org.openide.util

Class Lookup.Result<T>

java.lang.Object

org.openide.util.Lookup.Result<T>

Enclosing class:

Lookup

public abstract static class Lookup.Result<T>
extends Object

Result of a lookup request. Allows access to all matching instances at once. Also permits listening to changes in the result. Result can contain duplicate items.

Constructor Summary

Constructors

Constructor and Description
Result()

Method Summary

Modifier and Type	Method and Description
abstract void	addLookupListener(LookupListener l) Registers a listener that is invoked when there is a possible change in this result.
Set<Class<? extends T>>	allClasses() Get all classes represented in the result.
abstract Collection<? extends T>	allInstances() Get all instances in the result.
Collection<? extends Lookup.Item<T>>	allItems() Get all registered items.
abstract void	removeLookupListener(LookupListener l) Unregisters a listener previously added.

Methods inherited from class java.lang.Object

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

Constructor Detail

Result

public Result()

Method Detail

addLookupListener

public abstract void addLookupListener(LookupListener l)

Registers a listener that is invoked when there is a possible change in this result.

Sometimes people report that their listener is not receiving events (for example IZ 191471) or that the listener receives few events, but then it stops listening. Such behavior is often caused by not keeping strong reference to the Lookup.Result object. When it gets garbage collected it can no longer deliver events. Thus remember to keep reference to the object you are attaching listener to.

Parameters:

l - the listener to add

removeLookupListener

public abstract void removeLookupListener(LookupListener l)

Unregisters a listener previously added.

Parameters:

l - the listener to remove

allInstances

public abstract Collection<? extends T> allInstances()

Get all instances in the result. The return value is an unmodifiable list (hence the type should be List as the order matters, but the Collection is kept for compatibility reasons) of all instances present in the Lookup.Result right now that will never change its content.

While the returned collection never changes its content, some implementation like ProxyLookup may compute the content lazily. At least once such behavior resulted in a deadlock.

Returns:

unmodifiable collection of all instances that will never change its content

allClasses

public Set<Class<? extends T>> allClasses()

Get all classes represented in the result. That is, the set of concrete classes used by instances present in the result. All duplicate classes will be omitted.

Returns:

unmodifiable set of Class objects that will never change its content

Since:

1.8

allItems

public Collection<? extends Lookup.Item<T>> allItems()

Get all registered items. This includes all pairs of instances together with their classes, IDs, and so on. The return value is an unmodifiable list (hence the type should be List as the order matters, but the Collection is kept for compatibility reasons) of all items present in the Lookup.Result right now that will never change its content.

While the returned collection never changes its content, some implementation like ProxyLookup may compute the content lazily.

Returns:

unmodifiable collection of Lookup.Item that will never change its content

Since:

1.8