/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.karaf.eik.workbench.internal;
import org.apache.karaf.eik.workbench.KarafWorkbenchActivator;
import org.apache.karaf.eik.workbench.WorkbenchServiceListener;
import org.apache.karaf.eik.workbench.WorkbenchServiceManager;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.eclipse.core.runtime.ISafeRunnable;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.core.runtime.SafeRunner;
import org.eclipse.core.runtime.Status;
public abstract class AbstractWorkbenchServiceManager<T> implements WorkbenchServiceManager<T> {
protected final List<T> serviceDescriptors;
protected final ListenerList listeners;
protected static enum EventType {
ADDED,
REMOVED;
}
private final class Notifier implements ISafeRunnable {
private EventType event;
private WorkbenchServiceListener<T> listener;
private T service;
public Notifier() {
// Intentionally left blank
}
@Override
public void handleException(final Throwable exception) {
final IStatus status =
new Status(
IStatus.ERROR,
KarafWorkbenchActivator.PLUGIN_ID,
120,
"An exception occurred during change notification.", exception); //$NON-NLS-1$
KarafWorkbenchActivator.getDefault().getLog().log(status);
}
@Override
public void run() throws Exception {
switch (event) {
case ADDED:
listener.serviceAdded(service);
break;
case REMOVED:
listener.serviceRemoved(service);
break;
}
}
/**
* Notifies the listeners of the add/remove
*
* @param serviceUrls the {@link T}s that changed
* @param event the type of change
*/
@SuppressWarnings("unchecked")
public void notify(final List<T> serviceUrls, final EventType e) {
this.event = e;
final Object[] copiedListeners = listeners.getListeners();
for (int i= 0; i < copiedListeners.length; i++) {
listener = (WorkbenchServiceListener<T>) copiedListeners[i];
for(final T url : serviceUrls) {
service = url;
SafeRunner.run(this);
}
}
listener = null;
service = null;
}
}
protected AbstractWorkbenchServiceManager() {
serviceDescriptors = Collections.synchronizedList(new ArrayList<T>());
listeners = new ListenerList();
}
@Override
public void add(final T service) {
add(Collections.singletonList(service));
}
@Override
public void addListener(final WorkbenchServiceListener<T> listener) {
listeners.add(listener);
}
@Override
public void add(final List<T> services) {
serviceDescriptors.addAll(services);
getNotifier().notify(services, EventType.ADDED);
}
@Override
public List<T> getServices() {
return Collections.unmodifiableList(serviceDescriptors);
}
@Override
public boolean isRegistered(final T service) {
return serviceDescriptors.contains(service);
}
@Override
public void remove(final T service) {
remove(Collections.singletonList(service));
}
@Override
public void removeListener(final WorkbenchServiceListener<T> listener) {
listeners.remove(listener);
}
@Override
public void remove(final List<T> services) {
serviceDescriptors.removeAll(services);
getNotifier().notify(services, EventType.REMOVED);
}
protected Notifier getNotifier() {
return new Notifier();
}
}