final HorizontalSplitPanel hsplit = new HorizontalSplitPanel();
hsplit.setSizeFull();
hsplit.setImmediate(true);
hsplit.setSplitPosition(100, Sizeable.UNITS_PIXELS, hsplitReversed);
hsplit.addListener(new HorizontalSplitPanel.SplitterClickListener() {
@Override
public void splitterClick(SplitterClickEvent event) {
getMainWindow().showNotification("Horizontal Splitter Clicked");
}
});