# File gtk/sample/gtk-demo/cairo-clip.rb, line 19
    def draw(cr)
      cr.arc(0.5, 0.5, 0.3, 0, 2 * Math::PI)
      cr.clip

      cr.new_path

      cr.rectangle(0, 0, 1, 1)
      cr.fill
      cr.set_source_rgba(0, 1, 0)
      cr.move_to(0, 0)
      cr.line_to(1, 1)
      cr.move_to(1, 0)
      cr.line_to(0, 1)
      cr.stroke
    end