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--2009 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 #include "spanner.hh"
  16
  17 #include "translator.icc"
  18
  19 /*
  20   generate bars. Either user ("|:"), or default (new measure)
  21 */
  22 class Bar_engraver : public Engraver
  23 {
  24 public:
  25   TRANSLATOR_DECLARATIONS (Bar_engraver);
  26   void request_bar (string type_string);
  27
  28 protected:
  29   void stop_translation_timestep ();
  30   void process_acknowledged ();
  31
  32   DECLARE_END_ACKNOWLEDGER (spanner);
  33
  34 private:
  35   void create_bar ();
  36
  37   Item *bar_;
  38   vector<Spanner*> spanners_;
  39 };
  40
  41 Bar_engraver::Bar_engraver ()
  42 {
  43   bar_ = 0;
  44 }
  45
  46 void
  47 Bar_engraver::create_bar ()
  48 {
  49   if (!bar_)
  50     {
  51       bar_ = make_item ("BarLine", SCM_EOL);
  52       SCM gl = get_property ("whichBar");
  53       if (scm_equal_p (gl, bar_->get_property ("glyph")) != SCM_BOOL_T)
  54         bar_->set_property ("glyph", gl);
  55     }
  56 }
  57
  58 /*
  59   Bar_engraver should come *after* any engravers that
  60   modify whichBar
  61
  62   This is a little hairy : whichBar may be set by
  63   Repeat_acknowledge_engraver::process_music, which is at score
  64   context. This means that grobs could should be created after
  65   process_music. We do stuff process_acknowledged (), just to be
  66   on the safe side.
  67 */
  68
  69 void
  70 Bar_engraver::process_acknowledged ()
  71 {
  72   if (!bar_ && scm_is_string (get_property ("whichBar")))
  73     create_bar ();
  74
  75   if (bar_)
  76     for (vsize i = 0; i < spanners_.size (); i++)
  77       spanners_[i]->set_bound (RIGHT, bar_);
  78 }
  79
  80 /*
  81   lines may only be broken if there is a barline in all staves
  82 */
  83 void
  84 Bar_engraver::stop_translation_timestep ()
  85 {
  86   if (!bar_)
  87     context ()->get_score_context ()->set_property ("forbidBreak", SCM_BOOL_T);
  88
  89   bar_ = 0;
  90   spanners_.clear ();
  91 }
  92
  93 void
  94 Bar_engraver::acknowledge_end_spanner (Grob_info gi)
  95 {
  96   Grob *g = gi.grob ();
  97
  98   if (to_boolean (g->get_property ("to-barline")))
  99     spanners_.push_back (dynamic_cast<Spanner*> (g));
 100 }
 101
 102 ADD_END_ACKNOWLEDGER (Bar_engraver, spanner);
 103
 104 ADD_TRANSLATOR (Bar_engraver,
 105                 /* doc */
 106                 "Create barlines.  This engraver is controlled through the"
 107                 " @code{whichBar} property.  If it has no bar line to create,"
 108                 " it will forbid a linebreak at this point.",
 109
 110                 /* create */
 111                 "BarLine ",
 112
 113                 /* read */
 114                 "whichBar ",
 115
 116                 /* write */
 117                 "forbidBreak "
 118                 );