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) && ly_car (c) == ly_symbol2scm ("volta")
  87           && gh_pair_p (ly_cdr (c)))
  88         {
  89           if (ly_cadr (c) ==  SCM_BOOL_F)
  90             end = true;
  91           else
  92             start_string_ = ly_cadr (c);
  93         }
  94
  95       cs = ly_cdr (cs);
  96     }
  97
  98   if (volta_span_)
  99     {
 100       SCM l (get_property ("voltaSpannerDuration"));
 101       Moment now = now_mom ();
 102
 103       bool early_stop = unsmob_moment (l)
 104         && *unsmob_moment (l) <= now - started_mom_;
 105
 106       end = end || early_stop;
 107     }
 108
 109
 110   if (end && !volta_span_)
 111     {
 112       warning (_ ("No volta spanner to end")); // fixme: be more verbose.
 113     }
 114   else if (end)
 115     {
 116       end_volta_span_ = volta_span_;
 117       volta_span_ =0;
 118     }
 119
 120   if (volta_span_ &&
 121       (gh_string_p (start_string_) || gh_pair_p (start_string_)))
 122     {
 123       warning (_ ("Already have a volta spanner.  Stopping that one prematurely."));
 124
 125       if (end_volta_span_)
 126         {
 127           warning (_ ("Also have a stopped spanner.  Giving up."));
 128           return ;
 129         }
 130
 131       end_volta_span_ = volta_span_;
 132       volta_span_ = 0;
 133     }
 134 }
 135
 136 /*
 137   this could just as well be done in process_music (), but what the hack.
 138  */
 139 void
 140 Volta_engraver::process_acknowledged_grobs ()
 141 {
 142   if (!volta_span_ &&
 143       (gh_string_p (start_string_) || gh_pair_p (start_string_)))
 144     {
 145       started_mom_ = now_mom () ;
 146
 147       volta_span_ = new Spanner (get_property ("VoltaBracket"));
 148
 149       announce_grob (volta_span_, SCM_EOL);
 150       volta_span_->set_grob_property ("text", start_string_);
 151     }
 152 }
 153
 154 void
 155 Volta_engraver::acknowledge_grob (Grob_info i)
 156 {
 157   if (Item* item = dynamic_cast<Item*> (i.grob_))
 158     {
 159       if (Note_column::has_interface (item))
 160         {
 161           if (volta_span_)
 162             Volta_bracket_interface::add_column (volta_span_,item);
 163         }
 164       if (Bar_line::has_interface (item))
 165         {
 166           if (volta_span_)
 167             Volta_bracket_interface::add_bar (volta_span_, item);
 168           if (end_volta_span_)
 169             Volta_bracket_interface::add_bar (end_volta_span_ , item);
 170         }
 171     }
 172   else if (Staff_symbol::has_interface (i.grob_))
 173     {
 174       /*
 175         We only want to know about a single staff: then we add to the
 176         support.  */
 177       if (staff_ != SCM_EOL)
 178         staff_ = SCM_UNDEFINED;
 179
 180       if (staff_ != SCM_UNDEFINED)
 181         staff_ = i.grob_->self_scm();
 182     }
 183 }
 184
 185 void
 186 Volta_engraver::finalize ()
 187 {
 188   if (volta_span_)
 189     {
 190       typeset_grob (volta_span_);
 191     }
 192   if (end_volta_span_)
 193     {
 194       typeset_grob (end_volta_span_);
 195     }
 196 }
 197
 198
 199
 200 void
 201 Volta_engraver::stop_translation_timestep ()
 202 {
 203   if (end_volta_span_)
 204     {
 205       typeset_grob (end_volta_span_);
 206       end_volta_span_ =0;
 207     }
 208 }
 209
 210 /*
 211   TODO: should attach volta to paper-column if no bar is found.
 212  */
 213
 214 ENTER_DESCRIPTION(Volta_engraver,
 215 /* descr */       "Make volta brackets",
 216 /* creats*/       "VoltaBracket",
 217 /* accepts */     "",
 218 /* acks  */       "bar-line-interface staff-symbol-interface note-column-interface",
 219 /* reads */       "repeatCommands voltaSpannerDuration stavesFound",
 220 /* write */       "");