# File gtk/sample/gtk-demo/changedisplay.rb, line 103
    def initialize_displays
      manager = Gdk::DisplayManager.get

      manager.displays.each do |display|
        add_display(display)
      end

      handler_id = manager.signal_connect('display_opened') do |display|
        add_display(display)
      end
      signal_connect('destroy') do
        manager.signal_handler_disconnect(handler_id)
      end
    end