DeskClockBackupAgent.java revision 4a025d30d308222b78ed68897da89e2b264a5fb8 
1/*
2 * Copyright (C) 2015 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
17package com.android.deskclock;
18
19import android.app.AlarmManager;
20import android.app.PendingIntent;
21import android.app.backup.BackupAgent;
22import android.app.backup.BackupDataInput;
23import android.app.backup.BackupDataOutput;
24import android.content.ContentResolver;
25import android.content.Context;
26import android.content.Intent;
27import android.content.IntentFilter;
28import android.content.SharedPreferences;
29import android.os.ParcelFileDescriptor;
30import android.os.SystemClock;
31import android.preference.PreferenceManager;
32import android.support.annotation.NonNull;
33
34import com.android.deskclock.alarms.AlarmStateManager;
35import com.android.deskclock.provider.Alarm;
36import com.android.deskclock.provider.AlarmInstance;
37
38import java.io.File;
39import java.io.IOException;
40import java.util.Calendar;
41import java.util.List;
42
43public class DeskClockBackupAgent extends BackupAgent {
44
45    private static final String KEY_RESTORE_FINISHED = "restore_finished";
46
47    public static final String ACTION_COMPLETE_RESTORE =
48            "com.android.deskclock.action.COMPLETE_RESTORE";
49
50    private static final String TAG = "DeskClockBackupAgent";
51
52    @Override
53    public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data,
54            ParcelFileDescriptor newState) throws IOException { }
55
56    @Override
57    public void onRestore(BackupDataInput data, int appVersionCode,
58            ParcelFileDescriptor newState) throws IOException { }
59
60    @Override
61    public void onRestoreFile(@NonNull ParcelFileDescriptor data, long size, File destination,
62            int type, long mode, long mtime) throws IOException {
63        // The preference file on the backup device may not be the same on the restore device.
64        // Massage the file name here before writing it.
65        if (destination.getName().endsWith("_preferences.xml")) {
66            final String prefFileName = getPackageName() + "_preferences.xml";
67            destination = new File(destination.getParentFile(), prefFileName);
68        }
69
70        super.onRestoreFile(data, size, destination, type, mode, mtime);
71    }
72
73    /**
74     * When this method is called during backup/restore, the application is executing in a
75     * "minimalist" state. Because of this, the application's ContentResolver cannot be used.
76     * Consequently, the work of scheduling alarms on the restore device cannot be done here.
77     * Instead, a future callback to DeskClock is used as a signal to reschedule the alarms. The
78     * future callback may take the form of ACTION_BOOT_COMPLETED if the device is not yet fully
79     * booted (i.e. the restore occurred as part of the setup wizard). If the device is booted, an
80     * ACTION_COMPLETE_RESTORE broadcast is scheduled 10 seconds in the future to give
81     * backup/restore enough time to kill the Clock process. Both of these future callbacks result
82     * in the execution of {@link #processRestoredData(Context)}.
83     */
84    @Override
85    public void onRestoreFinished() {
86        if (Utils.isNOrLater()) {
87            // TODO: migrate restored database and preferences over into
88            // the device-encrypted storage area
89        }
90
91        // Write a preference to indicate a data restore has been completed.
92        final SharedPreferences prefs = Utils.getDefaultSharedPreferences(this);
93        prefs.edit().putBoolean(KEY_RESTORE_FINISHED, true).apply();
94
95        // Create an Intent to send into DeskClock indicating restore is complete.
96        final PendingIntent restoreIntent = PendingIntent.getBroadcast(this, 0,
97                new Intent(ACTION_COMPLETE_RESTORE).setClass(this, AlarmInitReceiver.class),
98                PendingIntent.FLAG_ONE_SHOT | PendingIntent.FLAG_CANCEL_CURRENT);
99
100        // Deliver the Intent 10 seconds from now.
101        final long triggerAtMillis = SystemClock.elapsedRealtime() + 10000;
102
103        // Schedule the Intent delivery in AlarmManager.
104        final AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
105        alarmManager.setExact(AlarmManager.ELAPSED_REALTIME_WAKEUP, triggerAtMillis, restoreIntent);
106
107        LogUtils.i(TAG, "Waiting for %s to complete the data restore", ACTION_COMPLETE_RESTORE);
108    }
109
110    /**
111     * @param context a context to access resources and services
112     * @return {@code true} if restore data was processed; {@code false} otherwise.
113     */
114    public static boolean processRestoredData(Context context) {
115        // If the preference indicates data was not recently restored, there is nothing to do.
116        final SharedPreferences prefs = Utils.getDefaultSharedPreferences(context);
117        if (!prefs.getBoolean(KEY_RESTORE_FINISHED, false)) {
118            return false;
119        }
120
121        LogUtils.i(TAG, "processRestoredData() started");
122
123        // Now that alarms have been restored, schedule new instances in AlarmManager.
124        final ContentResolver contentResolver = context.getContentResolver();
125        final List<Alarm> alarms = Alarm.getAlarms(contentResolver, null);
126
127        final Calendar now = Calendar.getInstance();
128        for (Alarm alarm : alarms) {
129            // Remove any instances that may currently exist for the alarm;
130            // these aren't relevant on the restore device and we'll recreate them below.
131            AlarmStateManager.deleteAllInstances(context, alarm.id);
132
133            if (alarm.enabled) {
134                // Create the next alarm instance to schedule.
135                AlarmInstance alarmInstance = alarm.createInstanceAfter(now);
136
137                // Add the next alarm instance to the database.
138                alarmInstance = AlarmInstance.addInstance(contentResolver, alarmInstance);
139
140                // Schedule the next alarm instance in AlarmManager.
141                AlarmStateManager.registerInstance(context, alarmInstance, true);
142                LogUtils.i(TAG, "DeskClockBackupAgent scheduled alarm instance: %s", alarmInstance);
143            }
144        }
145
146        // Remove the preference to avoid executing this logic multiple times.
147        prefs.edit().remove(KEY_RESTORE_FINISHED).apply();
148
149        LogUtils.i(TAG, "processRestoredData() completed");
150        return true;
151    }
152}