controls_table.attach (hide_button, 0, 1, 1, 2, Gtk::FILL|Gtk::EXPAND, Gtk::FILL|Gtk::EXPAND);
controls_table.attach (visual_button, 1, 2, 1, 2, Gtk::FILL|Gtk::EXPAND, Gtk::FILL|Gtk::EXPAND);
controls_table.attach (size_button, 2, 3, 1, 2, Gtk::FILL|Gtk::EXPAND, Gtk::FILL|Gtk::EXPAND);
controls_table.attach (hide_button, 0, 1, 1, 2, Gtk::FILL|Gtk::EXPAND, Gtk::FILL|Gtk::EXPAND);
controls_table.attach (visual_button, 1, 2, 1, 2, Gtk::FILL|Gtk::EXPAND, Gtk::FILL|Gtk::EXPAND);
controls_table.attach (size_button, 2, 3, 1, 2, Gtk::FILL|Gtk::EXPAND, Gtk::FILL|Gtk::EXPAND);