public final class WeakInvalidationListener extends Object implements InvalidationListener, WeakListenerA
WeakInvalidationListenercan be used, if an
Observableshould 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.
WeakInvalidationListenerare created by passing in the original
WeakInvalidationListenershould then be registered to listen for changes of the observed object.
Note: You have to keep a reference to the
InvalidationListener, that was passed in as long as it is in use, otherwise it will be garbage collected to soon.
All Methods Instance Methods Concrete Methods Modifier and Type Method Description
invalidated(Observable observable)This method needs to be provided by an implementation of
trueif the linked listener was garbage-collected.
public WeakInvalidationListener(InvalidationListener listener)The constructor of
listener- The original listener that should be notified
public boolean wasGarbageCollected()Returns
trueif the linked listener was garbage-collected. In this case, the listener can be removed from the observable.
public void invalidated(Observable observable)This method needs to be provided by an implementation of
InvalidationListener. It is called if an
In general is is considered bad practice to modify the observed value in this method.