# File gtk/sample/gtk-demo/common.rb, line 53
    def initialize(title=nil)
      super
      
      unless Gdk.cairo_available?
        add_cairo_require_label
        return
      end

      drawing_area = Gtk::DrawingArea.new
      add(drawing_area)

      drawing_area.signal_connect("expose_event") do |widget, event|
        cr = widget.window.create_cairo_context
        cr.scale(*widget.window.size)
        cr.set_line_width(0.04)

        cr.save do
          cr.set_source_color(Gdk::Color.new(65535, 65535, 65535))
          cr.gdk_rectangle(Gdk::Rectangle.new(0, 0, 1, 1))
          cr.fill
        end
        
        draw(cr)
      end
    end