| /* |
| * Copyright (C) 2019 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.permissioncontroller.permission.data |
| |
| import android.os.Binder |
| import com.android.permissioncontroller.permission.utils.IPC |
| import kotlinx.coroutines.Dispatchers.Main |
| import kotlinx.coroutines.GlobalScope |
| import kotlinx.coroutines.Job |
| import kotlinx.coroutines.launch |
| |
| /** |
| * A LiveData which loads its data in a background AsyncTask. It will cancel current tasks, if new |
| * requests come during execution |
| */ |
| abstract class SmartAsyncMediatorLiveData<T> : SmartUpdateMediatorLiveData<T>() { |
| |
| private var currentJob: Job? = null |
| @Volatile |
| private var jobQueued = false |
| @Volatile |
| private var jobRunning = false |
| |
| /** |
| * The main function which will load data. It should periodically check isCancelled to see if |
| * it should stop working. If data is loaded, it should call "postValue". |
| */ |
| abstract suspend fun loadDataAndPostValue(job: Job) |
| |
| override fun onUpdate() { |
| updateAsync() |
| } |
| |
| open fun updateAsync() { |
| if (jobRunning) { |
| jobQueued = true |
| return |
| } else { |
| jobRunning = true |
| } |
| |
| GlobalScope.launch(IPC) { |
| currentJob = coroutineContext[Job] |
| loadDataAndPostValue(currentJob!!) |
| // TODO ntmyren: generalize this command to the IPC dispatcher |
| Binder.flushPendingCommands() |
| jobRunning = false |
| if (jobQueued) { |
| jobQueued = false |
| GlobalScope.launch(Main.immediate) { |
| updateAsync() |
| } |
| } |
| } |
| } |
| |
| override fun onInactive() { |
| cancelJobIfRunning() |
| jobQueued = false |
| super.onInactive() |
| } |
| |
| private fun cancelJobIfRunning() { |
| currentJob?.let { job -> |
| if (job.isActive) { |
| job.cancel() |
| } |
| } |
| } |
| } |