lily/span-bar-engraver.cc

   1 /*
   2   span-bar-grav.cc -- implement Span_bar_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9
  10 #include "lily-guile.hh"
  11 #include "bar-line.hh"
  12 #include "item.hh"
  13 #include "span-bar.hh"
  14 #include "engraver.hh"
  15
  16
  17 /**
  18
  19   Make bars that span multiple "staves". Catch bars, and span a
  20   Span_bar over them if we find more than 2 bars.  Vertical alignment
  21   of staves changes the appearance of spanbars.  It is up to the
  22   aligner (Vertical_align_engraver, in this case, to add extra
  23   dependencies to the spanbars.
  24
  25   */
  26 class Span_bar_engraver : public Engraver
  27 {
  28   Item *spanbar_;
  29   Link_array<Item> bars_;
  30
  31 public:
  32   TRANSLATOR_DECLARATIONS (Span_bar_engraver);
  33 protected:
  34   virtual void acknowledge_grob (Grob_info);
  35   virtual void stop_translation_timestep ();
  36 };
  37
  38 Span_bar_engraver::Span_bar_engraver ()
  39 {
  40   spanbar_ =0;
  41 }
  42
  43 void
  44 Span_bar_engraver::acknowledge_grob (Grob_info i)
  45 {
  46   int depth = i.origin_contexts (this).size ();
  47   if (depth && Bar_line::has_interface (i.grob_))
  48     {
  49       Item * it = dynamic_cast<Item*> (i.grob_);
  50       bars_.push (it);
  51
  52       if (bars_.size () >= 2 && !spanbar_)
  53         {
  54           spanbar_ = make_item ("SpanBar");
  55
  56           spanbar_->set_parent (bars_[0], X_AXIS);
  57           announce_grob (spanbar_, SCM_EOL);
  58         }
  59     }
  60 }
  61
  62 void
  63 Span_bar_engraver::stop_translation_timestep ()
  64 {
  65   if (spanbar_)
  66     {
  67       for (int i=0; i < bars_.size () ; i++)
  68         Span_bar::add_bar (spanbar_,bars_[i]);
  69
  70       SCM vissym =ly_symbol2scm ("break-visibility");
  71       SCM vis = bars_[0]->internal_get_property (vissym);
  72       if (gh_equal_p (spanbar_->internal_get_property (vissym), vis))
  73         spanbar_->internal_set_property (vissym, vis);
  74
  75       typeset_grob (spanbar_);
  76       spanbar_ =0;
  77     }
  78   bars_.set_size (0);
  79 }
  80
  81
  82 ENTER_DESCRIPTION (Span_bar_engraver,
  83 /* descr */       "This engraver makes cross-staff barlines: It catches all normal "
  84 "bar lines, and draws a single span-bar across them.",
  85 /* creats*/       "SpanBar",
  86 /* accepts */     "",
  87 /* acks  */      "bar-line-interface",
  88 /* reads */       "",
  89 /* write */       "");