/*
 * Copyright (c) OSGi Alliance (2010, 2013). 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.framework.hooks.bundle;

import java.util.Collection;
import org.osgi.annotation.versioning.ConsumerType;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleEvent;

OSGi Framework Bundle Event Hook Service.

Bundles registering this service will be called during framework lifecycle
(install, start, stop, update, and uninstall bundle) operations.
Author:
$Id: 0b986db904e41d5a5bfb5d28fc849ee967decf0d $
@ThreadSafe
/**
 * OSGi Framework Bundle Event Hook Service.
 * 
 * <p>
 * Bundles registering this service will be called during framework lifecycle
 * (install, start, stop, update, and uninstall bundle) operations.
 * 
 * @ThreadSafe
 * @author $Id: 0b986db904e41d5a5bfb5d28fc849ee967decf0d $
 */
@ConsumerType
public interface EventHook {

	
Bundle event hook method. This method is called prior to bundle event
delivery when a bundle is installed, resolved, started, stopped,
unresolved, or uninstalled. This method can filter the bundles which
receive the event.

This method must be called by the framework one and only one time for
each bundle event generated, this included bundle events which are
generated when there are no bundle listeners registered. This method must
be called on the same thread that is performing the action which
generated the specified event. The specified collection includes bundle
contexts with synchronous and asynchronous bundle listeners registered
with them.
Params:
event – The bundle event to be delivered
contexts – A collection of Bundle Contexts for bundles which have listeners to which the specified event will be delivered. The implementation of this method may remove bundle contexts from the collection to prevent the event from being delivered to the associated bundles. The collection supports all the optional Collection operations except add and addAll. Attempting to add to the collection will result in an UnsupportedOperationException. The collection is not synchronized./**
	 * Bundle event hook method. This method is called prior to bundle event
	 * delivery when a bundle is installed, resolved, started, stopped,
	 * unresolved, or uninstalled. This method can filter the bundles which
	 * receive the event.
	 * <p>
	 * This method must be called by the framework one and only one time for
	 * each bundle event generated, this included bundle events which are
	 * generated when there are no bundle listeners registered. This method must
	 * be called on the same thread that is performing the action which
	 * generated the specified event. The specified collection includes bundle
	 * contexts with synchronous and asynchronous bundle listeners registered
	 * with them.
	 * 
	 * @param event The bundle event to be delivered
	 * @param contexts A collection of Bundle Contexts for bundles which have
	 *        listeners to which the specified event will be delivered. The
	 *        implementation of this method may remove bundle contexts from the
	 *        collection to prevent the event from being delivered to the
	 *        associated bundles. The collection supports all the optional
	 *        {@code Collection} operations except {@code add} and
	 *        {@code addAll}. Attempting to add to the collection will result in
	 *        an {@code UnsupportedOperationException}. The collection is not
	 *        synchronized.
	 */
	void event(BundleEvent event, Collection<BundleContext> contexts);
}