- Type Parameters:
E- The type of the observed value
public final class WeakSetChangeListener<E> extends Object implements SetChangeListener<E>, WeakListenerA
WeakSetChangeListenercan be used, if an
ObservableSetshould only maintain a weak reference to the listener. This helps to avoid memory leaks, that can occur if observers are not unregistered from observed objects after use.
WeakSetChangeListenerare created by passing in the original
WeakSetChangeListenershould then be registered to listen for changes of the observed object.
Note: You have to keep a reference to the
SetChangeListener, that was passed in as long as it is in use, otherwise it will be garbage collected to soon.
public boolean wasGarbageCollected()Returns
trueif the linked listener was garbage-collected. In this case, the listener can be removed from the observable.
public void onChanged(SetChangeListener.Change<? extends E> change)Called after a change has been made to an ObservableSet. This method is called on every elementary change (add/remove) once. This means, complex changes like removeAll(Collection) or clear() may result in more than one call of onChanged method.