http://www.eclipse.org/platform: Extension Registry Support (Eclipse Foundation) 
Copyright (c) 2003, 2014 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation

/*******************************************************************************
 * Copyright (c) 2003, 2014 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.core.runtime;

import java.io.InputStream;
import java.util.ResourceBundle;


The extension registry holds the master list of all
discovered namespaces, extension points and extensions.


The extension registry can be queried, by name, for
extension points and extensions.



 The various objects that describe the contents of the extension registry (IExtensionPoint, IExtension, and IConfigurationElement) are intended for relatively short-term use. Clients that deal with these objects must be aware that they may become invalid if the declaring plug-in is updated or uninstalled. If this happens, all methods on these object except isValid() will throw InvalidRegistryObjectException. Code in a plug-in that has declared that it is not dynamic aware (or not declared anything) can safely ignore this issue, since the registry would not be modified while it is active. However, code in a plug-in that declares that it is dynamic aware must be careful if it accesses extension registry objects, because it's at risk if plug-in are removed. Similarly, tools that analyze or display the extension registry are vulnerable. Client code can pre-test for invalid objects by calling isValid(), which never throws this exception.
However, pre-tests are usually not sufficient because of the possibility of the
extension registry object becoming invalid as a result of a concurrent activity.
At-risk clients must treat InvalidRegistryObjectException as if it
were a checked exception. Also, such clients should probably register a listener
with the extension registry so that they receive notification of any changes to
the registry.




Extensions and extension points are declared by generic entities called
namespaces. The only fact known about namespaces is that they
have unique string-based identifiers. One example of a namespace
is a plug-in, for which the namespace id is the plug-in id.


This interface can be used without OSGi running.


This interface is not intended to be implemented by clients.



Since:3.0
@noimplementThis interface is not intended to be implemented by clients.
/**
 * The extension registry holds the master list of all
 * discovered namespaces, extension points and extensions.
 * <p>
 * The extension registry can be queried, by name, for
 * extension points and extensions.
 * </p>
 * <p>
 * The various objects that describe the contents of the extension registry
 * ({@link IExtensionPoint}, {@link IExtension}, and {@link IConfigurationElement})
 * are intended for relatively short-term use. Clients that deal with these objects
 * must be aware that they may become invalid if the declaring plug-in is updated
 * or uninstalled. If this happens, all methods on these object except
 * <code>isValid()</code> will throw {@link org.eclipse.core.runtime.InvalidRegistryObjectException}.
 * Code in a plug-in that has declared that it is not dynamic aware (or not declared
 * anything) can safely ignore this issue, since the registry would not be
 * modified while it is active. However, code in a plug-in that declares that it
 * is dynamic aware must be careful if it accesses extension registry objects,
 * because it's at risk if plug-in are removed. Similarly, tools that analyze
 * or display the extension registry are vulnerable. Client code can pre-test for
 * invalid objects by calling <code>isValid()</code>, which never throws this exception.
 * However, pre-tests are usually not sufficient because of the possibility of the
 * extension registry object becoming invalid as a result of a concurrent activity.
 * At-risk clients must treat <code>InvalidRegistryObjectException</code> as if it
 * were a checked exception. Also, such clients should probably register a listener
 * with the extension registry so that they receive notification of any changes to
 * the registry.
 * </p>
 * <p>
 * Extensions and extension points are declared by generic entities called
 * <cite>namespaces</cite>. The only fact known about namespaces is that they
 * have unique string-based identifiers. One example of a namespace
 * is a plug-in, for which the namespace id is the plug-in id.
 * </p><p>
 * This interface can be used without OSGi running.
 * </p><p>
 * This interface is not intended to be implemented by clients.
 * </p>
 * @since 3.0
 * @noimplement This interface is not intended to be implemented by clients.
 */
public interface IExtensionRegistry {
	
Note: for new implementations consider using addListener(IRegistryEventListener, String). 

Adds the given listener for registry change events related to extension points
in the given namespace.
Has no effect if an identical listener is already registered. After
completion of this method, the given listener will be registered for events
related to extension points in the specified namespace. If no namespace
is specified, the listener will receive notifications for changes to
extension points in any namespace.


