org.openide.util.lookup

Class ProxyLookup

java.lang.Object

org.openide.util.Lookup

org.openide.util.lookup.ProxyLookup

public class ProxyLookup
extends Lookup

Implementation of lookup that can delegate to others.

Since:

1.9

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ProxyLookup.Controller A controller which allows the set of lookups being proxied to be set dynamically for those who create the instance of ProxyLookup.

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	ProxyLookup() Create a lookup initially proxying to no others.
	ProxyLookup(Lookup... lookups) Create a proxy to some other lookups.
	ProxyLookup(ProxyLookup.Controller controller) Create a ProxyLookup whose contents can be set dynamically subclassing.

Method Summary

Modifier and Type	Method and Description
protected void	beforeLookup(Lookup.Template<?> template) Notifies subclasses that a query is about to be processed.
protected Lookup[]	getLookups() Getter for the delegates.
<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	setLookups(Executor notifyIn, Lookup... lookups) Changes the delegates immediatelly, notifies the listeners in provided executor, potentially later.
protected void	setLookups(Lookup... lookups) Changes the delegates.
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

ProxyLookup

public ProxyLookup(Lookup... lookups)

Create a proxy to some other lookups.

Parameters:

lookups - the initial delegates

ProxyLookup

public ProxyLookup(ProxyLookup.Controller controller)

Create a ProxyLookup whose contents can be set dynamically subclassing. The passed ProxyLookup.Controller can be later be used to call ProxyLookup.Controller.setLookups(java.util.concurrent.Executor, org.openide.util.Lookup...) which then changes the lookups this ProxyLookup delegates to. The passed controller may only be used for one ProxyLookup.

Parameters:

controller - A ProxyLookup.Controller which can be used to set the lookups

Throws:

IllegalStateException - if the passed controller has already been attached to another ProxyLookup

Since:

8.43

ProxyLookup

protected ProxyLookup()

Create a lookup initially proxying to no others. Permits serializable subclasses.

Since:

3.27

Method Detail

toString

public String toString()

Overrides:

toString in class Object

getLookups

protected final Lookup[] getLookups()

Getter for the delegates.

Returns:

the array of lookups we delegate to

Since:

1.19

setLookups

protected final void setLookups(Lookup... lookups)

Changes the delegates.

Parameters:

lookups - the new lookups to delegate to

Since:

1.19 protected

setLookups

protected final void setLookups(Executor notifyIn,
                                Lookup... lookups)

Changes the delegates immediatelly, notifies the listeners in provided executor, potentially later.

Parameters:

lookups - the new lookups to delegate to

notifyIn - executor to deliver the notification to listeners or null

Since:

7.16

beforeLookup

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

Notifies subclasses that a query is about to be processed. Subclasses can update its state before the actual processing begins. It is allowed to call setLookups method to change/update the set of objects the proxy delegates to.

Parameters:

template - the template of the query

Since:

1.31

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