| /******************************************************************************* |
| * Copyright (c) 2004, 2008 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.core.runtime.dynamichelpers; |
| |
| import org.eclipse.core.internal.runtime.ReferenceHashSet; |
| import org.eclipse.core.runtime.IExtension; |
| |
| /** |
| * An extension tracker keeps associations between extensions and their derived objects on an extension basis. |
| * All extensions being added in a tracker will automatically be removed when the extension is uninstalled from the registry. |
| * Users interested in extension removal can register a handler that will let them know when an object is being removed. |
| * <p> |
| * This interface can be used without OSGi running. |
| * </p><p> |
| * This interface is not intended to be implemented by clients. |
| * </p> |
| * @since 3.1 |
| * @noimplement This interface is not intended to be implemented by clients. |
| */ |
| public interface IExtensionTracker { |
| |
| /** |
| * Constant for strong (normal) reference holding. |
| * |
| * Value <code>1</code>. |
| */ |
| public static final int REF_STRONG = ReferenceHashSet.HARD; |
| |
| /** |
| * Constant for soft reference holding. |
| * |
| * Value <code>2</code>. |
| */ |
| public static final int REF_SOFT = ReferenceHashSet.SOFT; |
| |
| /** |
| * Constant for weak reference holding. |
| * |
| * Value <code>3</code>. |
| */ |
| public static final int REF_WEAK = ReferenceHashSet.WEAK; |
| |
| /** |
| * Register an extension change handler with this tracker using the given filter. |
| * |
| * @param handler the handler to be registered |
| * @param filter the filter to use to choose interesting changes |
| */ |
| public void registerHandler(IExtensionChangeHandler handler, IFilter filter); |
| |
| /** |
| * Unregister the given extension change handler previously registered with this tracker. |
| * |
| * @param handler the handler to be unregistered |
| */ |
| public void unregisterHandler(IExtensionChangeHandler handler); |
| |
| /** |
| * Create an association between the given extension and the given object. |
| * The referenceType indicates how strongly the object is being kept in memory. |
| * There is 3 possible values: {@link #REF_STRONG}, {@link #REF_SOFT}, {@link #REF_WEAK}. |
| * |
| * @param extension the extension |
| * @param object the object to associate with the extension |
| * @param referenceType one of REF_STRONG, REF_SOFT, REF_WEAK |
| * @see #REF_STRONG |
| * @see #REF_SOFT |
| * @see #REF_WEAK |
| */ |
| public void registerObject(IExtension extension, Object object, int referenceType); |
| |
| /** |
| * Remove an association between the given extension and the given object. |
| * |
| * @param extension the extension under which the object has been registered |
| * @param object the object to unregister |
| */ |
| public void unregisterObject(IExtension extension, Object object); |
| |
| /** |
| * Remove all the objects associated with the given extension. Return |
| * the removed objects. |
| * |
| * @param extension the extension for which the objects are removed |
| * @return the objects that were associated with the extension |
| */ |
| public Object[] unregisterObject(IExtension extension); |
| |
| /** |
| * Return all the objects that have been associated with the given extension. |
| * All objects registered strongly will be return unless they have been unregistered. |
| * The objects registered softly or weakly may not be returned if they have been garbage collected. |
| * Return an empty array if no associations exist. |
| * |
| * @param extension the extension for which the object must be returned |
| * @return the array of associated objects |
| */ |
| public Object[] getObjects(IExtension extension); |
| |
| /** |
| * Close the tracker. All registered objects are freed and all handlers are being automatically removed. |
| */ |
| public void close(); |
| } |