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--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "engraver.hh"
  10 #include "translator-group.hh"
  11 #include "context.hh"
  12 #include "repeated-music.hh"
  13
  14 #include "translator.icc"
  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 class Repeat_acknowledge_engraver : public Engraver
  27 {
  28 public:
  29
  30   TRANSLATOR_DECLARATIONS (Repeat_acknowledge_engraver);
  31 protected:
  32   void start_translation_timestep ();
  33   void process_music ();
  34   virtual void initialize ();
  35 };
  36
  37 void
  38 Repeat_acknowledge_engraver::initialize ()
  39 {
  40   context ()->set_property ("repeatCommands", SCM_EOL);
  41 }
  42
  43 Repeat_acknowledge_engraver::Repeat_acknowledge_engraver ()
  44 {
  45 }
  46
  47 void
  48 Repeat_acknowledge_engraver::start_translation_timestep ()
  49 {
  50   SCM rc;
  51   Context *tr = context ()->where_defined (ly_symbol2scm ("repeatCommands"), &rc);
  52   if (!tr)
  53     tr = context ();
  54
  55   tr->set_property ("repeatCommands", SCM_EOL);
  56 }
  57
  58 void
  59 Repeat_acknowledge_engraver::process_music ()
  60 {
  61   /*
  62     At the start of a piece, we don't print any repeat bars.
  63   */
  64   if (!now_mom ().main_part_)
  65     return;
  66
  67   SCM cs = get_property ("repeatCommands");
  68
  69   string s = "";
  70   bool start = false;
  71   bool end = false;
  72   bool volta_found = false;
  73   while (scm_is_pair (cs))
  74     {
  75       SCM command = scm_car (cs);
  76       if (command == ly_symbol2scm ("start-repeat"))
  77         start = true;
  78       else if (command == ly_symbol2scm ("end-repeat"))
  79         end = true;
  80       else if (scm_is_pair (command) && scm_car (command) == ly_symbol2scm ("volta"))
  81         volta_found = true;
  82       cs = scm_cdr (cs);
  83     }
  84
  85   if (start && end)
  86     s = ":|:";
  87   else if (start)
  88     s = "|:";
  89   else if (end)
  90     s = ":|";
  91
  92   /*
  93     TODO: line breaks might be allowed if we set whichBar to "".
  94   */
  95
  96   /*
  97     We only set the barline if we wouldn't overwrite a previously set
  98     barline.
  99   */
 100   SCM wb = get_property ("whichBar");
 101   SCM db = get_property ("defaultBarType");
 102   if (!scm_is_string (wb) || ly_is_equal (db, wb))
 103     {
 104       if (s != "" || (volta_found && !scm_is_string (wb)))
 105         context ()->set_property ("whichBar", ly_string2scm (s));
 106     }
 107 }
 108
 109 ADD_TRANSLATOR (Repeat_acknowledge_engraver,
 110                 /* doc */
 111                 "Acknowledge repeated music, and convert the contents of"
 112                 " @code{repeatCommands} into an appropriate setting for"
 113                 " @code{whichBar}.",
 114
 115                 /* create */
 116                 "",
 117
 118                 /* read */
 119                 "repeatCommands "
 120                 "whichBar ",
 121
 122                 /* write */
 123                 ""
 124                 );