interactivespaces.event.EventListenerCollection.java Source code

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Here is the source code for interactivespaces.event.EventListenerCollection.java

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/*
 * Copyright (C) 2012 Google Inc.
 *
 * 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 interactivespaces.event;

import com.google.common.collect.LinkedHashMultimap;
import com.google.common.collect.Multimaps;
import com.google.common.collect.SetMultimap;

/**
 * A collection of {@link EventListener} instances.
 *
 * <p>
 * Provides useful methods for wotking with the collection.
 *
 * @author Keith M. Hughes
 */
public class EventListenerCollection implements EventSubscriber {

    /**
     * A map of listeners keyed by the event type.
     */
    private SetMultimap<String, EventListener> listeners;

    public EventListenerCollection() {
        listeners = LinkedHashMultimap.create();
        listeners = Multimaps.synchronizedSetMultimap(listeners);
    }

    @Override
    public void addEventListener(String type, EventListener listener) {
        listeners.put(type, listener);
    }

    @Override
    public void removeEventListener(String type, EventListener listener) {
        listeners.remove(type, listener);
    }

    /**
     * Send the event to all listeners in the collection for the event type.
     *
     * @param event
     *          the event to broadcast
     */
    public void broadcastEvent(Event event) {
        for (EventListener listener : listeners.get(event.getType())) {
            listener.onEvent(event);
        }
    }
}