    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.io;
    018
    019/**
    020 * <p>
    021 * A listener interface for receiving notifications about updates of a {@code FileHandler}.
    022 * </p>
    023 * <p>
    024 * Objects implementing this interface are notified when properties of a {@code FileHandler} change or when a load or
    025 * save operation is performed. This can be useful for various use cases, e.g. when monitoring file-based
    026 * configurations.
    027 * </p>
    028 *
    029 * @since 2.0
    030 */
    031public interface FileHandlerListener {
    032    /**
    033     * Notification that the associated file is about to be loaded. This method is called immediately before the load
    034     * operation.
    035     *
    036     * @param handler the file handler
    037     */
    038    void loading(FileHandler handler);
    039
    040    /**
    041     * Notification that the associated file has been loaded. This method is called directly after the load operation.
    042     *
    043     * @param handler the file handler
    044     */
    045    void loaded(FileHandler handler);
    046
    047    /**
    048     * Notification that the associated file is about to be saved. This method is called immediately before the save
    049     * operation.
    050     *
    051     * @param handler the file handler
    052     */
    053    void saving(FileHandler handler);
    054
    055    /**
    056     * Notification that the associated file has been saved. This method is called directly after the save operation.
    057     *
    058     * @param handler the file handler
    059     */
    060    void saved(FileHandler handler);
    061
    062    /**
    063     * Notification that a property of the monitored {@code FileHandler} has changed.
    064     *
    065     * @param handler the file handler
    066     */
    067    void locationChanged(FileHandler handler);
    068}