buttons.add(button);
addGap(buttons, "10px");
final ToggleToolButton tb1 = new ToggleToolButton(WidgetImages.Instance.get().icon_CubeGreen().createImage());
tb1.addChangeHandler(new ChangeHandler() {
public void onChange(ChangeEvent event) {
showMessage("Green Cube " + (tb1.isDown() ? "DOWN" : "UP"));
}
});
buttons.add(tb1);