# File gtk/sample/gtk-demo/main.rb, line 202
    def row_activated_cb(model, path)
      iter = model.get_iter(path)
      iter.set_value(ITALIC_COLUMN, true)

      lib = iter.get_value(FILENAME_COLUMN)
      if lib
        require(lib)
 
        klass = Demo.const_get(iter.get_value(CLASS_COLUMN))
        window = klass.new
        window.signal_connect('destroy') do
          iter.set_value(ITALIC_COLUMN, false)
        end
        window.show_all
        @window = window
      end
    end