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.wicket;
018
019/**
020 * Listens to {@link Component#detach()} calls.
021 * 
022 * Detach listeners are called as the last step in the process of detaching a component; this means
023 * the component is in a fully detached state when the listener is invoked.
024 * 
025 * @author igor.vaynberg
026 * 
027 * @see org.apache.wicket.settings.FrameworkSettings#setDetachListener(IDetachListener)
028 */
029public interface IDetachListener
030{
031        /**
032         * Called when component is being detached via a call to {@link Component#detach()}.
033         * 
034         * NOTICE: The component is in a fully detached state when this method is invoked; It is the
035         * listener's responsibility to maintain the detached state after this method is finished -
036         * which means if the listener causes any part of the component (eg model) to become reattached
037         * it is the listener's responsibility to detach it before this method exits.
038         * 
039         * @param component
040         *            component being detached
041         */
042        default void onDetach(Component component)
043        {}
044
045        /**
046         * Called when the application is being destroyed. Useful for cleaning up listener caches, etc.
047         */
048        default void onDestroyListener()
049        {}
050}