Once registered, a listener starts receiving notification of changes to
 the registry. Registry change notifications are sent asynchronously.
The listener continues to receive notifications until it is removed.



Params:
  • listener – the listener
  • namespace – the namespace in which to listen for changes
See Also:
/**
	 * <b>Note:</b> for new implementations consider using {@link #addListener(IRegistryEventListener, String)}.
	 * <p>
	 * Adds the given listener for registry change events related to extension points
	 * in the given namespace.
	 * Has no effect if an identical listener is already registered. After
	 * completion of this method, the given listener will be registered for events
	 * related to extension points in the specified namespace. If no namespace
	 * is specified, the listener will receive notifications for changes to
	 * extension points in any namespace.
	 * </p><p>
	 * Once registered, a listener starts receiving notification of changes to
	 *  the registry. Registry change notifications are sent asynchronously.
	 * The listener continues to receive notifications until it is removed.
	 * </p>
	 * @param listener the listener
	 * @param namespace the namespace in which to listen for changes
	 * @see IRegistryChangeListener
	 * @see IRegistryChangeEvent
	 * @see #removeRegistryChangeListener(IRegistryChangeListener)
	 */
	public void addRegistryChangeListener(IRegistryChangeListener listener, String namespace);

	
Note: for new implementations consider using addListener(IRegistryEventListener). 

Adds the given listener for registry change events.
Has no effect if an identical listener is already registered.


This method is equivalent to:



    addRegistryChangeListener(listener,null);



Params:
  • listener – the listener
See Also:
/**
	 * <b>Note:</b> for new implementations consider using {@link #addListener(IRegistryEventListener)}.
	 * <p>
	 * Adds the given listener for registry change events.
	 * Has no effect if an identical listener is already registered.
	 *
	 * </p><p>
	 * This method is equivalent to:
	 * </p>
	 * <pre>
	 *     addRegistryChangeListener(listener,null);
	 * </pre>
	 *
	 * @param listener the listener
	 * @see IRegistryChangeListener
	 * @see IRegistryChangeEvent
	 * @see #addRegistryChangeListener(IRegistryChangeListener, String)
	 * @see #removeRegistryChangeListener(IRegistryChangeListener)
	 */
	public void addRegistryChangeListener(IRegistryChangeListener listener);

	
Returns all configuration elements from all extensions configured
into the identified extension point. Returns an empty array if the extension
point does not exist, has no extensions configured, or none of the extensions
contain configuration elements.

Params:
  • extensionPointId – the unique identifier of the extension point
	(e.g. "org.eclipse.core.resources.builders")
Returns:the configuration elements
/**
	 * Returns all configuration elements from all extensions configured
	 * into the identified extension point. Returns an empty array if the extension
	 * point does not exist, has no extensions configured, or none of the extensions
	 * contain configuration elements.
	 *
	 * @param extensionPointId the unique identifier of the extension point
	 *		(e.g. <code>"org.eclipse.core.resources.builders"</code>)
	 * @return the configuration elements
	 */
	public IConfigurationElement[] getConfigurationElementsFor(String extensionPointId);

	
Returns all configuration elements from all extensions configured
into the identified extension point. Returns an empty array if the extension
point does not exist, has no extensions configured, or none of the extensions
contain configuration elements.

Params:
  • namespace – the namespace for the extension point
	(e.g. "org.eclipse.core.resources")
  • extensionPointName – the simple identifier of the
	extension point (e.g. "builders")
Returns:the configuration elements
/**
	 * Returns all configuration elements from all extensions configured
	 * into the identified extension point. Returns an empty array if the extension
	 * point does not exist, has no extensions configured, or none of the extensions
	 * contain configuration elements.
	 *
	 * @param namespace the namespace for the extension point
	 *		(e.g. <code>"org.eclipse.core.resources"</code>)
	 * @param extensionPointName the simple identifier of the
	 *		extension point (e.g. <code>"builders"</code>)
	 * @return the configuration elements
	 */
	public IConfigurationElement[] getConfigurationElementsFor(String namespace, String extensionPointName);

	
Returns all configuration elements from the identified extension.
Returns an empty array if the extension does not exist or
contains no configuration elements.

