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 */ 017 package org.apache.commons.scxml; 018 019 import org.apache.commons.scxml.model.Transition; 020 import org.apache.commons.scxml.model.TransitionTarget; 021 022 /** 023 * Listener interface for observable entities in the SCXML model. 024 * Observable entities include {@link org.apache.commons.scxml.model.SCXML} 025 * instances (subscribe to all entry, exit and transition notifications), 026 * {@link org.apache.commons.scxml.model.State} instances (subscribe to 027 * particular entry and exit notifications) and 028 * {@link org.apache.commons.scxml.model.Transition} instances (subscribe to 029 * particular transitions). 030 * 031 */ 032 public interface SCXMLListener { 033 034 /** 035 * Handle the entry into a TransitionTarget. 036 * 037 * @param state The TransitionTarget entered 038 */ 039 void onEntry(TransitionTarget state); 040 041 /** 042 * Handle the exit out of a TransitionTarget. 043 * 044 * @param state The TransitionTarget exited 045 */ 046 void onExit(TransitionTarget state); 047 048 /** 049 * Handle the transition. 050 * 051 * @param from The source TransitionTarget 052 * @param to The destination TransitionTarget 053 * @param transition The Transition taken 054 */ 055 void onTransition(TransitionTarget from, TransitionTarget to, 056 Transition transition); 057 058 } 059