    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
    024 * {@link ConfigurationBuilder} to initialize event listeners.
    025 * </p>
    026 * <p>
    027 * This interface allows a convenient initialization of a configuration builder
    028 * with event listeners to be registered at the managed configuration object.
    029 * The {@code configure()} method of {@link BasicConfigurationBuilder} checks
    030 * whether a parameters object passed to it implements this interface. If this
    031 * is the case, all event listeners defined by the object are added to the
    032 * internal list managed by the builder. They are then automatically registered
    033 * at the managed configuration when it is created. When using a corresponding
    034 * implementation the configuration of event listeners can be done in the same
    035 * fluent API style as the other initialization of the configuration builder.
    036 * </p>
    037 *
    038 * @since 2.0
    039 */
    040public interface EventListenerProvider
    041{
    042    /**
    043     * Returns an {@code EventListenerList} object with information about event
    044     * listener registrations. All listeners contained in this object are added
    045     * to the processing {@code ConfigurationBuilder}.
    046     *
    047     * @return the {@code EventListenerList} with event listener registrations
    048     *         (must not be <b>null</b>)
    049     */
    050    EventListenerList getListeners();
    051}