def focusable(*val)
      return @focusable if val.empty?
      oldv = @focusable
      @focusable = val[0]

      return self if oldv.nil? || @_object_created.nil?
      # once the form has been painted then any changes will trigger update of focusables.
      @form.update_focusables if @form
      # actually i should only set the forms focusable_modified flag rather than call this. FIXME
      self
    end
def focusable(*val)
      return @focusable if val.empty?
      oldv = @focusable
      @focusable = val[0]

      return self if oldv.nil? || @_object_created.nil?
      # once the form has been painted then any changes will trigger update of focusables.
      @form.update_focusables if @form
      # actually i should only set the forms focusable_modified flag rather than call this. FIXME
      self
    end
set or unset focusable (boolean). Whether a widget can get keyboard focus.