Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
ChangeObserver |
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| 1.0;1 |
1 | // Copyright 2004, 2005 The Apache Software Foundation | |
2 | // | |
3 | // Licensed under the Apache License, Version 2.0 (the "License"); | |
4 | // you may not use this file except in compliance with the License. | |
5 | // You may obtain a copy of the License at | |
6 | // | |
7 | // http://www.apache.org/licenses/LICENSE-2.0 | |
8 | // | |
9 | // Unless required by applicable law or agreed to in writing, software | |
10 | // distributed under the License is distributed on an "AS IS" BASIS, | |
11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
12 | // See the License for the specific language governing permissions and | |
13 | // limitations under the License. | |
14 | ||
15 | package org.apache.tapestry.event; | |
16 | ||
17 | /** | |
18 | * May observe changes in an object's properties. This is a "weak" variation | |
19 | * on JavaBean's style bound properties. It is used when there will be at most | |
20 | * a single listener on property changes, and that the listener is not interested | |
21 | * in the old value. | |
22 | * | |
23 | * @author Howard Lewis Ship | |
24 | * | |
25 | **/ | |
26 | ||
27 | public interface ChangeObserver | |
28 | { | |
29 | /** | |
30 | * Sent when the observed object changes a property. The event identifies | |
31 | * the object, the property and the new value. | |
32 | * | |
33 | **/ | |
34 | ||
35 | void observeChange(ObservedChangeEvent event); | |
36 | ||
37 | /** | |
38 | * Checks if the current state changes have already been committed. | |
39 | * | |
40 | * @return True if state changes are locked, false otherwise. | |
41 | */ | |
42 | boolean isLocked(); | |
43 | } |