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.
WeakInvalidationListener is created by passing in the original
then be registered to listen for changes of the observed object.
Note: You have to keep a reference to the
was passed in as long as it is in use, otherwise it can be garbage collected
(InvalidationListener listener)The constructor of
listener- The original listener that should be notified
wasGarbageCollectedpublic boolean wasGarbageCollected()Returns
trueif the linked listener was garbage-collected. In this case, the listener can be removed from the observable.
invalidatedpublic void invalidated
(Observable observable)This method needs to be provided by an implementation of
InvalidationListener. It is called if an
In general, it is considered bad practice to modify the observed value in this method.