lily/vertical-align-engraver.cc

   1 /*
   2   vertical-align-grav.cc -- implement Vertical_align_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8 #include "translator-group.hh"
   9 #include "paper-column.hh"
  10 #include "align-interface.hh"
  11 #include "span-bar.hh"
  12 #include "axis-group-interface.hh"
  13 #include "engraver.hh"
  14 #include "spanner.hh"
  15
  16 class Vertical_align_engraver : public Engraver
  17 {
  18   Spanner * valign_;
  19   bool qualifies_b (Grob_info) const;
  20 public:
  21   TRANSLATOR_DECLARATIONS(Vertical_align_engraver);
  22 protected:
  23   virtual void acknowledge_grob (Grob_info);
  24   virtual void initialize ();
  25   virtual void finalize ();
  26 };
  27
  28 Vertical_align_engraver::Vertical_align_engraver ()
  29 {
  30   valign_ =0;
  31 }
  32
  33 void
  34 Vertical_align_engraver::initialize ()
  35 {
  36   valign_ =new Spanner (get_property ("VerticalAlignment"));
  37   valign_->set_bound (LEFT,unsmob_grob (get_property ("currentCommandColumn")));
  38   announce_grob(valign_ , SCM_EOL);
  39 }
  40
  41 void
  42 Vertical_align_engraver::finalize ()
  43 {
  44   valign_->set_bound (RIGHT,unsmob_grob (get_property ("currentCommandColumn")));
  45   typeset_grob (valign_);
  46   valign_ =0;
  47 }
  48
  49
  50 bool
  51 Vertical_align_engraver::qualifies_b (Grob_info i) const
  52 {
  53   int sz = i.origin_transes ((Translator*)this).size ()  ;
  54
  55   return sz > 1 && Axis_group_interface::has_interface (i.grob_)
  56     && !i.grob_->get_parent (Y_AXIS) && Axis_group_interface::axis_b (i.grob_, Y_AXIS);
  57 }
  58
  59 void
  60 Vertical_align_engraver::acknowledge_grob (Grob_info i)
  61 {
  62   if (qualifies_b (i))
  63     {
  64       Align_interface::add_element (valign_,i.grob_, get_property ("verticalAlignmentChildCallback"));
  65     }
  66 }
  67
  68
  69 ENTER_DESCRIPTION(Vertical_align_engraver,
  70 /* descr */       "Catch Vertical axis groups and stack them.",
  71 /* creats*/       "VerticalAlignment",
  72 /* accepts */     "",
  73 /* acks  */      "axis-group-interface",
  74 /* reads */       "",
  75 /* write */       "");