An example of old ruby-gtk code

before.rb

      @hbox = Gtk::HBox.new(true, 0)
      self.add(@hbox)

      @vbox = Gtk::VBox.new(false, 0)
      @hbox.pack_start(@vbox, true, true, WIDGET_SPACING)

      @image = Gtk::DrawingArea.new
      @vbox.pack_start(@image, true, true, WIDGET_SPACING)

      @code_text = Gtk::TextView.new
      @code_text.set_size_request(200, 200)
      @vbox.pack_start(@code_text, false, false, WIDGET_SPACING)

      @button = Gtk::Button.new("Run")
      @button.signal_connect("clicked") { self.run_code }
      @vbox.pack_start(@button, false, false, WIDGET_SPACING)