1 /* 2 * Copyright (C) 2013 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.systemui.settings; 18 19 import android.app.ActivityManager; 20 import android.content.BroadcastReceiver; 21 import android.content.Context; 22 import android.content.Intent; 23 import android.content.IntentFilter; 24 25 import com.android.internal.annotations.VisibleForTesting; 26 27 import java.util.ArrayList; 28 import java.util.List; 29 import java.util.function.Consumer; 30 31 public abstract class CurrentUserTracker { 32 private final UserReceiver mUserReceiver; 33 34 private Consumer<Integer> mCallback = this::onUserSwitched; 35 CurrentUserTracker(Context context)36 public CurrentUserTracker(Context context) { 37 this(UserReceiver.getInstance(context)); 38 } 39 40 @VisibleForTesting CurrentUserTracker(UserReceiver receiver)41 CurrentUserTracker(UserReceiver receiver) { 42 mUserReceiver = receiver; 43 } 44 getCurrentUserId()45 public int getCurrentUserId() { 46 return mUserReceiver.getCurrentUserId(); 47 } 48 startTracking()49 public void startTracking() { 50 mUserReceiver.addTracker(mCallback); 51 } 52 stopTracking()53 public void stopTracking() { 54 mUserReceiver.removeTracker(mCallback); 55 } 56 onUserSwitched(int newUserId)57 public abstract void onUserSwitched(int newUserId); 58 59 @VisibleForTesting 60 static class UserReceiver extends BroadcastReceiver { 61 private static UserReceiver sInstance; 62 63 private Context mAppContext; 64 private boolean mReceiverRegistered; 65 private int mCurrentUserId; 66 67 private List<Consumer<Integer>> mCallbacks = new ArrayList<>(); 68 69 @VisibleForTesting UserReceiver(Context context)70 UserReceiver(Context context) { 71 mAppContext = context.getApplicationContext(); 72 } 73 getInstance(Context context)74 static UserReceiver getInstance(Context context) { 75 if (sInstance == null) { 76 sInstance = new UserReceiver(context); 77 } 78 return sInstance; 79 } 80 81 @Override onReceive(Context context, Intent intent)82 public void onReceive(Context context, Intent intent) { 83 if (Intent.ACTION_USER_SWITCHED.equals(intent.getAction())) { 84 notifyUserSwitched(intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0)); 85 } 86 } 87 getCurrentUserId()88 public int getCurrentUserId() { 89 return mCurrentUserId; 90 } 91 addTracker(Consumer<Integer> callback)92 private void addTracker(Consumer<Integer> callback) { 93 if (!mCallbacks.contains(callback)) { 94 mCallbacks.add(callback); 95 } 96 if (!mReceiverRegistered) { 97 mCurrentUserId = ActivityManager.getCurrentUser(); 98 IntentFilter filter = new IntentFilter(Intent.ACTION_USER_SWITCHED); 99 mAppContext.registerReceiver(this, filter); 100 mReceiverRegistered = true; 101 } 102 } 103 removeTracker(Consumer<Integer> callback)104 private void removeTracker(Consumer<Integer> callback) { 105 if (mCallbacks.contains(callback)) { 106 mCallbacks.remove(callback); 107 if (mCallbacks.size() == 0 && mReceiverRegistered) { 108 mAppContext.unregisterReceiver(this); 109 mReceiverRegistered = false; 110 } 111 } 112 } 113 notifyUserSwitched(int newUserId)114 private void notifyUserSwitched(int newUserId) { 115 if (mCurrentUserId != newUserId) { 116 mCurrentUserId = newUserId; 117 List<Consumer<Integer>> callbacks = new ArrayList<>(mCallbacks); 118 for (Consumer<Integer> consumer : callbacks) { 119 // Accepting may modify this list 120 if (mCallbacks.contains(consumer)) { 121 consumer.accept(newUserId); 122 } 123 } 124 } 125 } 126 } 127 } 128