public abstract class ObservableValueBase<T> extends java.lang.Object implements ObservableValue<T>
ObservableValue
.
It contains all of the infrastructure support for value invalidation- and
change event notification.
This implementation can handle adding and removing listeners while the
observers are being notified, but it is not thread-safe.Modifier and Type | Field and Description |
---|---|
private <any> |
helper |
Constructor and Description |
---|
ObservableValueBase() |
Modifier and Type | Method and Description |
---|---|
void |
addListener(InvalidationListener listener)
Adds a
ChangeListener which will be notified whenever the value
of the ObservableValue changes. |
protected void |
fireValueChangedEvent()
Notify the currently registered observers of a value change.
|
void |
removeListener(InvalidationListener listener)
Removes the given listener from the list of listeners that are notified
whenever the value of the
ObservableValue changes. |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
getValue
public void addListener(InvalidationListener listener)
ChangeListener
which will be notified whenever the value
of the ObservableValue
changes. If the same listener is added
more than once, then it will be notified more than once. That is, no
check is made to ensure uniqueness.
Note that the same actual ChangeListener
instance may be safely
registered for different ObservableValues
.
The ObservableValue
stores a strong reference to the listener
which will prevent the listener from being garbage collected and may
result in a memory leak. It is recommended to either unregister a
listener by calling removeListener
after use or to use an instance of
WeakChangeListener
avoid this situation.
addListener
in interface ObservableValue<T>
listener
- The listener to registerObservableValue.removeListener(ChangeListener)
public void removeListener(InvalidationListener listener)
ObservableValue
changes.
If the given listener has not been previously registered (i.e. it was never added) then this method call is a no-op. If it had been previously added then it will be removed. If it had been added more than once, then only the first occurrence will be removed.
removeListener
in interface ObservableValue<T>
listener
- The listener to removeObservableValue.addListener(ChangeListener)
protected void fireValueChangedEvent()