def goto_next_component
      if @current_component != nil 
        leave_current_component
        if on_last_component?
          @_entered = false
          return :UNHANDLED
        end
        @current_index = @components.index(@current_component)
        index = @current_index + 1
        index.upto(@components.length-1) do |i|
          f = @components[i]
          if f.focusable
            @current_index = i
            @current_component = f
            return set_form_row
          end
        end
      end
      @_entered = false
      return :UNHANDLED
    end
def goto_next_component
      if @current_component != nil 
        leave_current_component
        if on_last_component?
          @_entered = false
          return :UNHANDLED
        end
        @current_index = @components.index(@current_component)
        index = @current_index + 1
        index.upto(@components.length-1) do |i|
          f = @components[i]
          if f.focusable
            @current_index = i
            @current_component = f
            return set_form_row
          end
        end
      end
      @_entered = false
      return :UNHANDLED
    end
take focus to the next component or item
 Called from DOWN, RIGHT or Tab