lily/stanza-number-engraver.cc

   1 /*
   2   lyric-number-engraver.cc --  implement Stanza_number_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>, Glen Prideaux <glenprideaux@iname.com>
   7
   8 */
   9
  10 #include "engraver.hh"
  11 #include "item.hh"
  12 #include "side-position-interface.hh"
  13
  14 class Stanza_number_engraver : public Engraver
  15 {
  16   Item *text_;
  17
  18   /*
  19     This is naughty, since last_stanza_ may be GCd from under us.  But
  20     since we don't look at the contents, we are/should be (knock on
  21     wood) OK.
  22    */
  23   SCM last_stanza_;
  24 public:
  25   TRANSLATOR_DECLARATIONS (Stanza_number_engraver);
  26   virtual void process_music ();
  27   virtual void stop_translation_timestep ();
  28   virtual void acknowledge_grob (Grob_info);
  29 };
  30
  31
  32 /*
  33   TODO: should make engraver that collects all the stanzas on a higher
  34   level, and then groups them to the side. Stanza numbers should be
  35   all aligned.
  36  */
  37
  38 Stanza_number_engraver::Stanza_number_engraver ()
  39 {
  40   text_ = 0;
  41 }
  42
  43 void
  44 Stanza_number_engraver::process_music ()
  45 {
  46   SCM stanza = get_property ("stanza");
  47
  48   if (gh_string_p (stanza) && stanza != last_stanza_)
  49     {
  50       last_stanza_ = stanza;
  51
  52       text_ = make_item ("StanzaNumber");
  53       text_->set_property ("text", stanza);
  54       announce_grob (text_, SCM_EOL);
  55     }
  56 }
  57
  58
  59 void
  60 Stanza_number_engraver::acknowledge_grob (Grob_info inf)
  61 {
  62   if (text_
  63       && inf.grob_->internal_has_interface (ly_symbol2scm ("lyric-syllable-interface")))
  64     {
  65       Side_position_interface::add_support (text_, inf.grob_);
  66     }
  67 }
  68
  69 void
  70 Stanza_number_engraver::stop_translation_timestep ()
  71 {
  72   if (text_)
  73     {
  74       typeset_grob (text_);
  75       text_ = 0;
  76     }
  77 }
  78
  79
  80 ENTER_DESCRIPTION (Stanza_number_engraver,
  81 /* descr */       "",
  82 /* creats*/       "StanzaNumber",
  83 /* accepts */     "",
  84 /* acks  */      "lyric-syllable-interface",
  85 /* reads */       "stanza",
  86 /* write */       "");