VBoxLayoutData contentVBoxData = new VBoxLayoutData();
contentVBoxData.setFlex(2);
tab.add(contentContainer, contentVBoxData);
listView.addListener(Events.DoubleClick, new Listener<ListViewEvent<GWTJahiaNode>>() {
public void handleEvent(ListViewEvent<GWTJahiaNode> be) {
Window w = new Window();
GWTJahiaNode node = listView.getSelectionModel().getSelectedItem();
final String text = "Preview of " + node.getDisplayName();