| /* |
| * Copyright (c) OSGi Alliance (2007, 2010). All Rights Reserved. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.osgi.util.tracker; |
| |
| import org.osgi.framework.Bundle; |
| import org.osgi.framework.BundleEvent; |
| |
| /** |
| * The {@code BundleTrackerCustomizer} interface allows a |
| * {@code BundleTracker} to customize the {@code Bundle}s that are |
| * tracked. A {@code BundleTrackerCustomizer} is called when a bundle is |
| * being added to a {@code BundleTracker}. The |
| * {@code BundleTrackerCustomizer} can then return an object for the |
| * tracked bundle. A {@code BundleTrackerCustomizer} is also called when a |
| * tracked bundle is modified or has been removed from a |
| * {@code BundleTracker}. |
| * |
| * <p> |
| * The methods in this interface may be called as the result of a |
| * {@code BundleEvent} being received by a {@code BundleTracker}. |
| * Since {@code BundleEvent}s are received synchronously by the |
| * {@code BundleTracker}, it is highly recommended that implementations of |
| * these methods do not alter bundle states while being synchronized on any |
| * object. |
| * |
| * <p> |
| * The {@code BundleTracker} class is thread-safe. It does not call a |
| * {@code BundleTrackerCustomizer} while holding any locks. |
| * {@code BundleTrackerCustomizer} implementations must also be |
| * thread-safe. |
| * |
| * @param <T> The type of the tracked object. |
| * @ThreadSafe |
| * @version $Id: 0e80f2555530b217faef57726a5938f0087a45c5 $ |
| * @since 1.4 |
| */ |
| public interface BundleTrackerCustomizer<T> { |
| /** |
| * A bundle is being added to the {@code BundleTracker}. |
| * |
| * <p> |
| * This method is called before a bundle which matched the search parameters |
| * of the {@code BundleTracker} is added to the |
| * {@code BundleTracker}. This method should return the object to be |
| * tracked for the specified {@code Bundle}. The returned object is |
| * stored in the {@code BundleTracker} and is available from the |
| * {@link BundleTracker#getObject(Bundle) getObject} method. |
| * |
| * @param bundle The {@code Bundle} being added to the |
| * {@code BundleTracker}. |
| * @param event The bundle event which caused this customizer method to be |
| * called or {@code null} if there is no bundle event associated |
| * with the call to this method. |
| * @return The object to be tracked for the specified {@code Bundle} |
| * object or {@code null} if the specified {@code Bundle} |
| * object should not be tracked. |
| */ |
| public T addingBundle(Bundle bundle, BundleEvent event); |
| |
| /** |
| * A bundle tracked by the {@code BundleTracker} has been modified. |
| * |
| * <p> |
| * This method is called when a bundle being tracked by the |
| * {@code BundleTracker} has had its state modified. |
| * |
| * @param bundle The {@code Bundle} whose state has been modified. |
| * @param event The bundle event which caused this customizer method to be |
| * called or {@code null} if there is no bundle event associated |
| * with the call to this method. |
| * @param object The tracked object for the specified bundle. |
| */ |
| public void modifiedBundle(Bundle bundle, BundleEvent event, |
| T object); |
| |
| /** |
| * A bundle tracked by the {@code BundleTracker} has been removed. |
| * |
| * <p> |
| * This method is called after a bundle is no longer being tracked by the |
| * {@code BundleTracker}. |
| * |
| * @param bundle The {@code Bundle} that has been removed. |
| * @param event The bundle event which caused this customizer method to be |
| * called or {@code null} if there is no bundle event associated |
| * with the call to this method. |
| * @param object The tracked object for the specified bundle. |
| */ |
| public void removedBundle(Bundle bundle, BundleEvent event, |
| T object); |
| } |