T- The type of the observed value
public final class WeakChangeListener<T> extends Object implements ChangeListener<T>, WeakListener
WeakChangeListenercan be used, if an
ObservableValueshould 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.
WeakChangeListener are created by passing in the original
WeakChangeListener should 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 will be garbage collected
|Constructor and Description|
The constructor of
|Modifier and Type||Method and Description|
This method needs to be provided by an implementation of
public WeakChangeListener(ChangeListener<T> listener)
listener- The original listener that should be notified
public boolean wasGarbageCollected()
trueif the linked listener was garbage-collected. In this case, the listener can be removed from the observable.
trueif the linked listener was garbage-collected.
public void changed(ObservableValue<? extends T> observable, T oldValue, T newValue)
ChangeListener. It is called if the value of an
In general is is considered bad practice to modify the observed value in this method.
ObservableValuewhich value changed
oldValue- The old value
newValue- The new value
Copyright (c) 2008, 2015, Oracle and/or its affiliates. All rights reserved.