lily/span-bar-engraver.cc

   1 /*
   2   span-bar-engraver.cc -- implement Span_bar_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "bar-line.hh"
  10 #include "item.hh"
  11 #include "span-bar.hh"
  12 #include "engraver.hh"
  13
  14 /**
  15
  16 Make bars that span multiple "staves". Catch bars, and span a
  17 Span_bar over them if we find more than 2 bars.  Vertical alignment
  18 of staves changes the appearance of spanbars.  It is up to the
  19 aligner (Vertical_align_engraver, in this case, to add extra
  20 dependencies to the spanbars.
  21 */
  22 class Span_bar_engraver : public Engraver
  23 {
  24   Item *spanbar_;
  25   vector<Item*> bars_;
  26
  27 public:
  28   TRANSLATOR_DECLARATIONS (Span_bar_engraver);
  29 protected:
  30   DECLARE_ACKNOWLEDGER (bar_line);
  31   void stop_translation_timestep ();
  32 };
  33
  34 Span_bar_engraver::Span_bar_engraver ()
  35 {
  36   spanbar_ = 0;
  37 }
  38
  39 void
  40 Span_bar_engraver::acknowledge_bar_line (Grob_info i)
  41 {
  42   int depth = i.origin_contexts (this).size ();
  43   if (depth && Bar_line::has_interface (i.grob ()))
  44     {
  45       Item *it = dynamic_cast<Item *> (i.grob ());
  46       bars_.push_back (it);
  47
  48       if (bars_.size () >= 2 && !spanbar_)
  49         {
  50           spanbar_ = make_item ("SpanBar", SCM_EOL);
  51
  52           spanbar_->set_parent (bars_[0], X_AXIS);
  53         }
  54     }
  55 }
  56
  57 void
  58 Span_bar_engraver::stop_translation_timestep ()
  59 {
  60   if (spanbar_)
  61     {
  62       for (vsize i = 0; i < bars_.size (); i++)
  63         Span_bar::add_bar (spanbar_, bars_[i]);
  64
  65       SCM vissym = ly_symbol2scm ("break-visibility");
  66       SCM vis = bars_[0]->internal_get_property (vissym);
  67       if (ly_is_equal (spanbar_->internal_get_property (vissym), vis))
  68         spanbar_->set_property (vissym, vis);
  69
  70       spanbar_ = 0;
  71     }
  72   bars_.resize (0);
  73 }
  74
  75 #include "translator.icc"
  76
  77 ADD_ACKNOWLEDGER (Span_bar_engraver, bar_line);
  78 ADD_TRANSLATOR (Span_bar_engraver,
  79                 /* doc */
  80                 "Make cross-staff bar lines: It catches all normal bar lines"
  81                 " and draws a single span bar across them.",
  82
  83                 /* create */
  84                 "SpanBar ",
  85
  86                 /* read */
  87                 "",
  88
  89                 /* write */
  90                 ""
  91                 );