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.scxml2; 018 019import org.apache.commons.scxml2.model.EnterableState; 020import org.apache.commons.scxml2.model.Transition; 021import org.apache.commons.scxml2.model.TransitionTarget; 022 023/** 024 * Listener interface for observable entities in the SCXML model. 025 * Observable entities include {@link org.apache.commons.scxml2.model.SCXML} 026 * instances (subscribe to all entry, exit and transition notifications), 027 * {@link org.apache.commons.scxml2.model.State} instances (subscribe to 028 * particular entry and exit notifications) and 029 * {@link org.apache.commons.scxml2.model.Transition} instances (subscribe to 030 * particular transitions). 031 * 032 */ 033public interface SCXMLListener { 034 035 /** 036 * Handle the entry into a EnterableState. 037 * 038 * @param state The EnterableState entered 039 */ 040 void onEntry(EnterableState state); 041 042 /** 043 * Handle the exit out of a EnterableState. 044 * 045 * @param state The EnterableState exited 046 */ 047 void onExit(EnterableState state); 048 049 /** 050 * Handle the transition. 051 * 052 * @param from The source TransitionTarget 053 * @param to The destination TransitionTarget 054 * @param transition The Transition taken 055 * @param event The event name triggering the transition 056 */ 057 void onTransition(TransitionTarget from, TransitionTarget to, 058 Transition transition, String event); 059 060} 061