Params:
  • namespace – the namespace for the extension point
	(e.g. "org.eclipse.core.resources")
  • extensionPointName – the simple identifier of the
	extension point (e.g. "builders")
  • extensionId – the unique identifier of the extension
	(e.g. "com.example.acme.coolbuilder")
Returns:the configuration elements
/**
	 * Returns all configuration elements from the identified extension.
	 * Returns an empty array if the extension does not exist or
	 * contains no configuration elements.
	 *
	 * @param namespace the namespace for the extension point
	 *		(e.g. <code>"org.eclipse.core.resources"</code>)
	 * @param extensionPointName the simple identifier of the
	 *		extension point (e.g. <code>"builders"</code>)
	 * @param extensionId the unique identifier of the extension
	 *		(e.g. <code>"com.example.acme.coolbuilder"</code>)
	 * @return the configuration elements
	 */
	public IConfigurationElement[] getConfigurationElementsFor(String namespace, String extensionPointName, String extensionId);

	
Returns the specified extension in this extension registry,
or null if there is no such extension.

Params:
  • extensionId – the unique identifier of the extension
	(e.g. "com.example.acme.coolbuilder")
Returns:the extension, or null
/**
	 * Returns the specified extension in this extension registry,
	 * or <code>null</code> if there is no such extension.
	 *
	 * @param extensionId the unique identifier of the extension
	 *		(e.g. <code>"com.example.acme.coolbuilder"</code>)
	 * @return the extension, or <code>null</code>
	 */
	public IExtension getExtension(String extensionId);

	
Returns the specified extension in this extension registry,
or null if there is no such extension.
The first parameter identifies the extension point, and the second
parameter identifies an extension plugged in to that extension point.

Params:
  • extensionPointId – the unique identifier of the extension point
	(e.g. "org.eclipse.core.resources.builders")
  • extensionId – the unique identifier of the extension
	(e.g. "com.example.acme.coolbuilder")
Returns:the extension, or null
/**
	 * Returns the specified extension in this extension registry,
	 * or <code>null</code> if there is no such extension.
	 * The first parameter identifies the extension point, and the second
	 * parameter identifies an extension plugged in to that extension point.
	 *
	 * @param extensionPointId the unique identifier of the extension point
	 *		(e.g. <code>"org.eclipse.core.resources.builders"</code>)
	 * @param extensionId the unique identifier of the extension
	 *		(e.g. <code>"com.example.acme.coolbuilder"</code>)
	 * @return the extension, or <code>null</code>
	 */
	public IExtension getExtension(String extensionPointId, String extensionId);

	
Returns the specified extension in this extension registry,
or null if there is no such extension.
The first two parameters identify the extension point, and the third
parameter identifies an extension plugged in to that extension point.

Params:
  • namespace – the namespace for the extension point
	(e.g. "org.eclipse.core.resources")
  • extensionPointName – the simple identifier of the
	extension point (e.g. "builders")
  • extensionId – the unique identifier of the extension
	(e.g. "com.example.acme.coolbuilder")
Returns:the extension, or null
/**
	 * Returns the specified extension in this extension registry,
	 * or <code>null</code> if there is no such extension.
	 * The first two parameters identify the extension point, and the third
	 * parameter identifies an extension plugged in to that extension point.
	 *
	 * @param namespace the namespace for the extension point
	 *		(e.g. <code>"org.eclipse.core.resources"</code>)
	 * @param extensionPointName the simple identifier of the
	 *		extension point (e.g. <code>"builders"</code>)
	 * @param extensionId the unique identifier of the extension
	 *		(e.g. <code>"com.example.acme.coolbuilder"</code>)
	 * @return the extension, or <code>null</code>
	 */
	public IExtension getExtension(String namespace, String extensionPointName, String extensionId);

	
Returns the extension point with the given extension point identifier
in this extension registry, or null if there is no such
extension point.

