final VerticalSplitPanel vsplit = new VerticalSplitPanel();
vsplit.setSizeFull();
vsplit.setImmediate(true);
vsplit.setSplitPosition(10, Sizeable.UNITS_PERCENTAGE, vsplitReversed);
vsplit.addListener(new SplitterClickListener() {
@Override
public void splitterClick(SplitterClickEvent event) {
getMainWindow().showNotification("Vertical Splitter Clicked");
}
});