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--2002 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7   Jan Nieuwenhuizen <janneke@gnu.org>
   8 */
   9
  10 #include "bar-line.hh"
  11 #include "score-engraver.hh"
  12 #include "musical-request.hh"
  13 #include "engraver-group-engraver.hh"
  14 #include "warn.hh"
  15 #include "item.hh"
  16 #include "engraver.hh"
  17
  18 /*
  19   generate bars. Either user ("|:"), or default (new measure)
  20
  21   */
  22 class Bar_engraver : public Engraver
  23 {
  24 public:
  25   TRANSLATOR_DECLARATIONS(  Bar_engraver );
  26   void request_bar (String type_str);
  27
  28 protected:
  29   virtual void finalize ();
  30   virtual void stop_translation_timestep ();
  31   virtual void create_grobs ();
  32
  33 private:
  34   void typeset_bar ();
  35   void create_bar ();
  36
  37   Item * bar_p_;
  38 };
  39
  40 Bar_engraver::Bar_engraver ()
  41 {
  42   bar_p_ =0;
  43 }
  44
  45 void
  46 Bar_engraver::create_bar ()
  47 {
  48   if (!bar_p_)
  49     {
  50       bar_p_ = new Item (get_property ("BarLine"));
  51
  52       SCM gl = get_property ("whichBar");
  53       if (scm_equal_p (gl, bar_p_->get_grob_property ("glyph")) != SCM_BOOL_T)
  54           bar_p_->set_grob_property ("glyph", gl);
  55
  56       announce_grob(bar_p_, SCM_EOL);
  57     }
  58 }
  59
  60 void
  61 Bar_engraver::finalize ()
  62 {
  63   typeset_bar ();
  64 }
  65
  66 /*
  67   Bar_engraver should come *after* any engravers that
  68   modify whichBar
  69 */
  70 void
  71 Bar_engraver::create_grobs ()
  72 {
  73   if (!bar_p_ && gh_string_p (get_property ("whichBar")))
  74     {
  75       create_bar ();
  76     }
  77 }
  78
  79 void
  80 Bar_engraver::typeset_bar ()
  81 {
  82   if (bar_p_)
  83     {
  84       typeset_grob (bar_p_);
  85       bar_p_ =0;
  86     }
  87 }
  88
  89 /*
  90   lines may only be broken if there is a barline in all staves
  91 */
  92 void
  93 Bar_engraver::stop_translation_timestep ()
  94 {
  95   if (!bar_p_)
  96     {
  97       top_engraver ()->forbid_breaks ();        // guh. Use properties!
  98     }
  99   else
 100     typeset_bar ();
 101 }
 102
 103
 104 ENTER_DESCRIPTION(Bar_engraver,
 105 /* descr */       "Create barlines. This engraver is controlled through the
 106 @code{whichBar} property. If it has no bar line to create, it will forbid a linebreak at this point",
 107 /* creats*/       "BarLine",
 108 /* acks  */       "",
 109 /* reads */       "whichBar",
 110 /* write */       "");