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 package com.android.launcher3.util; 17 18 import android.database.ContentObserver; 19 import android.net.Uri; 20 import android.os.Handler; 21 import android.os.Looper; 22 23 import androidx.annotation.WorkerThread; 24 25 import java.util.function.Consumer; 26 27 /** 28 * Utility class to define an object which does most of it's processing on a 29 * dedicated background thread. 30 */ 31 public abstract class BgObjectWithLooper { 32 33 /** 34 * Start initialization of the object 35 */ initializeInBackground(String threadName)36 public final void initializeInBackground(String threadName) { 37 new Thread(this::runOnThread, threadName).start(); 38 } 39 runOnThread()40 private void runOnThread() { 41 Looper.prepare(); 42 onInitialized(Looper.myLooper()); 43 Looper.loop(); 44 } 45 46 /** 47 * Called on the background thread to handle initialization 48 */ 49 @WorkerThread onInitialized(Looper looper)50 protected abstract void onInitialized(Looper looper); 51 52 /** 53 * Helper method to create a content provider 54 */ newContentObserver(Handler handler, Consumer<Uri> command)55 protected static ContentObserver newContentObserver(Handler handler, Consumer<Uri> command) { 56 return new ContentObserver(handler) { 57 @Override 58 public void onChange(boolean selfChange, Uri uri) { 59 command.accept(uri); 60 } 61 }; 62 } 63 } 64