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.packageinstaller.role.ui;
18 
19 import android.content.pm.ApplicationInfo;
20 import android.util.Pair;
21 
22 import androidx.annotation.NonNull;
23 import androidx.lifecycle.MediatorLiveData;
24 
25 import java.util.ArrayList;
26 import java.util.List;
27 
28 /**
29  * {@link MediatorLiveData} that merges multiple {@link RoleLiveData} instances.
30  */
31 public class MergeRoleLiveData extends MediatorLiveData<List<Pair<ApplicationInfo, Boolean>>> {
32 
33     @NonNull
34     private final RoleLiveData[] mLiveDatas;
35 
MergeRoleLiveData(@onNull RoleLiveData... liveDatas)36     public MergeRoleLiveData(@NonNull RoleLiveData... liveDatas) {
37         mLiveDatas = liveDatas;
38 
39         int liveDatasLength = mLiveDatas.length;
40         for (int i = 0; i < liveDatasLength; i++) {
41             RoleLiveData liveData = mLiveDatas[i];
42 
43             addSource(liveData, roleItems -> onRoleChanged());
44         }
45     }
46 
onRoleChanged()47     private void onRoleChanged() {
48         List<Pair<ApplicationInfo, Boolean>> mergedQualifyingApplications = new ArrayList<>();
49         int liveDatasLength = mLiveDatas.length;
50         for (int i = 0; i < liveDatasLength; i++) {
51             RoleLiveData liveData = mLiveDatas[i];
52 
53             List<Pair<ApplicationInfo, Boolean>> qualifyingApplications = liveData.getValue();
54             if (qualifyingApplications == null) {
55                 return;
56             }
57             mergedQualifyingApplications.addAll(qualifyingApplications);
58         }
59 
60         setValue(mergedQualifyingApplications);
61     }
62 }
63