lily/self-aligment-interface.cc

   1 #include "self-alignment-interface.hh"
   2 #include "warn.hh"
   3
   4 /*
   5   Position centered on parent.
   6  */
   7 MAKE_SCHEME_CALLBACK (Self_alignment_interface,centered_on_parent,2);
   8 SCM
   9 Self_alignment_interface::centered_on_parent (SCM element_smob, SCM axis)
  10 {
  11   Grob *me = unsmob_grob (element_smob);
  12   Axis a = (Axis) gh_scm2int (axis);
  13   Grob *him = me->get_parent (a);
  14   Interval he = him->extent (him,a);
  15
  16   return  gh_double2scm (he.empty_b () ? 0.0 : he.center ());
  17 }
  18
  19
  20
  21 /*
  22   Position centered on parent.
  23  */
  24 MAKE_SCHEME_CALLBACK (Self_alignment_interface,centered_on_other_axis_parent,2);
  25 SCM
  26 Self_alignment_interface::centered_on_other_axis_parent (SCM element_smob,
  27                                                          SCM axis)
  28 {
  29   Grob *me = unsmob_grob (element_smob);
  30   Axis a = (Axis) gh_scm2int (axis);
  31   Grob *him = me->get_parent (other_axis (a));
  32   Interval he = him->extent (him,a);
  33
  34   return  gh_double2scm (he.empty_b () ? 0.0 : he.center ());
  35 }
  36
  37
  38
  39
  40 /**
  41   callback that centers the element on itself
  42
  43   Requires that self-alignment-{X,Y} be set.
  44  */
  45 MAKE_SCHEME_CALLBACK (Self_alignment_interface,aligned_on_self,2);
  46 SCM
  47 Self_alignment_interface::aligned_on_self (SCM element_smob, SCM axis)
  48 {
  49   Grob *me = unsmob_grob (element_smob);
  50   Axis a = (Axis) gh_scm2int (axis);
  51   static SCM  prop_syms[2];
  52
  53   if (!prop_syms[0])
  54     {
  55       prop_syms[X_AXIS] = ly_symbol2scm ("self-alignment-X");
  56       prop_syms[Y_AXIS] = ly_symbol2scm ("self-alignment-Y");
  57     }
  58
  59   SCM align (me->internal_get_grob_property (prop_syms[a]));
  60   if (gh_number_p (align))
  61     {
  62       Interval ext (me->extent (me,a));
  63
  64       if (ext.empty_b ())
  65         {
  66           programming_error ("I'm empty. Can't align on self");
  67           return gh_double2scm (0.0);
  68         }
  69       else
  70         {
  71           return gh_double2scm (- ext.linear_combination (gh_scm2double (align)));
  72         }
  73     }
  74   else if (unsmob_grob (align))
  75     {
  76       return gh_double2scm (- unsmob_grob (align)->relative_coordinate (me,  a));
  77     }
  78   return gh_double2scm (0.0);
  79 }
  80
  81
  82 ADD_INTERFACE (Self_alignment_interface, "self-alignment-interface",
  83   "Position self using some alignment",
  84   "self-alignment-X self-alignment-Y");
  85