d.addObserver(ob);
d.setRunning(true);
Thread.sleep(idleInterval / 2);
assertTrue(d.isUserActive());
shell.notifyListeners(SWT.MouseDown, new Event());
Thread.sleep(idleInterval / 2);
assertTrue(d.isUserActive());
shell.notifyListeners(SWT.MouseDown, new Event());
Thread.sleep(idleInterval / 2);
assertTrue(d.isUserActive());
shell.notifyListeners(SWT.MouseDown, new Event());
assertEquals(0, ob.inactiveCount);
assertEquals(0, ob.activeCount);
}