1 /*
2  * Copyright (C) 2020 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 com.android.settings;
18 
19 import android.os.AsyncTask;
20 
21 import androidx.annotation.Nullable;
22 
23 import com.android.settingslib.utils.ThreadUtils;
24 
25 import java.util.concurrent.Future;
26 
27 /** A {@link SidecarFragment} which uses an {@link AsyncTask} to perform background work. */
28 public abstract class AsyncTaskSidecar<Param, Result> extends SidecarFragment {
29 
30     private Future<Result> mAsyncTask;
31 
32     @Override
onDestroy()33     public void onDestroy() {
34         if (mAsyncTask != null) {
35             mAsyncTask.cancel(true /* mayInterruptIfRunning */);
36         }
37 
38         super.onDestroy();
39     }
40 
41     /**
42      * Executes the background task.
43      *
44      * @param param parameters passed in from {@link #run}
45      */
doInBackground(@ullable Param param)46     protected abstract Result doInBackground(@Nullable Param param);
47 
48     /** Handles the background task's result. */
onPostExecute(Result result)49     protected void onPostExecute(Result result) {}
50 
51     /** Runs the sidecar and sets the state to RUNNING. */
run(@ullable final Param param)52     public void run(@Nullable final Param param) {
53         setState(State.RUNNING, Substate.UNUSED);
54 
55         if (mAsyncTask != null) {
56             mAsyncTask.cancel(true /* mayInterruptIfRunning */);
57         }
58 
59         mAsyncTask =
60                 ThreadUtils.postOnBackgroundThread(
61                         () -> {
62                             Result result = doInBackground(param);
63                             ThreadUtils.postOnMainThread(() -> onPostExecute(result));
64                         });
65     }
66 }
67