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.

To cite GNU Octave in publications use:

  John W. Eaton, David Bateman, Søren Hauberg, Rik Wehbring (2019).
  GNU Octave version 5.2.0 manual: a high-level interactive language for
  numerical computations.
  URL https://www.gnu.org/software/octave/doc/v5.2.0/

A BibTeX entry for LaTeX users is:

  @manual{,
    title     = {{GNU Octave} version 5.2.0 manual: a high-level interactive language for numerical computations},
    author    = {John W. Eaton and David Bateman and S{\o}ren Hauberg and Rik Wehbring},
    year      = {2020},
    url       = {https://www.gnu.org/software/octave/doc/v5.2.0/},
  }

We have invested a lot of time and effort in creating GNU Octave, please
cite it when using it.  See also 'citation pkgname' for citing Octave
packages.