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--2000 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8 #include "translator-group.hh"
   9 #include "axis-group-engraver.hh"
  10 #include "paper-column.hh"
  11 #include "align-interface.hh"
  12 #include "span-bar.hh"
  13 #include "axis-group-interface.hh"
  14 #include "engraver.hh"
  15 #include "spanner.hh"
  16
  17 class Vertical_align_engraver : public Engraver {
  18   Spanner * valign_p_;
  19   bool qualifies_b (Score_element_info) const;
  20 public:
  21   VIRTUAL_COPY_CONS(Translator);
  22
  23   Vertical_align_engraver();
  24 protected:
  25
  26   virtual void acknowledge_element (Score_element_info);
  27   virtual void do_creation_processing();
  28   virtual void do_removal_processing();
  29 };
  30
  31
  32 Vertical_align_engraver::Vertical_align_engraver()
  33 {
  34   valign_p_ =0;
  35 }
  36
  37 void
  38 Vertical_align_engraver::do_creation_processing()
  39 {
  40   valign_p_ =new Spanner (SCM_EOL); // todo -> basic props
  41   Align_interface (valign_p_).set_interface ();
  42   Align_interface (valign_p_).set_axis (Y_AXIS);
  43   valign_p_->set_elt_property ("stacking-dir",
  44                                gh_int2scm (DOWN));
  45
  46   valign_p_->set_bound(LEFT,unsmob_element (get_property ("currentCommandColumn")));
  47   announce_element (Score_element_info (valign_p_ , 0));
  48 }
  49
  50 void
  51 Vertical_align_engraver::do_removal_processing()
  52 {
  53   SCM min = get_property ("maxVerticalAlign");
  54   SCM max = get_property ("minVerticalAlign");
  55
  56   if (gh_number_p (min) || gh_number_p (max))
  57   {
  58     min = gh_number_p (min) ? min : gh_double2scm (0.0);
  59     max = gh_number_p (max) ? max : gh_double2scm (infinity_f);
  60
  61     valign_p_->set_elt_property ("threshold",
  62                                  gh_cons (min,max));
  63   }
  64   valign_p_->set_bound(RIGHT,unsmob_element (get_property ("currentCommandColumn")));
  65   typeset_element (valign_p_);
  66   valign_p_ =0;
  67 }
  68
  69
  70 bool
  71 Vertical_align_engraver::qualifies_b (Score_element_info i) const
  72 {
  73   int sz = i.origin_trans_l_arr ((Translator*)this).size()  ;
  74
  75
  76   Axis_group_interface agi(i.elem_l_);
  77
  78   return sz > 1 && agi.has_interface_b ()
  79     && !i.elem_l_->parent_l (Y_AXIS) && agi.axis_b (Y_AXIS);
  80 }
  81
  82 void
  83 Vertical_align_engraver::acknowledge_element (Score_element_info i)
  84 {
  85   if (qualifies_b (i))
  86     {
  87       Align_interface(valign_p_).add_element (i.elem_l_);
  88     }
  89 }
  90
  91
  92
  93 ADD_THIS_TRANSLATOR(Vertical_align_engraver);