| /******************************************************************************* |
| * Copyright (c) 2010, 2016 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 |
| * ARTAL Technologies <simon.chemouil@artal.fr> - Allow wildcards in topic names |
| * Lars.Vogel <Lars.Vogel@vogella.com> - Bug 472654 |
| * Alex Blewitt <alex.blewitt@gmail.com> - Bug 476364 |
| *******************************************************************************/ |
| package org.eclipse.e4.core.di.internal.extensions; |
| |
| import java.lang.reflect.ParameterizedType; |
| import java.lang.reflect.Type; |
| import java.util.Collection; |
| import java.util.Dictionary; |
| import java.util.HashMap; |
| import java.util.Hashtable; |
| import java.util.Iterator; |
| import java.util.Map; |
| import java.util.Map.Entry; |
| import javax.annotation.PreDestroy; |
| import org.eclipse.e4.core.di.IInjector; |
| import org.eclipse.e4.core.di.InjectionException; |
| import org.eclipse.e4.core.di.extensions.EventTopic; |
| import org.eclipse.e4.core.di.suppliers.ExtendedObjectSupplier; |
| import org.eclipse.e4.core.di.suppliers.IObjectDescriptor; |
| import org.eclipse.e4.core.di.suppliers.IRequestor; |
| import org.osgi.framework.BundleContext; |
| import org.osgi.framework.FrameworkUtil; |
| import org.osgi.framework.ServiceRegistration; |
| import org.osgi.service.component.annotations.Component; |
| import org.osgi.service.component.annotations.Reference; |
| import org.osgi.service.event.Event; |
| import org.osgi.service.event.EventAdmin; |
| import org.osgi.service.event.EventConstants; |
| import org.osgi.service.event.EventHandler; |
| |
| /** |
| * This class is instantiated and wired by declarative services. |
| */ |
| @Component(service = ExtendedObjectSupplier.class, immediate = true, property = "dependency.injection.annotation=org.eclipse.e4.core.di.extensions.EventTopic") |
| public class EventObjectSupplier extends ExtendedObjectSupplier { |
| |
| // Same as IEventBroker.DATA |
| public static final String DATA = "org.eclipse.e4.data"; //$NON-NLS-1$ |
| |
| private EventAdmin eventAdmin; |
| |
| public EventAdmin getEventAdmin() { |
| return eventAdmin; |
| } |
| |
| @Reference |
| public void setEventAdmin(EventAdmin eventAdmin) { |
| this.eventAdmin = eventAdmin; |
| } |
| |
| protected Map<String, Event> currentEvents = new HashMap<>(); |
| |
| class DIEventHandler implements EventHandler { |
| |
| final private IRequestor requestor; |
| final private String topic; |
| |
| public DIEventHandler(String topic, IRequestor requestor) { |
| this.topic = topic; |
| this.requestor = requestor; |
| } |
| |
| @Override |
| public void handleEvent(Event event) { |
| if (!requestor.isValid()) { |
| unsubscribe(requestor); |
| return; |
| } |
| |
| addCurrentEvent(topic, event); |
| requestor.resolveArguments(false); |
| removeCurrentEvent(topic); |
| |
| requestor.execute(); |
| } |
| } |
| |
| // A combo of { IRequestor + topic } used in Map lookups |
| static private class Subscriber { |
| private IRequestor requestor; |
| private String topic; |
| |
| public Subscriber(IRequestor requestor, String topic) { |
| super(); |
| this.requestor = requestor; |
| this.topic = topic; |
| } |
| |
| @Override |
| public int hashCode() { |
| final int prime = 31; |
| int result = 1; |
| result = prime * result + ((requestor == null) ? 0 : requestor.hashCode()); |
| result = prime * result + ((topic == null) ? 0 : topic.hashCode()); |
| return result; |
| } |
| |
| public IRequestor getRequestor() { |
| return requestor; |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) |
| return true; |
| if (obj == null) |
| return false; |
| if (getClass() != obj.getClass()) |
| return false; |
| Subscriber other = (Subscriber) obj; |
| if (requestor == null) { |
| if (other.requestor != null) |
| return false; |
| } else if (!requestor.equals(other.requestor)) |
| return false; |
| if (topic == null) { |
| if (other.topic != null) |
| return false; |
