T
- The type of the short-lived objectpublic abstract class ALcdWeakPropertyChangeListener<T> extends Object implements PropertyChangeListener
A PropertyChangeListener
implementation which only keeps a WeakReference
to the object it
wants to update when property changes are received. This avoids memory leaks, even without removing the
listener.
The class javadoc of ALcdWeakModelListener
contains an example of a weak listener,
and some rules on the usage of weak listeners.
This particular listener has two extra rules compared to the general rules of weak listeners:
ILcdPropertyChangeSource
.addPropertyChangeListener(String, ...)
ILcdPropertyChangeSource
Modifier | Constructor and Description |
---|---|
protected |
ALcdWeakPropertyChangeListener(T aObjectToModify)
Creates a new
ALcdWeakPropertyChangeListener instance which can update aObjectToModify
when it receives events. |
Modifier and Type | Method and Description |
---|---|
void |
propertyChange(PropertyChangeEvent evt) |
protected abstract void |
propertyChangeImpl(T aToModify,
PropertyChangeEvent aPropertyChangeEvent)
This method is called each time a
PropertyChangeEvent is received by this listener,
and the short-living object to modify passed in the constructor of this listener is not yet GC-ed. |
protected ALcdWeakPropertyChangeListener(T aObjectToModify)
Creates a new ALcdWeakPropertyChangeListener
instance which can update aObjectToModify
when it receives events.
Warning: this listener can only be registered to a ILcdPropertyChangeSource
.
The listener will throw exceptions when it receives PropertyChangeEvent
instances where the source is not
an ILcdPropertyChangeSource
instance.
aObjectToModify
- The object you want to modify when a PropertyChangeEvent
is received.
This is a short-lived object, while the listener will be attached to a
long-living ILcdPropertyChangeSource
object.public final void propertyChange(PropertyChangeEvent evt)
This method will check whether the short-living object is still available.
If it is, this method will pass the short-living object and the event to the propertyChangeImpl(Object, java.beans.PropertyChangeEvent)
method.
If the short-living object is already garbage collected, this method will de-register the listener from the source.
propertyChange
in interface PropertyChangeListener
propertyChangeImpl(Object, java.beans.PropertyChangeEvent)
protected abstract void propertyChangeImpl(T aToModify, PropertyChangeEvent aPropertyChangeEvent)
This method is called each time a PropertyChangeEvent
is received by this listener,
and the short-living object to modify passed in the constructor of this listener is not yet GC-ed.
aToModify
- The object to modify, as passed in the constructor of this class.aPropertyChangeEvent
- The received event