com.cedarsoft.lookup

Class WeakLookupChangeListener<T>

java.lang.Object

com.cedarsoft.lookup.WeakLookupChangeListener<T>

All Implemented Interfaces:

LookupChangeListener<T>, EventListener

public class WeakLookupChangeListener<T>
extends Object
implements LookupChangeListener<T>

This listener can be used to automatically register a lookup change listener to a lookup. The listener is automatically unregistered whenever the delegating listener has been garbage collected.

Author:

Johannes Schneider (js@cedarsoft.com)

Constructor Summary

Constructors

Constructor and Description
WeakLookupChangeListener(Class<T> typeClass, LookupChangeListener<? super T> listener) Creates a new instance
WeakLookupChangeListener(LookupChangeListener<T> listener) Creates a new instance with getTypeClass() set to null

Method Summary

Modifier and Type	Method and Description
Class<T>	getTypeClass() Getter for the field typeClass.
protected LookupChangeListener<? super T>	getWrappedListener() Returns the wrapped lookup (or null if the reference has been lost
void	lookupChanged(LookupChangeEvent<? extends T> event) Is notified when the content of the lookup has been changed
static <T> WeakLookupChangeListener<T>	wrap(Class<T> type, LookupChangeListener<? super T> listener) Wraps a given lookup change listener with a weak listener
static <T> WeakLookupChangeListener<T>	wrap(LookupChangeListener<T> listener) Wraps a given lookup change listener with a weak listener

Methods inherited from class java.lang.Object

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

Constructor Detail

WeakLookupChangeListener

public WeakLookupChangeListener(@Nonnull
                                LookupChangeListener<T> listener)

Creates a new instance with getTypeClass() set to null

Parameters:

listener - the listener that is wrapped

WeakLookupChangeListener

public WeakLookupChangeListener(@Nullable
                                Class<T> typeClass,
                                @Nonnull
                                LookupChangeListener<? super T> listener)

Creates a new instance

Parameters:

typeClass - the type

listener - the listener this delegates to

Method Detail

lookupChanged

public void lookupChanged(@Nonnull
                          LookupChangeEvent<? extends T> event)

Is notified when the content of the lookup has been changed

Specified by:

lookupChanged in interface LookupChangeListener<T>

Parameters:

event - describes the change of the lookup

getWrappedListener

@Nullable
protected LookupChangeListener<? super T> getWrappedListener()

Returns the wrapped lookup (or null if the reference has been lost

Returns:

the wrapped lookup (or null if the reference has been lost

getTypeClass

@Nonnull
public Class<T> getTypeClass()

Getter for the field typeClass.

Returns:

a Class object.

wrap

public static <T> WeakLookupChangeListener<T> wrap(@Nonnull
                                                   LookupChangeListener<T> listener)

Wraps a given lookup change listener with a weak listener

Type Parameters:

T - a T object.

Parameters:

listener - the listener that is wrapped

Returns:

the weak lookup change listener that wraps the given listener

wrap

@Nonnull
public static <T> WeakLookupChangeListener<T> wrap(@Nullable
                                                            Class<T> type,
                                                            @Nonnull
                                                            LookupChangeListener<? super T> listener)

Wraps a given lookup change listener with a weak listener

Type Parameters:

T - a T object.

Parameters:

type - the type the listener is resgistered for

listener - the listener that is wrapped

Returns:

the weak lookup change listener that wraps the given listener