| } else if (!topic.equals(other.topic)) |
| return false; |
| return true; |
| } |
| |
| } |
| |
| private Map<Subscriber, ServiceRegistration<EventHandler>> registrations = new HashMap<>(); |
| |
| protected void addCurrentEvent(String topic, Event event) { |
| synchronized (currentEvents) { |
| currentEvents.put(topic, event); |
| } |
| } |
| |
| protected void removeCurrentEvent(String topic) { |
| synchronized (currentEvents) { |
| currentEvents.remove(topic); |
| } |
| } |
| |
| @Override |
| public Object get(IObjectDescriptor descriptor, IRequestor requestor, boolean track, boolean group) { |
| if (descriptor == null) |
| return null; |
| String topic = getTopic(descriptor); |
| if (topic == null || eventAdmin == null || topic.length() == 0) |
| return IInjector.NOT_A_VALUE; |
| |
| if (track) |
| subscribe(topic, requestor); |
| else |
| unsubscribe(requestor); |
| |
| if (!currentEvents.containsKey(topic)) |
| return IInjector.NOT_A_VALUE; |
| |
| // convert to fit destination |
| Class<?> descriptorsClass = getDesiredClass(descriptor.getDesiredType()); |
| if (descriptorsClass.equals(Event.class)) |
| return currentEvents.get(topic); |
| return currentEvents.get(topic).getProperty(DATA); |
| } |
| |
| private void subscribe(String topic, IRequestor requestor) { |
| Subscriber subscriber = new Subscriber(requestor, topic); |
| synchronized (registrations) { |
| if (registrations.containsKey(subscriber)) |
| return; |
| } |
| BundleContext bundleContext = FrameworkUtil.getBundle(EventObjectSupplier.class).getBundleContext(); |
| if (bundleContext == null) |
| throw new InjectionException( |
| "Unable to subscribe to events: org.eclipse.e4.core.di.extensions bundle is not activated"); //$NON-NLS-1$ |
| |
| String[] topics = new String[] { topic }; |
| Dictionary<String, Object> d = new Hashtable<>(); |
| d.put(EventConstants.EVENT_TOPIC, topics); |
| EventHandler wrappedHandler = makeHandler(topic, requestor); |
| ServiceRegistration<EventHandler> registration = bundleContext.registerService(EventHandler.class, |
| wrappedHandler, d); |
| // due to the way requestors are constructed this limited synch should |
| // be OK |
| synchronized (registrations) { |
| registrations.put(subscriber, registration); |
| } |
| } |
| |
| protected EventHandler makeHandler(String topic, IRequestor requestor) { |
| return new DIEventHandler(topic, requestor); |
| } |
| |
| protected String getTopic(IObjectDescriptor descriptor) { |
| if (descriptor == null) |
| return null; |
| EventTopic qualifier = descriptor.getQualifier(EventTopic.class); |
| return qualifier.value(); |
| } |
| |
| protected void unsubscribe(IRequestor requestor) { |
| if (requestor == null) |
| return; |
| synchronized (registrations) { |
| Iterator<Entry<Subscriber, ServiceRegistration<EventHandler>>> i = registrations.entrySet().iterator(); |
| while (i.hasNext()) { |
| Entry<Subscriber, ServiceRegistration<EventHandler>> entry = i.next(); |
| Subscriber key = entry.getKey(); |
| if (!requestor.equals(key.getRequestor())) |
| continue; |
| ServiceRegistration<EventHandler> registration = entry.getValue(); |
| registration.unregister(); |
| i.remove(); |
| } |
| } |
| } |
| |
| @SuppressWarnings("rawtypes") |
| @PreDestroy |
| public void dispose() { |
| ServiceRegistration[] array; |
| synchronized (registrations) { |
| Collection<ServiceRegistration<EventHandler>> values = registrations.values(); |
| array = values.toArray(new ServiceRegistration[values.size()]); |
| registrations.clear(); |
| } |
| for (ServiceRegistration element : array) { |
| element.unregister(); |
| } |
| } |
| |
| private Class<?> getDesiredClass(Type desiredType) { |
| if (desiredType instanceof Class<?>) |
| return (Class<?>) desiredType; |
| if (desiredType instanceof ParameterizedType) { |
| Type rawType = ((ParameterizedType) desiredType).getRawType(); |
| if (rawType instanceof Class<?>) |
| return (Class<?>) rawType; |
| } |
| return null; |
| } |
| |
| } |