org.openide.util.lookup

Class InstanceContent

java.lang.Object

org.openide.util.lookup.AbstractLookup.Content

org.openide.util.lookup.InstanceContent

All Implemented Interfaces:

Serializable

public final class InstanceContent
extends AbstractLookup.Content

A special content implementation that can be passed to AbstractLookup and provides methods for registration of instances and lazy instances.

 InstanceContent ic = new InstanceContent();
 Lookup lookup = new AbstractLookup(ic);

 ic.add(new Object ());
 ic.add(new Dimension (...));

 Dimension theDim = lookup.lookup (Dimension.class);
 

Since:

1.25

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	InstanceContent.Convertor<T,R> Convertor postpones an instantiation of an object.

Constructor Summary

Constructors

Constructor and Description
InstanceContent() Create a new, empty content.
InstanceContent(Executor notifyIn) Creates a content associated with an executor to handle dispatch of changes.

Method Summary

Modifier and Type	Method and Description
void	add(Object inst) Adds an instance to the lookup.
<T,R> void	add(T inst, InstanceContent.Convertor<T,R> conv) Adds a convertible instance into the lookup.
void	remove(Object inst) Remove instance.
<T,R> void	remove(T inst, InstanceContent.Convertor<T,R> conv) Remove instance added with a convertor.
<T,R> void	set(Collection<T> col, InstanceContent.Convertor<T,R> conv) Changes all pairs in the lookup to new values.

Methods inherited from class org.openide.util.lookup.AbstractLookup.Content

addPair, removePair, setPairs

Methods inherited from class java.lang.Object

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

Constructor Detail

InstanceContent

public InstanceContent()

Create a new, empty content.

InstanceContent

public InstanceContent(Executor notifyIn)

Creates a content associated with an executor to handle dispatch of changes.

Parameters:

notifyIn - the executor to notify changes in

Since:

7.16

Method Detail

add

public final void add(Object inst)

Adds an instance to the lookup. If inst already exists in the lookup (equality is determined by object's Object.equals(java.lang.Object) method) then the new instance replaces the old one in the lookup but listener notifications are not delivered in such case.

Parameters:

inst - instance

add

public final <T,R> void add(T inst,
                            InstanceContent.Convertor<T,R> conv)

Adds a convertible instance into the lookup. The inst argument is just a key, not the actual value to appear in the lookup. The value will be created on demand, later when it is really needed by calling convertor methods.

This method is useful to delay creation of heavy weight objects. Instead just register lightweight key and a convertor.

To remove registered object from lookup use InstanceContent.remove(java.lang.Object, org.openide.util.lookup.InstanceContent.Convertor) with the same arguments.

Type Parameters:

T - type of instance

R - type to convert instance to

Parameters:

inst - instance

conv - convertor which postponing an instantiation, if conv==null then the instance is registered directly.

remove

public final void remove(Object inst)

Remove instance.

Parameters:

inst - instance

remove

public final <T,R> void remove(T inst,
                               InstanceContent.Convertor<T,R> conv)

Remove instance added with a convertor.

Type Parameters:

T - type of instance

R - type to convert instance to

Parameters:

inst - instance

conv - convertor, if conv==null it is same like remove(Object)

set

public final <T,R> void set(Collection<T> col,
                            InstanceContent.Convertor<T,R> conv)

Changes all pairs in the lookup to new values. Converts collection of instances to collection of pairs.

Type Parameters:

T - type of instance

R - type to convert instance to

Parameters:

col - the collection of (Item) objects

conv - the convertor to use or null