de.caff.generics

Class WeakPropertyChangeListener

java.lang.Object

de.caff.generics.WeakPropertyChangeListener

All Implemented Interfaces:

java.beans.PropertyChangeListener, java.util.EventListener

public class WeakPropertyChangeListener
extends java.lang.Object
implements java.beans.PropertyChangeListener

Wrapper for a property change listener which reference the original change listener weakly.

If the original listener is garbage collected, this property change listener is just doing nothing. Note that although the referenced listener and everything what is attached to it might be released, this listener is still attached to all classes it was added as a property change listener, because it has no chance to know where it was added, so it cannot remove itself.

Author:

Rammi

Constructor Summary

Constructors

Constructor and Description
WeakPropertyChangeListener(java.beans.PropertyChangeListener wrapped) Constructor.

Method Summary

Modifier and Type	Method and Description
boolean	isValid() Is this listener still valid?
void	propertyChange(java.beans.PropertyChangeEvent evt) This method gets called when a bound property is changed.
static void	removeWeakPropertyListener(java.beans.PropertyChangeSupport support, java.beans.PropertyChangeListener listener) Remove a weak property change listener from a property change support.
static void	removeWeakPropertyListener(java.beans.PropertyChangeSupport support, java.lang.String propertyName, java.beans.PropertyChangeListener listener) Remove a weak property change listener listening for a special property from a property change support.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

WeakPropertyChangeListener

public WeakPropertyChangeListener(@NotNull
                                  java.beans.PropertyChangeListener wrapped)

Constructor.

Parameters:

wrapped - listener to wrap, which is only hold via a weak reference

Method Detail

propertyChange

public void propertyChange(java.beans.PropertyChangeEvent evt)

This method gets called when a bound property is changed.

Specified by:

propertyChange in interface java.beans.PropertyChangeListener

Parameters:

evt - A PropertyChangeEvent object describing the event source and the property that has changed.

isValid

public boolean isValid()

Is this listener still valid?

Returns:

true if the reference is still available
false if it is no longer available

removeWeakPropertyListener

public static void removeWeakPropertyListener(@NotNull
                                              java.beans.PropertyChangeSupport support,
                                              @NotNull
                                              java.beans.PropertyChangeListener listener)

Remove a weak property change listener from a property change support. This will also remove all weak listeners where the reference is invalid.

Parameters:

support - property change support

listener - original listener wrapped by the weak listener

removeWeakPropertyListener

public static void removeWeakPropertyListener(@NotNull
                                              java.beans.PropertyChangeSupport support,
                                              @NotNull
                                              java.lang.String propertyName,
                                              @NotNull
                                              java.beans.PropertyChangeListener listener)

Remove a weak property change listener listening for a special property from a property change support. This will also remove all weak listeners where the reference is invalid.

Parameters:

support - property change support

propertyName - property name

listener - original listener wrapped by the weak listener