lily/repeat-acknowledge-engraver.cc

   1 /*
   2   repeat-acknowledge-engraver.cc --  implement Repeat_acknowledge_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 #include "engraver.hh"
  10 #include "translator-group.hh"
  11 #include "repeated-music.hh"
  12
  13
  14 /*
  15   Objective:
  16
  17   -- set and reset repeatCommands, so Unfolded_repeat_iterator knows
  18     where to set variables.
  19
  20   -- collect information passed by Unfolded_repeat_iterator for
  21    Bar_engraver: writes whichBar property. (TODO: check for
  22    interactions with timing engraver.)
  23
  24  */
  25 class Repeat_acknowledge_engraver : public Engraver
  26 {
  27 public:
  28   TRANSLATOR_DECLARATIONS(Repeat_acknowledge_engraver);
  29
  30   virtual void start_translation_timestep ();
  31   virtual void process_music ();
  32   virtual void initialize ();
  33
  34   bool first_b_;
  35 };
  36
  37 void
  38 Repeat_acknowledge_engraver::initialize ()
  39 {
  40   first_b_ = true;
  41   daddy_trans_->set_property ("repeatCommands", SCM_EOL);
  42 }
  43
  44
  45 Repeat_acknowledge_engraver::Repeat_acknowledge_engraver ()
  46 {
  47 }
  48
  49 void
  50 Repeat_acknowledge_engraver::start_translation_timestep ()
  51 {
  52   first_b_ = true;
  53   Translator_group * tr = daddy_trans_->where_defined (ly_symbol2scm ("repeatCommands"));
  54   if (!tr)
  55     tr = daddy_trans_;
  56
  57   tr->set_property ("repeatCommands", SCM_EOL);
  58 }
  59
  60 void
  61 Repeat_acknowledge_engraver::process_music ()
  62 {
  63   /*
  64     At the start of a piece, we don't print any repeat bars.
  65    */
  66   if (now_mom () == Moment (0))
  67     return ;
  68
  69   SCM cs = get_property ("repeatCommands");
  70
  71   String s = "";
  72   bool start = false;
  73   bool end = false;
  74   bool volta_found = false;
  75   while (gh_pair_p (cs))
  76     {
  77       SCM command = ly_car (cs);
  78       if (command == ly_symbol2scm ("start-repeat"))
  79         start = true;
  80       else if (command == ly_symbol2scm ("end-repeat"))
  81         end = true;
  82       else if (gh_pair_p (command) && ly_car (command) == ly_symbol2scm ("volta"))
  83         volta_found = true;
  84       cs = ly_cdr (cs);
  85     }
  86
  87   if (start && end)
  88     s = ":|:";
  89   else if (start)
  90     s = "|:";
  91   else if (end)
  92     s = ":|";
  93
  94   /*
  95     TODO: line breaks might be allowed if we set whichBar to "".
  96    */
  97
  98   /*
  99     We only set the barline if we wouldn't overwrite a previously set
 100     barline.
 101    */
 102   SCM wb = get_property ("whichBar");
 103   SCM db  = get_property ("defaultBarType");
 104   if (!gh_string_p (wb) || gh_equal_p (db, wb))
 105     {
 106       if (s != "" || (volta_found && !gh_string_p (wb)))
 107         {
 108           daddy_trans_->set_property ("whichBar", scm_makfrom0str (s.to_str0 ()));
 109         }
 110     }
 111 }
 112
 113 ENTER_DESCRIPTION(Repeat_acknowledge_engraver,
 114 /* descr */       "Acknowledge repeated music, and convert the contents of
 115 repeatCommands ainto an appropriate setting for whichBar",
 116 /* creats*/       "",
 117 /* acks  */       "",
 118 /* reads */       "repeatCommands whichBar",
 119 /* write */       "");