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.model;
018
019/**
020 * Interface for elements of the SCXML object model whose progress
021 * can be observed using the {@link org.apache.commons.scxml2.NotificationRegistry}. These include
022 * individual {@link TransitionTarget}s, {@link Transition}s or the entire state
023 * machine {@link SCXML}.
024 *
025 * <p>Note: it is assumed there will be no more than Integer.MAX_VALUE of such elements in a single SCXML document</p>
026 */
027public interface Observable {
028
029    /**
030     * @return Returns the id for this Observable which is unique within the SCXML state machine
031     */
032    Integer getObservableId();
033}
034