1 /*
2  * Copyright 2021 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 androidx.compose.ui.inspection.util
18 
19 import android.os.Handler
20 import android.os.Looper
21 import java.util.concurrent.CompletableFuture
22 import java.util.concurrent.Future
23 
24 object ThreadUtils {
assertOnMainThreadnull25     fun assertOnMainThread() {
26         if (!Looper.getMainLooper().isCurrentThread) {
27             error("This work is required on the main thread")
28         }
29     }
30 
assertOffMainThreadnull31     fun assertOffMainThread() {
32         if (Looper.getMainLooper().isCurrentThread) {
33             error("This work is required off the main thread")
34         }
35     }
36 
37     /**
38      * Run some logic on the main thread, returning a future that will contain any data computed by
39      * and returned from the block.
40      *
41      * If this method is called from the main thread, it will run immediately.
42      */
runOnMainThreadnull43     fun <T> runOnMainThread(block: () -> T): Future<T> {
44         return if (!Looper.getMainLooper().isCurrentThread) {
45             val future = CompletableFuture<T>()
46             Handler.createAsync(Looper.getMainLooper()).post { future.complete(block()) }
47             future
48         } else {
49             CompletableFuture.completedFuture(block())
50         }
51     }
52 }
53