Implement "gray" when uicontrol radiobutton/checkbox are disabled (bug #57128) * BaseControl.cc (updatePalette): Call setColor() with additional argument of "QPalette::Active" and again with "QPalette::Inactive" so that colors are set only for specific roles. * CheckBoxControl.h (CheckBoxControl): Declare new private member function update(). * CheckBoxControl.cc (CheckBoxControl): Check for "Enable" property value of "inactive" and call setCheckable (false) if found. * CheckBoxControl.cc (update): New function to intercept and handle change to "Enable" property before forwarding to BaseControl. * RadioButtonControl.cc (RadioButtonControl): Check for "Enable" property value of "inactive" and call setCheckable (false) if found. * RadioButtonControl.cc (update): New function to intercept and handle change to "Enable" property before forwarding to BaseControl.

%!function rval = sggval (val)
%!  global gval
%!  if (nargin == 1)
%!    gval = val;
%!  else
%!    rval = gval;
%!  endif
%!endfunction

%!test
%! global gval
%! assert (isempty (gval))
%! sggval (13);
%! assert (sggval (), 13);
%! assert (gval, 13);
%! clear global gval
%! assert (sggval (), [])
%! gval = 42;
%! assert (sggval (), []);
%! clear gval
%! global gval
%! gval = 42;
%! assert (sggval (), 42);
%! clear -global gval;  # cleanup after test