/****************************************************************************
 * Copyright 2007 Eric M. Burke                                             *
 *                                                                          *
 * 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 com.stuffthathappens.classbus;

/**
 * To receive events, you must implement this interface. An "event" is actually any
 * Java object. Subscribers are only notified if both the channel and event
 * {@link com.stuffthathappens.classbus.Matcher} objects pass.
 *
 * @author Eric M. Burke
 * @see EventService#subscribe(Matcher, Matcher, EventSubscriber)
 * @see MatcherMaker
 */
public interface EventSubscriber<T> {

    /**
     * Invoked if the event passes the channel and event matchers.
     *
     * @param event the object being delivered via the "bus".
     */
    void onEvent(T event);
}