p.add(new Button("change value with event", new ClickHandler() {
public void onClick(ClickEvent event) {
b.setValue(false, true);
}
}));
b.addKeyboardListener(handler);
HandlesAllKeyEvents.addHandlers(b, handler);
b.addFocusHandler(handler);
b.addBlurHandler(handler);
b.addFocusListener(handler);
b.addValueChangeHandler(handler);