lily/extender-engraver.cc

   1 /*
   2   extender-engraver.cc -- implement Extender_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1999--2004 Glen Prideaux <glenprideaux@iname.com>,
   7                   Han-Wen Nienhuys <hanwen@cs.uu.nl>,
   8                   Jan Nieuwenhuizen <janneke@gnu.org>
   9 */
  10
  11 #include "warn.hh"
  12 #include "lyric-extender.hh"
  13 #include "item.hh"
  14 #include "engraver.hh"
  15
  16 class Extender_engraver : public Engraver
  17 {
  18   Music* ev_;
  19   Spanner* extender_;
  20   Spanner * finished_extender_;
  21 public:
  22   TRANSLATOR_DECLARATIONS(Extender_engraver);
  23
  24 protected:
  25   virtual void acknowledge_grob (Grob_info);
  26   virtual void finalize ();
  27   virtual bool try_music (Music*);
  28   virtual void stop_translation_timestep ();
  29   virtual void process_music ();
  30 private:
  31
  32 };
  33
  34
  35
  36
  37 Extender_engraver::Extender_engraver ()
  38 {
  39   extender_ = 0;
  40   finished_extender_ = 0;
  41   ev_ = 0;
  42 }
  43
  44 void
  45 Extender_engraver::acknowledge_grob (Grob_info i)
  46 {
  47   Item * item =  dynamic_cast<Item*> (i.grob_);
  48   // -> text_item
  49   if (item && item->internal_has_interface (ly_symbol2scm ("lyric-syllable-interface")))
  50     {
  51       if (extender_)
  52         extender_->set_bound (LEFT, item);
  53
  54       if (finished_extender_)
  55         finished_extender_->set_bound (RIGHT, item);
  56     }
  57 }
  58
  59
  60 bool
  61 Extender_engraver::try_music (Music* r)
  62 {
  63   if (ev_)
  64     return false;
  65
  66   ev_ = r;
  67   return true;
  68 }
  69
  70 void
  71 completize_extender (Spanner* sp)
  72 {
  73   if (!sp->get_bound (RIGHT))
  74     {
  75       SCM heads = sp->get_grob_property ("heads");
  76       if (gh_pair_p (heads))
  77         {
  78           Item* it = dynamic_cast<Item*> (unsmob_grob (gh_car (heads)));
  79           if (it)
  80             sp->set_bound (RIGHT, it);
  81         }
  82     }
  83 }
  84
  85
  86
  87 void
  88 Extender_engraver::finalize ()
  89 {
  90   if (extender_)
  91     {
  92       completize_extender (extender_);
  93
  94       if (!extender_->get_bound (RIGHT))
  95         extender_->warning (_ ("unterminated extender"));
  96       typeset_grob (extender_);
  97       extender_ = 0;
  98     }
  99
 100   if (finished_extender_)
 101     {
 102       completize_extender (finished_extender_);
 103
 104       if (!finished_extender_->get_bound (RIGHT))
 105           finished_extender_->warning (_("unterminated extender"));
 106       typeset_grob (finished_extender_);
 107       finished_extender_ =0;
 108     }
 109 }
 110
 111 void
 112 Extender_engraver::process_music ()
 113 {
 114   if (ev_)
 115     {
 116       extender_ = make_spanner ("LyricExtender");
 117       announce_grob (extender_, ev_->self_scm());
 118     }
 119 }
 120
 121
 122 void
 123 Extender_engraver::stop_translation_timestep ()
 124 {
 125   if (finished_extender_ && finished_extender_->get_bound (RIGHT))
 126     {
 127       typeset_grob (finished_extender_);
 128       finished_extender_ = 0;
 129     }
 130
 131   if (finished_extender_ && extender_)
 132     {
 133       programming_error ("Haven't finished extender yet.");
 134       typeset_grob (finished_extender_);
 135       finished_extender_ =0;
 136     }
 137
 138   if (extender_)
 139     finished_extender_ = extender_;
 140   extender_ = 0;
 141
 142   ev_ = 0;
 143 }
 144
 145
 146
 147 ENTER_DESCRIPTION(Extender_engraver,
 148 /* descr */       "Create lyric extenders",
 149 /* creats*/       "LyricExtender",
 150 /* accepts */     "extender-event",
 151 /* acks  */       "lyric-syllable-interface",
 152 /* reads */       "",
 153 /* write */       "");