org.openide.util.lookup

Class AbstractLookup

java.lang.Object

org.openide.util.Lookup

org.openide.util.lookup.AbstractLookup

All Implemented Interfaces:

Serializable

public class AbstractLookup
extends Lookup
implements Serializable

Implementation of the lookup from OpenAPIs that is based on the introduction of Item. This class should provide the default way of how to store (Class, Object) pairs in the lookups. It offers protected methods for subclasses to register the pairs.

Serializable since 3.27.

Since:

1.9

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AbstractLookup.Content A class that can be used by the creator of the AbstractLookup to control its content (a kind of Privileged API giving creator of the lookup more rights than subsequent users of the lookup).
static class	AbstractLookup.Pair<T> Extension to the default lookup item that offers additional information for the data structures use in AbstractLookup

Nested classes/interfaces inherited from class org.openide.util.Lookup

Lookup.Item<T>, Lookup.Provider, Lookup.Result<T>, Lookup.Template<T>

Field Summary

Fields inherited from class org.openide.util.Lookup

EMPTY

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractLookup() Default constructor for subclasses that do not need to provide a content
	AbstractLookup(AbstractLookup.Content content) Constructor to create this lookup and associate it with given Content.

Method Summary

Modifier and Type	Method and Description
protected void	addPair(AbstractLookup.Pair<?> pair) The method to add instance to the lookup with.
protected void	addPair(AbstractLookup.Pair<?> pair, Executor notifyIn) The method to add instance to the lookup with.
protected void	beforeLookup(Lookup.Template<?> template) Notifies subclasses that a query is about to be processed.
protected void	initialize() Method for subclasses to initialize them selves.
<T> T	lookup(Class<T> clazz) Look up an object matching a given interface.
<T> Lookup.Result<T>	lookup(Lookup.Template<T> template) The general lookup method.
<T> Lookup.Item<T>	lookupItem(Lookup.Template<T> template) Look up the first item matching a given template.
protected void	removePair(AbstractLookup.Pair<?> pair) Remove instance.
protected void	removePair(AbstractLookup.Pair<?> pair, Executor notifyIn) Remove instance.
protected void	setPairs(Collection<? extends AbstractLookup.Pair> collection) Changes all pairs in the lookup to new values.
protected void	setPairs(Collection<? extends AbstractLookup.Pair> collection, Executor notifyIn) Changes all pairs in the lookup to new values, notifies listeners using provided executor.
String	toString()

Methods inherited from class org.openide.util.Lookup

getDefault, lookupAll, lookupResult

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractLookup

public AbstractLookup(AbstractLookup.Content content)

Constructor to create this lookup and associate it with given Content. The content than allows the creator to invoke protected methods which are not accessible for any other user of the lookup.

Parameters:

content - the content to assciate with

Since:

1.25

AbstractLookup

protected AbstractLookup()

Default constructor for subclasses that do not need to provide a content

Method Detail

toString

public String toString()

Overrides:

toString in class Object

initialize

protected void initialize()

Method for subclasses to initialize them selves.

beforeLookup

protected void beforeLookup(Lookup.Template<?> template)

Notifies subclasses that a query is about to be processed.

Parameters:

template - the template

addPair

protected final void addPair(AbstractLookup.Pair<?> pair)

The method to add instance to the lookup with.

Parameters:

pair - class/instance pair

addPair

protected final void addPair(AbstractLookup.Pair<?> pair,
                             Executor notifyIn)

The method to add instance to the lookup with.

Parameters:

pair - class/instance pair

notifyIn - the executor that will handle the notification of events

Since:

7.16

removePair

protected final void removePair(AbstractLookup.Pair<?> pair)

Remove instance.

Parameters:

pair - class/instance pair

removePair

protected final void removePair(AbstractLookup.Pair<?> pair,
                                Executor notifyIn)

Remove instance.

Parameters:

pair - class/instance pair

notifyIn - the executor that will handle the notification of events

Since:

7.16

setPairs

protected final void setPairs(Collection<? extends AbstractLookup.Pair> collection)

Changes all pairs in the lookup to new values.

Parameters:

collection - the collection of (Pair) objects

setPairs

protected final void setPairs(Collection<? extends AbstractLookup.Pair> collection,
                              Executor notifyIn)

Changes all pairs in the lookup to new values, notifies listeners using provided executor.

Parameters:

collection - the collection of (Pair) objects

notifyIn - the executor that will handle the notification of events

Since:

7.16

lookup

public final <T> T lookup(Class<T> clazz)

Description copied from class: Lookup

Look up an object matching a given interface. This is the simplest method to use. If more than one object matches, the first will be returned. The template class may be a class or interface; the instance is guaranteed to be assignable to it.

Specified by:

lookup in class Lookup

Parameters:

clazz - class of the object we are searching for

Returns:

an object implementing the given class or null if no such implementation is found

lookupItem

public final <T> Lookup.Item<T> lookupItem(Lookup.Template<T> template)

Description copied from class: Lookup

Look up the first item matching a given template. Includes not only the instance but other associated information.

Overrides:

lookupItem in class Lookup

Parameters:

template - the template to check

Returns:

a matching item or null

lookup

public final <T> Lookup.Result<T> lookup(Lookup.Template<T> template)

Description copied from class: Lookup

The general lookup method. Callers can get list of all instances and classes that match the given template, request more info about them in form of Lookup.Item and attach a listener to this be notified about changes. The general interface does not specify whether subsequent calls with the same template produce new instance of the Lookup.Result or return shared instance. The prefered behaviour however is to return shared one.

Specified by:

lookup in class Lookup

Parameters:

template - a template describing the services to look for

Returns:

an object containing the results