Params:
  • extensionPointId – the unique identifier of the extension point
   (e.g., "org.eclipse.core.resources.builders")
Returns:the extension point, or null
/**
	 * Returns the extension point with the given extension point identifier
	 * in this extension registry, or <code>null</code> if there is no such
	 * extension point.
	 *
	 * @param extensionPointId the unique identifier of the extension point
	 *    (e.g., <code>"org.eclipse.core.resources.builders"</code>)
	 * @return the extension point, or <code>null</code>
	 */
	public IExtensionPoint getExtensionPoint(String extensionPointId);

	
Returns the extension point in this extension registry
with the given namespace and extension point simple identifier,
or null if there is no such extension point.

Params:
  • namespace – the namespace for the given extension point
	(e.g. "org.eclipse.core.resources")
  • extensionPointName – the simple identifier of the
	extension point (e.g. "builders")
Returns:the extension point, or null
/**
	 * Returns the extension point in this extension registry
	 * with the given namespace and extension point simple identifier,
	 * or <code>null</code> if there is no such extension point.
	 *
	 * @param namespace the namespace for the given extension point
	 *		(e.g. <code>"org.eclipse.core.resources"</code>)
	 * @param extensionPointName the simple identifier of the
	 *		extension point (e.g. <code>"builders"</code>)
	 * @return the extension point, or <code>null</code>
	 */
	public IExtensionPoint getExtensionPoint(String namespace, String extensionPointName);

	
Returns all extension points known to this extension registry.
Returns an empty array if there are no extension points.

Returns:the extension points known to this extension registry
/**
	 * Returns all extension points known to this extension registry.
	 * Returns an empty array if there are no extension points.
	 *
	 * @return the extension points known to this extension registry
	 */
	public IExtensionPoint[] getExtensionPoints();

	
Returns all extension points declared in the given namespace. Returns an empty array if
there are no extension points declared in the namespace.

Params:
  • namespace – the namespace for the extension points
	(e.g. "org.eclipse.core.resources")
Returns:the extension points in this registry declared in the given namespace
/**
	 * Returns all extension points declared in the given namespace. Returns an empty array if
	 * there are no extension points declared in the namespace.
	 *
	 * @param namespace the namespace for the extension points
	 *		(e.g. <code>"org.eclipse.core.resources"</code>)
	 * @return the extension points in this registry declared in the given namespace
	 */
	public IExtensionPoint[] getExtensionPoints(String namespace);

	
Returns all extension points supplied by the contributor, or null
if there are no such extension points.

Params:
  • contributor – the contributor for the extensions (for OSGi registry, bundles and
fragments are different contributors)
Returns:the extension points, or null
Since:3.4
/**
	 * Returns all extension points supplied by the contributor, or <code>null</code>
	 * if there are no such extension points.
	 *
	 * @param contributor the contributor for the extensions (for OSGi registry, bundles and
	 * fragments are different contributors)
	 * @return the extension points, or <code>null</code>
	 * @since 3.4
	 */
	public IExtensionPoint[] getExtensionPoints(IContributor contributor);

	
Returns all extensions declared in the given namespace. Returns an empty array if
no extensions are declared in the namespace.

Params:
  • namespace – the namespace for the extensions
	(e.g. "org.eclipse.core.resources")
Returns:the extensions in this registry declared in the given namespace
/**
	 * Returns all extensions declared in the given namespace. Returns an empty array if
	 * no extensions are declared in the namespace.
	 *
	 * @param namespace the namespace for the extensions
	 *		(e.g. <code>"org.eclipse.core.resources"</code>)
	 * @return the extensions in this registry declared in the given namespace
	 */
	public IExtension[] getExtensions(String namespace);

	
Returns all extensions supplied by the contributor, or null if there
are no such extensions.

Params:
  • contributor – the contributor for the extensions (for OSGi registry, bundles and
fragments are different contributors)
Returns:the extensions, or null
Since:3.4
/**
	 * Returns all extensions supplied by the contributor, or <code>null</code> if there
	 * are no such extensions.
	 * @param contributor the contributor for the extensions (for OSGi registry, bundles and
	 * fragments are different contributors)
	 * @return the extensions, or <code>null</code>
	 * @since 3.4
	 */
	public IExtension[] getExtensions(IContributor contributor);

	
Returns all namespaces currently used by extensions and extension points in this
registry. Returns an empty array if there are no known extensions/extension points
in this registry.


