Button beh = new Button(Behavior.BOTH.name()).onClick(new Slot<Button>() {
@Override public void onEmit (Button source) {
Behavior[] behs = Behavior.values();
Behavior beh = Behavior.valueOf(source.text.get());
beh = behs[(beh.ordinal() + 1) % behs.length];
scroll.setBehavior(beh);
source.text.update(beh.name());
xpos.setVisible(beh.hasHorizontal());
ypos.setVisible(beh.hasVertical());
updateSize.onEmit();