1 /* 2 * Copyright (C) 2024 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.fuelgauge.batteryusage 18 19 import android.os.AsyncTask 20 import androidx.annotation.CallSuper 21 import androidx.annotation.OpenForTesting 22 import androidx.lifecycle.DefaultLifecycleObserver 23 import androidx.lifecycle.Lifecycle 24 import androidx.lifecycle.LifecycleOwner 25 import com.android.settingslib.datastore.HandlerExecutor.Companion.main as mainExecutor 26 27 /** 28 * Lifecycle aware [AsyncTask] to cancel task automatically when [lifecycle] is stopped. 29 * 30 * Must call [start] instead of [execute] to run the task. 31 */ 32 abstract class LifecycleAwareAsyncTask<Result>(private val lifecycle: Lifecycle?) : 33 AsyncTask<Void, Void, Result>(), DefaultLifecycleObserver { 34 35 @CallSuper onPostExecutenull36 override fun onPostExecute(result: Result) { 37 lifecycle?.removeObserver(this) 38 } 39 onStopnull40 override fun onStop(owner: LifecycleOwner) { 41 cancel(false) 42 lifecycle?.removeObserver(this) 43 } 44 45 /** 46 * Starts the task, which invokes [execute] (cannot override [execute] as it is final). 47 * 48 * This method is expected to be invoked from main thread but current usage might call from 49 * background thread. 50 */ startnull51 fun start() { 52 execute() // expects main thread 53 val lifecycle = lifecycle ?: return 54 mainExecutor.execute { maybeAddObserver(lifecycle) } 55 } 56 57 @OpenForTesting maybeAddObservernull58 open fun maybeAddObserver(lifecycle: Lifecycle) { 59 // Status is updated to FINISHED if onPoseExecute happened before. And task is cancelled 60 // if lifecycle is stopped. 61 if (status == Status.RUNNING && !isCancelled) { 62 lifecycle.addObserver(this) // requires main thread 63 } 64 } 65 } 66