The fully-qualified name of an extension point or an extension consist of
a namespace and a simple name (much like a qualified Java class name consist
of a package name and a class name). The simple names are presumed to be unique
in the namespace.



Returns:all namespaces known to this registry
/**
	 * Returns all namespaces currently used by extensions and extension points in this
	 * registry. Returns an empty array if there are no known extensions/extension points
	 * in this registry.
	 * <p>
	 * The fully-qualified name of an extension point or an extension consist of
	 * a namespace and a simple name (much like a qualified Java class name consist
	 * of a package name and a class name). The simple names are presumed to be unique
	 * in the namespace.
	 * </p>
	 * @return all namespaces known to this registry
	 */
	public String[] getNamespaces();

	
Removes the given registry change listener from this registry.
Has no effect if an identical listener is not registered.

Params:
  • listener – the listener
See Also:
/**
	 * Removes the given registry change listener from this registry.
	 * Has no effect if an identical listener is not registered.
	 *
	 * @param listener the listener
	 * @see IRegistryChangeListener
	 * @see #addRegistryChangeListener(IRegistryChangeListener)
	 * @see #addRegistryChangeListener(IRegistryChangeListener, String)
	 */
	public void removeRegistryChangeListener(IRegistryChangeListener listener);

	
Adds to this extension registry an extension point(s), extension(s), or
a combination of those described by the XML file. The information in
the XML file should be supplied in the same format as the plugin.xml; in fact,
Plug-in Manifest editor can be used to prepare the XML file. The top token
of the contribution (normally, "plugin" or "fragment" in the Plug-in Manifest
editor) is ignored by this method.

 This method is an access controlled method. Proper token (master token or user token) should be passed as an argument. Two registry keys are set in the registry constructor RegistryFactory.createRegistry(RegistryStrategy, Object, Object): master token and a user token. Master token allows all operations; user token allows non-persisted registry elements to be modified. 


Params:
  • is – stream open on the XML file. The XML file can contain an extension
point(s) or/and extension(s) described in the format similar to plugin.xml. The method
closes  the stream before returning
  • contributor – the contributor making this contribution.
  • persist – indicates if the contribution(s) should be stored in the registry cache. If false,
	contribution is not persisted in the registry cache and is lost on Eclipse restart
  • name – optional name of the contribution. Used for error reporting; might be null
  • translationBundle – optional resource bundle used for translations; might be null
  • token – the key used to check permissions
Throws:
See Also:
Returns:true if the contribution was successfully processed and false
	otherwise
Since:org.eclipse.equinox.registry 3.2
/**
	 * Adds to this extension registry an extension point(s), extension(s), or
	 * a combination of those described by the XML file. The information in
	 * the XML file should be supplied in the same format as the plugin.xml; in fact,
	 * Plug-in Manifest editor can be used to prepare the XML file. The top token
	 * of the contribution (normally, "plugin" or "fragment" in the Plug-in Manifest
	 * editor) is ignored by this method.
	 * <p>
	 * This method is an access controlled method. Proper token (master token or user token) should
	 * be passed as an argument. Two registry keys are set in the registry constructor
	 * {@link RegistryFactory#createRegistry(org.eclipse.core.runtime.spi.RegistryStrategy, Object, Object)}:
	 * master token and a user token. Master token allows all operations; user token allows
	 * non-persisted registry elements to be modified.
	 * </p>
	 * @param is stream open on the XML file. The XML file can contain an extension
	 * point(s) or/and extension(s) described in the format similar to plugin.xml. The method
	 * closes  the stream before returning
	 * @param contributor the contributor making this contribution.
	 * @param persist indicates if the contribution(s) should be stored in the registry cache. If <code>false</code>,
	 * 	contribution is not persisted in the registry cache and is lost on Eclipse restart
	 * @param name optional name of the contribution. Used for error reporting; might be <code>null</code>
	 * @param translationBundle optional resource bundle used for translations; might be <code>null</code>
	 * @param token the key used to check permissions
	 * @return <code>true</code> if the contribution was successfully processed and <code>false</code>
	 * 	otherwise
	 * @throws IllegalArgumentException if an incorrect token is passed
	 *
	 * @see IContributor
	 * @since org.eclipse.equinox.registry 3.2
	 */
	public boolean addContribution(InputStream is, IContributor contributor, boolean persist, String name, ResourceBundle translationBundle, Object token) throws IllegalArgumentException;

