1/*
2 * Copyright (C) 2015 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 */
16package androidx.annotation;
17
18import static java.lang.annotation.ElementType.CONSTRUCTOR;
19import static java.lang.annotation.ElementType.METHOD;
20import static java.lang.annotation.ElementType.PARAMETER;
21import static java.lang.annotation.ElementType.TYPE;
22import static java.lang.annotation.RetentionPolicy.CLASS;
23
24import java.lang.annotation.Documented;
25import java.lang.annotation.Retention;
26import java.lang.annotation.Target;
27
28/**
29 * Denotes that the annotated method or constructor should only be called on the UI thread.
30 * If the annotated element is a class, then all methods in the class should be called
31 * on the UI thread.
32 * <p>
33 * Example:
34 * <pre><code>
35 *  &#64;UiThread
36 *
37 *  public abstract void setText(@NonNull String text) { ... }
38 * </code></pre>
39 *
40 * <p class="note"><b>Note:</b> Ordinarily, an app's UI thread is also the main
41 * thread. However, However, under special circumstances, an app's UI thread
42 * might not be its main thread; for more information, see
43 * <a href="/studio/write/annotations.html#thread-annotations">Thread
44 * annotations</a>.
45 *
46 * @see androidx.annotation.MainThread
47 */
48@Documented
49@Retention(CLASS)
50@Target({METHOD,CONSTRUCTOR,TYPE,PARAMETER})
51public @interface UiThread {
52}
53