1 /**
2  * Copyright (c) 2018 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.example.android.multidisplay.launcher;
18 
19 import static com.example.android.multidisplay.launcher.PinnedAppListViewModel.PINNED_APPS_KEY;
20 
21 import android.app.Application;
22 import android.content.ComponentName;
23 import android.content.Context;
24 import android.content.Intent;
25 import android.content.pm.PackageManager;
26 import android.content.pm.ResolveInfo;
27 import android.content.SharedPreferences;
28 import android.os.AsyncTask;
29 
30 import androidx.lifecycle.AndroidViewModel;
31 import androidx.lifecycle.LiveData;
32 
33 import java.util.ArrayList;
34 import java.util.List;
35 import java.util.Set;
36 
37 /**
38  * A view model that provides a list of activities that were pinned by user to always display on
39  * home screen.
40  * The pinned activities are stored in {@link SharedPreferences} to keep the sample simple :).
41  */
42 public class PinnedAppListViewModel extends AndroidViewModel {
43 
44     final static String PINNED_APPS_KEY = "pinned_apps";
45 
46     private final PinnedAppListLiveData mLiveData;
47 
PinnedAppListViewModel(Application application)48     public PinnedAppListViewModel(Application application) {
49         super(application);
50         mLiveData = new PinnedAppListLiveData(application);
51     }
52 
getPinnedAppList()53     public LiveData<List<AppEntry>> getPinnedAppList() {
54         return mLiveData;
55     }
56 }
57 
58 class PinnedAppListLiveData extends LiveData<List<AppEntry>> {
59 
60     private final Context mContext;
61     private final PackageManager mPackageManager;
62     // Store listener reference, so it won't be GC-ed.
63     private final SharedPreferences.OnSharedPreferenceChangeListener mChangeListener;
64     private int mCurrentDataVersion;
65 
PinnedAppListLiveData(Context context)66     public PinnedAppListLiveData(Context context) {
67         mContext = context;
68         mPackageManager = context.getPackageManager();
69 
70         final SharedPreferences prefs = context.getSharedPreferences(PINNED_APPS_KEY, 0);
71         mChangeListener = (preferences, key) -> {
72             loadData();
73         };
74         prefs.registerOnSharedPreferenceChangeListener(mChangeListener);
75 
76         loadData();
77     }
78 
loadData()79     private void loadData() {
80         final int loadDataVersion = ++mCurrentDataVersion;
81 
82         new AsyncTask<Void, Void, List<AppEntry>>() {
83             @Override
84             protected List<AppEntry> doInBackground(Void... voids) {
85                 List<AppEntry> entries = new ArrayList<>();
86 
87                 final SharedPreferences sp = mContext.getSharedPreferences(PINNED_APPS_KEY, 0);
88                 final Set<String> pinnedAppsComponents = sp.getStringSet(PINNED_APPS_KEY, null);
89                 if (pinnedAppsComponents == null) {
90                     return null;
91                 }
92 
93                 for (String componentString : pinnedAppsComponents) {
94                     final Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
95                     mainIntent.setComponent(ComponentName.unflattenFromString(componentString));
96                     mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);
97 
98                     final List<ResolveInfo> apps = mPackageManager.queryIntentActivities(mainIntent,
99                             PackageManager.GET_META_DATA);
100 
101                     if (apps != null) {
102                         for (ResolveInfo app : apps) {
103                             final AppEntry entry = new AppEntry(app, mPackageManager);
104                             entries.add(entry);
105                         }
106                     }
107                 }
108 
109                 return entries;
110             }
111 
112             @Override
113             protected void onPostExecute(List<AppEntry> data) {
114                 if (mCurrentDataVersion == loadDataVersion) {
115                     setValue(data);
116                 }
117             }
118         }.execute();
119     }
120 }