	
Removes the given extension from this registry.

 This method is an access controlled method. Proper token (master token or user token) should be passed as an argument. Two registry keys are set in the registry constructor RegistryFactory.createRegistry(RegistryStrategy, Object, Object): master token and a user token. Master token allows all operations; user token only allows non-persisted registry elements to be modified. 


Params:
  • extension – extension to be removed
  • token – the key used to check permissions
Throws:
Returns:true if the extension was successfully removed, and false otherwise
Since:org.eclipse.equinox.registry 3.2
/**
	 * Removes the given extension from this registry.
	 * <p>
	 * This method is an access controlled method. Proper token (master token or user token) should
	 * be passed as an argument. Two registry keys are set in the registry constructor
	 * {@link RegistryFactory#createRegistry(org.eclipse.core.runtime.spi.RegistryStrategy, Object, Object)}:
	 * master token and a user token. Master token allows all operations; user token only
	 * allows non-persisted registry elements to be modified.
	 * </p>
	 * @param extension extension to be removed
	 * @param token the key used to check permissions
	 * @return <code>true</code> if the extension was successfully removed, and <code>false</code> otherwise
	 * @throws IllegalArgumentException if an incorrect token is passed
	 *
	 * @since org.eclipse.equinox.registry 3.2
	 */
	public boolean removeExtension(IExtension extension, Object token) throws IllegalArgumentException;

	
Removes the specified extension point from this registry.

 This method is an access controlled method. Proper token (master token or user token) should be passed as an argument. Two registry keys are set in the registry constructor RegistryFactory.createRegistry(RegistryStrategy, Object, Object): master token and a user token. Master token allows all operations; user token only allows non-persisted registry elements to be modified. 


Params:
  • extensionPoint – extension point to be removed
  • token – the key used to check permissions
Throws:
Returns:true if the extension point was successfully removed, and
	false otherwise
Since:org.eclipse.equinox.registry 3.2
/**
	 * Removes the specified extension point from this registry.
	 * <p>
	 * This method is an access controlled method. Proper token (master token or user token) should
	 * be passed as an argument. Two registry keys are set in the registry constructor
	 * {@link RegistryFactory#createRegistry(org.eclipse.core.runtime.spi.RegistryStrategy, Object, Object)}:
	 * master token and a user token. Master token allows all operations; user token only
	 * allows non-persisted registry elements to be modified.
	 * </p>
	 * @param extensionPoint extension point to be removed
	 * @param token the key used to check permissions
	 * @return <code>true</code> if the extension point was successfully removed, and
	 * 	<code>false</code> otherwise
	 * @throws IllegalArgumentException if incorrect token is passed
	 *
	 * @since org.eclipse.equinox.registry 3.2
	 */
	public boolean removeExtensionPoint(IExtensionPoint extensionPoint, Object token) throws IllegalArgumentException;

	
Call this method to properly stop the registry. The method stops registry event processing
and writes out cache information to be used in the next run. This is an access controlled
method; master token is required.


This method is an access controlled method. Master token should be passed as an argument.



