# File gnomecanvas/sample/canvas-curve.rb, line 148
  def create_canvas(aa)
    Gtk::Widget.push_colormap(Gdk::RGB.colormap())

    canvas = Gnome::Canvas.new(aa)

    canvas.set_size_request(600, 250) #?
    canvas.set_scroll_region(0, 0, 600, 250)
    canvas.show()

    root = canvas.root

    item = Gnome::CanvasRect.new(root,
                                 {:outline_color => "black",
                                   :fill_color => "white",
                                   :x1 => 0.0,
                                   :y1 => 0.0,
                                   :x2 => 600.0,
                                   :y2 => 250.0})

    Gnome::CanvasText.new(root,
                          {:text => aa ? "AntiAlias" : "Non-AntiAlias",
                            :x => 270.0,
                            :y => 5.0,
                            :font => "Sans 12",
                            :anchor => Gtk::ANCHOR_N,
                            :fill_color => "black"})

    Gtk::Widget.pop_colormap()

    item.signal_connect("event") do |item, event|
      canvas_event(item, event)
    end

    frame = Gtk::Frame.new()
    frame.shadow_type = Gtk::SHADOW_IN

    frame.add(canvas)
    frame
  end