    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *     http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.configuration2.builder;
    018
    019import org.apache.commons.configuration2.event.EventListenerList;
    020
    021/**
    022 * <p>
    023 * Definition of an interface that is evaluated by a {@link ConfigurationBuilder} to initialize event listeners.
    024 * </p>
    025 * <p>
    026 * This interface allows a convenient initialization of a configuration builder with event listeners to be registered at
    027 * the managed configuration object. The {@code configure()} method of {@link BasicConfigurationBuilder} checks whether
    028 * a parameters object passed to it implements this interface. If this is the case, all event listeners defined by the
    029 * object are added to the internal list managed by the builder. They are then automatically registered at the managed
    030 * configuration when it is created. When using a corresponding implementation the configuration of event listeners can
    031 * be done in the same fluent API style as the other initialization of the configuration builder.
    032 * </p>
    033 *
    034 * @since 2.0
    035 */
    036public interface EventListenerProvider {
    037    /**
    038     * Returns an {@code EventListenerList} object with information about event listener registrations. All listeners
    039     * contained in this object are added to the processing {@code ConfigurationBuilder}.
    040     *
    041     * @return the {@code EventListenerList} with event listener registrations (must not be <b>null</b>)
    042     */
    043    EventListenerList getListeners();
    044}