1 /*
2  * Copyright (C) 2019 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.content.Context;
20 
21 import androidx.lifecycle.LiveData;
22 import androidx.lifecycle.MutableLiveData;
23 
24 /**
25  * A class that has an observable for the current user.
26  */
27 public class CurrentUserObservable {
28 
29     private final CurrentUserTracker mTracker;
30 
31     private final MutableLiveData<Integer> mCurrentUser = new MutableLiveData<Integer>() {
32         @Override
33         protected void onActive() {
34             super.onActive();
35             mTracker.startTracking();
36         }
37 
38         @Override
39         protected void onInactive() {
40             super.onInactive();
41             mTracker.startTracking();
42         }
43     };
44 
CurrentUserObservable(Context context)45     public CurrentUserObservable(Context context) {
46         mTracker = new CurrentUserTracker(context) {
47             @Override
48             public void onUserSwitched(int newUserId) {
49                 mCurrentUser.setValue(newUserId);
50             }
51         };
52     }
53 
54     /**
55      * Returns the current user that can be observed.
56      */
getCurrentUser()57     public LiveData<Integer> getCurrentUser() {
58         if (mCurrentUser.getValue() == null) {
59             mCurrentUser.setValue(mTracker.getCurrentUserId());
60         }
61         return mCurrentUser;
62     }
63 }
64