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

Author:

Jaroslav Tulach

Nested Class Summary

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.

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() Returns a string representation of the object.

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

protected ProxyLookup()

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

Since:

3.27

Method Detail

toString

public String toString()

Description copied from class: Object

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 getClass().getName() + '@' + Integer.toHexString(hashCode())
 

Overrides:

toString in class Object

Returns:

a string representation of the 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