moment (l)
  80         && *unsmob_moment (l) <= now - started_mom_;
  81
  82       end = end || early_stop;
  83     }
  84
  85
  86   if (end && !volta_span_p_)
  87     {
  88       warning (_ ("No volta spanner to end")); // fixme: be more verbose.
  89     }
  90   else if (end)
  91     {
  92       end_volta_span_p_ = volta_span_p_;
  93       volta_span_p_ =0;
  94
  95       /*
  96         maybe do typeset_grob () directly?
  97       */
  98
  99       if (!gh_string_p (start_str_))
 100         end_volta_span_p_->set_grob_property ("last-volta", SCM_BOOL_T);
 101     }
 102
 103   if (gh_string_p (start_str_) && volta_span_p_)
 104     {
 105       warning (_ ("Already have a volta spanner.  Stopping that one prematurely."));
 106
 107       if (end_volta_span_p_)
 108         {
 109           warning (_ ("Also have a stopped spanner.  Giving up."));
 110           return ;
 111         }
 112
 113       end_volta_span_p_ = volta_span_p_;
 114       volta_span_p_ = 0;
 115     }
 116 }
 117
 118 /*
 119   this could just as well be done in process_music (), but what the hack.
 120  */
 121 void
 122 Volta_engraver::create_grobs ()
 123 {
 124   if (!volta_span_p_ && gh_string_p (start_str_))
 125     {
 126       started_mom_ = now_mom () ;
 127
 128       volta_span_p_ = new Spanner (get_property ("VoltaBracket"));
 129       Volta_spanner::set_interface (volta_span_p_);
 130       announce_grob (volta_span_p_,0);
 131       volta_span_p_->set_grob_property ("text", start_str_);
 132     }
 133 }
 134
 135 void
 136 Volta_engraver::acknowledge_grob (Grob_info i)
 137 {
 138   if (Item* item = dynamic_cast<Item*> (i.elem_l_))
 139     {
 140       if (Note_column::has_interface (item))
 141         {
 142           if (volta_span_p_)
 143             Volta_spanner::add_column (volta_span_p_,item);
 144           if (end_volta_span_p_)
 145             Volta_spanner::add_column (end_volta_span_p_,item);
 146         }
 147       if (Bar::has_interface (item))
 148         {
 149           if (volta_span_p_)
 150             Volta_spanner::add_bar (volta_span_p_, item);
 151           if (end_volta_span_p_)
 152             Volta_spanner::add_bar (end_volta_span_p_ , item);
 153         }
 154     }
 155 }
 156
 157 void
 158 Volta_engraver::finalize ()
 159 {
 160   if (volta_span_p_)
 161     {
 162       typeset_grob (volta_span_p_);
 163     }
 164   if (end_volta_span_p_)
 165     {
 166       typeset_grob (end_volta_span_p_);
 167     }
 168 }
 169
 170
 171
 172 void
 173 Volta_engraver::stop_translation_timestep ()
 174 {
 175   if (end_volta_span_p_)
 176     {
 177       Side_position_interface::add_staff_support (end_volta_span_p_);
 178
 179       typeset_grob (end_volta_span_p_);
 180       end_volta_span_p_ =0;
 181     }
 182 }
 183
 184 /*
 185   TODO: should attach volta to paper-column if no bar is found.
 186  */