Spec-Zone .ru
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public final class WeakInvalidationListener extends java.lang.Object implements InvalidationListener
WeakInvalidationListener
can be used, if an ObservableValue
should 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
are created by passing in the original
InvalidationListener
. The WeakInvalidationListener
should
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.
ChangeListener
,
ObservableValue
Constructor and Description |
---|
WeakInvalidationListener(InvalidationListener listener)
The constructor of
WeakInvalidationListener . |
Modifier and Type | Method and Description |
---|---|
void |
invalidated(Observable observable)
This method needs to be provided by an implementation of
InvalidationListener . |
boolean |
wasGarbageCollected()
Returns
true if the linked InvalidationListener was
garbage-collected. |
public WeakInvalidationListener(InvalidationListener listener)
WeakInvalidationListener
.listener
- The original listener that should be notifiedpublic boolean wasGarbageCollected()
true
if the linked InvalidationListener
was
garbage-collected. In this case, the listener can be removed from the
observable.true
if the linked InvalidationListener
was
garbage-collected.public void invalidated(Observable observable)
InvalidationListener
InvalidationListener
. It is called if an ObservableValue
becomes invalid.
In general is is considered bad practice to modify the observed value in this method.
invalidated
in interface InvalidationListener
observable
- The ObservableValue
that became invalidCopyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved. Use is subject to