if (futureState.isClosed()) {
Dockable dockable = futureState.getDockable();
if (dockable instanceof ViewDescriptorDockable) {
ViewDescriptorDockable vdd = (ViewDescriptorDockable) dockable;
PageComponent pc = vdd.getPageComponent();
if (!pc.canClose())
event.cancel();
}
}
}