# File gtk/sample/testgtk/notebook.rb, line 272
  def page_switch(notebook, page, page_num)
    old_page_num = notebook.page
    return if (page_num == old_page_num)
    set_page_pixmaps(notebook, page_num, @book_open, @book_open_mask)
    if (old_page_num != -1)
      set_page_pixmaps(notebook, old_page_num, @book_closed, @book_closed_mask)
    end
  end