1 /*
2  * Copyright (C) 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License
15  */
16 
17 package android.compat.annotation;
18 
19 import static java.lang.annotation.ElementType.FIELD;
20 import static java.lang.annotation.ElementType.PARAMETER;
21 import static java.lang.annotation.RetentionPolicy.SOURCE;
22 
23 import java.lang.annotation.Retention;
24 import java.lang.annotation.Target;
25 
26 /**
27  * Indicates that a field is a compatibility change ID.
28  *
29  * <p>A compatibility change is a change to the Android platform that may impact app behavior,
30  * relative to previous releases of Android. A change ID is a unique {@code long} identifying one
31  * such change. Compatibility change IDs should be defined as a {@code static final long}:
32  *
33  * <pre>{@code
34  *     @ChangeId
35  *     public static final long MY_CHANGE_ID = 123456789l;
36  * }</pre>
37  *
38  * <p>The value of the constant is the ID of an issue in <a href="https://issuetracker.google.com/">
39  * buganizer</a>.
40  *
41  * @hide
42  */
43 @Retention(SOURCE)
44 @Target({FIELD, PARAMETER})
45 public @interface ChangeId {
46 }
47