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--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "engraver.hh"
  11 #include "translator-group.hh"
  12 #include "context.hh"
  13 #include "repeated-music.hh"
  14
  15
  16 /*
  17   Objective:
  18
  19   -- set and reset repeatCommands, so Unfolded_repeat_iterator knows
  20     where to set variables.
  21
  22   -- collect information passed by Unfolded_repeat_iterator for
  23    Bar_engraver: writes whichBar property. (TODO: check for
  24    interactions with timing engraver.)
  25
  26  */
  27 class Repeat_acknowledge_engraver : public Engraver
  28 {
  29 public:
  30   TRANSLATOR_DECLARATIONS (Repeat_acknowledge_engraver);
  31
  32   virtual void start_translation_timestep ();
  33   virtual void process_music ();
  34   virtual void initialize ();
  35
  36 };
  37
  38 void
  39 Repeat_acknowledge_engraver::initialize ()
  40 {
  41   daddy_context_->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   Context * tr = daddy_context_->where_defined (ly_symbol2scm ("repeatCommands"));
  53   if (!tr)
  54     tr = daddy_context_;
  55
  56   tr->set_property ("repeatCommands", SCM_EOL);
  57 }
  58
  59 void
  60 Repeat_acknowledge_engraver::process_music ()
  61 {
  62   /*
  63     At the start of a piece, we don't print any repeat bars.
  64    */
  65   if (now_mom () == Moment (0))
  66     return ;
  67
  68   SCM cs = get_property ("repeatCommands");
  69
  70   String s = "";
  71   bool start = false;
  72   bool end = false;
  73   bool volta_found = false;
  74   while (ly_pair_p (cs))
  75     {
  76       SCM command = ly_car (cs);
  77       if (command == ly_symbol2scm ("start-repeat"))
  78         start = true;
  79       else if (command == ly_symbol2scm ("end-repeat"))
  80         end = true;
  81       else if (ly_pair_p (command) && ly_car (command) == ly_symbol2scm ("volta"))
  82         volta_found = true;
  83       cs = ly_cdr (cs);
  84     }
  85
  86   if (start && end)
  87     s = ":|:";
  88   else if (start)
  89     s = "|:";
  90   else if (end)
  91     s = ":|";
  92
  93   /*
  94     TODO: line breaks might be allowed if we set whichBar to "".
  95    */
  96
  97   /*
  98     We only set the barline if we wouldn't overwrite a previously set
  99     barline.
 100    */
 101   SCM wb = get_property ("whichBar");
 102   SCM db  = get_property ("defaultBarType");
 103   if (!ly_string_p (wb) || ly_equal_p (db, wb))
 104     {
 105       if (s != "" || (volta_found && !ly_string_p (wb)))
 106         {
 107           daddy_context_->set_property ("whichBar", scm_makfrom0str (s.to_str0 ()));
 108         }
 109     }
 110 }
 111
 112 ENTER_DESCRIPTION (Repeat_acknowledge_engraver,
 113 /* descr */       "Acknowledge repeated music, and convert the contents of "
 114 "repeatCommands ainto an appropriate setting for whichBar.",
 115 /* creats*/       "",
 116 /* accepts */     "",
 117 /* acks  */      "",
 118 /* reads */       "repeatCommands whichBar",
 119 /* write */       "");