# File gtk/sample/gtk-demo/colorsel.rb, line 15
    def initialize
      super('Color Selection')

      @color = Gdk::Color.new(0, 0, 65535)

      set_border_width(8)
      
      vbox = Gtk::VBox.new(false, 0)
      vbox.set_border_width(8)
      add(vbox)

      ## Create the color swatch area
      @frame = Gtk::Frame.new
      @frame.set_shadow_type(Gtk::SHADOW_IN)
      vbox.pack_start(@frame, true, true, 0)

      @da = Gtk::DrawingArea.new
      
      @da.signal_connect('expose_event') do |widget, event|
        if widget.window
          style = widget.style

          widget.window.draw_rectangle(style.bg_gc(Gtk::STATE_NORMAL),
                                       true,
                                       event.area.x, event.area.y,
                                       event.area.width, event.area.height)
        end
      end

      # set a minimum size
      @da.set_size_request(200, 200)
      # set the color
      @da.modify_bg(Gtk::STATE_NORMAL, @color)

      @frame.add(@da)

      alignment = Gtk::Alignment.new(1.0, 0.5, 0.0, 0.0)

      button = Gtk::Button.new('_Change the above color', true)
      alignment.add(button)

      vbox.pack_start(alignment, false, false, 0)

      button.signal_connect('clicked') do
        change_color_callback
      end
    end