*/
WindowTracker() {
contextTracker = new ContextTracker();
long mask = WindowEvent.WINDOW_EVENT_MASK
| ComponentEvent.COMPONENT_EVENT_MASK;
new WeakAWTEventListener(contextTracker, mask);
// hold the event queue references weakly
// each queue maps to a set of components (actually a weak hash map to
// allow GC of the component keys).
contexts = new WeakHashMap();
contexts.put(Toolkit.getDefaultToolkit().getSystemEventQueue(),