Params:
  • token – master token for the registry
Throws:
See Also:
  • createRegistry.createRegistry(RegistryStrategy, Object, Object)
Since:org.eclipse.equinox.registry 3.2
/**
	 * Call this method to properly stop the registry. The method stops registry event processing
	 * and writes out cache information to be used in the next run. This is an access controlled
	 * method; master token is required.
	 * <p>
	 * This method is an access controlled method. Master token should be passed as an argument.
	 * </p>
	 * @see RegistryFactory#createRegistry(org.eclipse.core.runtime.spi.RegistryStrategy, Object, Object)
	 * @param token master token for the registry
	 * @throws IllegalArgumentException if incorrect token is passed
	 *
	 * @since org.eclipse.equinox.registry 3.2
	 */
	public void stop(Object token) throws IllegalArgumentException;

	
Adds the given listener for registry change events. Listener will be notified
on changes to all extension points and underlying extensions.


Depending on activity, listeners of this type might receive a large number
of modifications and negatively impact overall system performance. Whenever
possible, consider registering listener specific to an extension point rather
than a "global" listener.


Once registered, a listener starts receiving notification of changes to
the registry. Registry change notifications are sent asynchronously.
The listener continues to receive notifications until it is removed.


This method has no effect if the listener is already registered.



Params:
  • listener – the listener
Since:org.eclipse.equinox.registry 3.4
/**
	 * Adds the given listener for registry change events. Listener will be notified
	 * on changes to all extension points and underlying extensions.
	 * <p>
	 * Depending on activity, listeners of this type might receive a large number
	 * of modifications and negatively impact overall system performance. Whenever
	 * possible, consider registering listener specific to an extension point rather
	 * than a "global" listener.
	 * </p><p>
	 * Once registered, a listener starts receiving notification of changes to
	 * the registry. Registry change notifications are sent asynchronously.
	 * The listener continues to receive notifications until it is removed.
	 * </p><p>
	 * This method has no effect if the listener is already registered.
	 * </p>
	 * @param listener the listener
	 * @since org.eclipse.equinox.registry 3.4
	 */
	public void addListener(IRegistryEventListener listener);

	
Adds the given listener for registry change events related to specified
extension point.


Once registered, a listener starts receiving notification of changes to
the registry. Registry change notifications are sent asynchronously.
The listener continues to receive notifications until it is removed.


This method has no effect if the listener is already registered.



Params:
  • listener – the listener
  • extensionPointId – the unique identifier of extension point
See Also:
Since:org.eclipse.equinox.registry 3.4
/**
	 * Adds the given listener for registry change events related to specified
	 * extension point.
	 * <p>
	 * Once registered, a listener starts receiving notification of changes to
	 * the registry. Registry change notifications are sent asynchronously.
	 * The listener continues to receive notifications until it is removed.
	 * </p><p>
	 * This method has no effect if the listener is already registered.
	 * </p>
	 * @param listener the listener
	 * @param extensionPointId the unique identifier of extension point
	 * @see IExtensionPoint#getUniqueIdentifier()
	 * @since org.eclipse.equinox.registry 3.4
	 */
	public void addListener(IRegistryEventListener listener, String extensionPointId);

	
Removes the given registry change listener from this registry.


This method has no effect if the listener is not registered.



Params:
  • listener – the listener
See Also:
Since:org.eclipse.equinox.registry 3.4
/**
	 * Removes the given registry change listener from this registry.
	 * <p>
	 * This method has no effect if the listener is not registered.
	 * </p>
	 * @param listener the listener
	 * @see #addListener(IRegistryEventListener)
	 * @see #addListener(IRegistryEventListener, String)
	 * @since org.eclipse.equinox.registry 3.4
	 */
	public void removeListener(IRegistryEventListener listener);

	
Call this method to determine if this extension registry supports multiple languages.


See the runtime option "-registryMultiLanguage" for enabling multi-language
support.



Returns:true if multiple languages are supported by this
instance of the extension registry; false otherwise.
Since:org.eclipse.equinox.registry 3.5
/**
	 * Call this method to determine if this extension registry supports multiple languages.
	 * <p>
	 * See the runtime option "-registryMultiLanguage" for enabling multi-language
	 * support.
	 * </p>
	 * @return <code>true</code> if multiple languages are supported by this
	 * instance of the extension registry; <code>false</code> otherwise.
	 * @since org.eclipse.equinox.registry 3.5
	 */
	public boolean isMultiLanguage();
}