lily/parenthesis-engraver.cc

   1 /*
   2   parenthesis-engraver.cc -- implement Parenthesis_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2005--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7
   8 */
   9
  10 #include "engraver.hh"
  11
  12 #include "grob.hh"
  13 #include "item.hh"
  14 #include "pointer-group-interface.hh"
  15 #include "simple-closure.hh"
  16 #include "stream-event.hh"
  17 #include "warn.hh"
  18
  19 #include "translator.icc"
  20
  21 class Parenthesis_engraver : public Engraver
  22 {
  23   TRANSLATOR_DECLARATIONS (Parenthesis_engraver);
  24
  25 protected:
  26   DECLARE_ACKNOWLEDGER (grob);
  27 };
  28
  29 Parenthesis_engraver::Parenthesis_engraver()
  30 {
  31 }
  32
  33 void
  34 Parenthesis_engraver::acknowledge_grob (Grob_info info)
  35 {
  36   if (Stream_event *ev = info.event_cause ())
  37     {
  38       if (to_boolean (ev->get_property ("parenthesize")))
  39         {
  40           if (Item *victim = dynamic_cast<Item*> (info.grob ()))
  41             {
  42               Engraver *eng = dynamic_cast<Engraver*> (info.origin_translator ());
  43               Item *paren = eng->make_item ("ParenthesesItem", victim->self_scm ());
  44
  45               Pointer_group_interface::add_grob (paren, ly_symbol2scm ("elements"), victim);
  46
  47               Real size = robust_scm2double (paren->get_property ("font-size"), 0.0)
  48                 + robust_scm2double (victim->get_property ("font-size"), 0.0);
  49               paren->set_property ("font-size", scm_from_double (size));
  50
  51               /*
  52                 TODO?
  53
  54                 enlarge victim to allow for parentheses space?
  55               */
  56             }
  57           else
  58             {
  59               programming_error ("Don't know how to parenthesize spanners.");
  60             }
  61         }
  62     }
  63 }
  64
  65 ADD_ACKNOWLEDGER (Parenthesis_engraver, grob);
  66 ADD_TRANSLATOR (Parenthesis_engraver,
  67                 /* doc */ "Parenthesize objects whose music cause has the @code{parenthesize} "
  68                 "property.",
  69
  70                 /* create */
  71                 "ParenthesesItem ",
  72                 /* accept */ "",
  73                 /* read */ "",
  74                 /* write */ "");