lily/bar-engraver.cc

   1 /*
   2   bar-engraver.cc -- implement Bar_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7   Jan Nieuwenhuizen <janneke@gnu.org>
   8 */
   9
  10 #include "bar-line.hh"
  11 #include "context.hh"
  12 #include "score-engraver.hh"
  13 #include "warn.hh"
  14 #include "item.hh"
  15
  16 #include "translator.icc"
  17
  18 /*
  19   generate bars. Either user ("|:"), or default (new measure)
  20 */
  21 class Bar_engraver : public Engraver
  22 {
  23 public:
  24   TRANSLATOR_DECLARATIONS (Bar_engraver);
  25   void request_bar (string type_string);
  26
  27 protected:
  28   virtual void finalize ();
  29   void stop_translation_timestep ();
  30   void process_acknowledged ();
  31
  32 private:
  33   void typeset_bar ();
  34   void create_bar ();
  35
  36   Item *bar_;
  37 };
  38
  39 Bar_engraver::Bar_engraver ()
  40 {
  41   bar_ = 0;
  42 }
  43
  44 void
  45 Bar_engraver::create_bar ()
  46 {
  47   if (!bar_)
  48     {
  49       bar_ = make_item ("BarLine", SCM_EOL);
  50       SCM gl = get_property ("whichBar");
  51       if (scm_equal_p (gl, bar_->get_property ("glyph")) != SCM_BOOL_T)
  52         bar_->set_property ("glyph", gl);
  53     }
  54 }
  55
  56 void
  57 Bar_engraver::finalize ()
  58 {
  59   typeset_bar ();
  60 }
  61
  62 /*
  63   Bar_engraver should come *after* any engravers that
  64   modify whichBar
  65
  66   This is a little hairy : whichBar may be set by
  67   Repeat_acknowledge_engraver::process_music, which is at score
  68   context. This means that grobs could should be created after
  69   process_music. We do stuff process_acknowledged (), just to be
  70   on the safe side.
  71 */
  72
  73 void
  74 Bar_engraver::process_acknowledged ()
  75 {
  76   if (!bar_ && scm_is_string (get_property ("whichBar")))
  77     create_bar ();
  78 }
  79
  80 void
  81 Bar_engraver::typeset_bar ()
  82 {
  83   bar_ = 0;
  84 }
  85
  86 /*
  87   lines may only be broken if there is a barline in all staves
  88 */
  89 void
  90 Bar_engraver::stop_translation_timestep ()
  91 {
  92   if (!bar_)
  93     context ()->get_score_context ()->set_property ("forbidBreak", SCM_BOOL_T);
  94   else
  95     typeset_bar ();
  96 }
  97
  98 ADD_TRANSLATOR (Bar_engraver,
  99                 /* doc */ "Create barlines. This engraver is controlled through the "
 100                 "@code{whichBar} property. If it has no bar line to create, it will forbid a linebreak at this point",
 101                 /* create */ "BarLine",
 102                 /* accept */ "",
 103                 /* read */ "whichBar",
 104                 /* write */ "forbidBreak");