1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.scxml;
18
19 import org.apache.commons.scxml.model.Transition;
20 import org.apache.commons.scxml.model.TransitionTarget;
21
22 /**
23 * Listener interface for observable entities in the SCXML model.
24 * Observable entities include {@link org.apache.commons.scxml.model.SCXML}
25 * instances (subscribe to all entry, exit and transition notifications),
26 * {@link org.apache.commons.scxml.model.State} instances (subscribe to
27 * particular entry and exit notifications) and
28 * {@link org.apache.commons.scxml.model.Transition} instances (subscribe to
29 * particular transitions).
30 *
31 */
32 public interface SCXMLListener {
33
34 /**
35 * Handle the entry into a TransitionTarget.
36 *
37 * @param state The TransitionTarget entered
38 */
39 void onEntry(TransitionTarget state);
40
41 /**
42 * Handle the exit out of a TransitionTarget.
43 *
44 * @param state The TransitionTarget exited
45 */
46 void onExit(TransitionTarget state);
47
48 /**
49 * Handle the transition.
50 *
51 * @param from The source TransitionTarget
52 * @param to The destination TransitionTarget
53 * @param transition The Transition taken
54 */
55 void onTransition(TransitionTarget from, TransitionTarget to,
56 Transition transition);
57
58 }
59