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.mtp;
18
19import android.app.Notification;
20import android.app.Service;
21import android.app.NotificationManager;
22import android.content.ComponentName;
23import android.content.Context;
24import android.content.Intent;
25import android.os.IBinder;
26import android.util.Log;
27
28import java.io.IOException;
29
30/**
31 * Service to manage lifetime of DocumentsProvider's process.
32 * The service prevents the system from killing the process that holds USB connections. The service
33 * starts to run when the first MTP device is opened, and stops when the last MTP device is closed.
34 */
35public class MtpDocumentsService extends Service {
36    static final String ACTION_OPEN_DEVICE = "com.android.mtp.OPEN_DEVICE";
37    static final String ACTION_CLOSE_DEVICE = "com.android.mtp.CLOSE_DEVICE";
38    static final String ACTION_UPDATE_NOTIFICATION = "com.android.mtp.UPDATE_NOTIFICATION";
39    static final String EXTRA_DEVICE = "device";
40
41    NotificationManager mNotificationManager;
42
43    @Override
44    public IBinder onBind(Intent intent) {
45        // The service is used via intents.
46        return null;
47    }
48
49    @Override
50    public void onCreate() {
51        super.onCreate();
52        mNotificationManager = getSystemService(NotificationManager.class);
53    }
54
55    @Override
56    public int onStartCommand(Intent intent, int flags, int startId) {
57        // If intent is null, the service was restarted.
58        if (intent == null || ACTION_UPDATE_NOTIFICATION.equals(intent.getAction())) {
59            return updateForegroundState() ? START_STICKY : START_NOT_STICKY;
60        }
61        return START_NOT_STICKY;
62    }
63
64    /**
65     * Updates the foreground state of the service.
66     * @return Whether the service is foreground or not.
67     */
68    private boolean updateForegroundState() {
69        final MtpDocumentsProvider provider = MtpDocumentsProvider.getInstance();
70        int notificationId = 0;
71        Notification notification = null;
72        // TODO: Hide notification if the device has already been removed.
73        for (final MtpDeviceRecord record : provider.getOpenedDeviceRecordsCache()) {
74            final String title = getResources().getString(
75                    R.string.accessing_notification_title,
76                    record.name);
77            notificationId = record.deviceId;
78            notification = new Notification.Builder(this)
79                    .setLocalOnly(true)
80                    .setContentTitle(title)
81                    .setSmallIcon(com.android.internal.R.drawable.stat_sys_data_usb)
82                    .setCategory(Notification.CATEGORY_SYSTEM)
83                    .setPriority(Notification.PRIORITY_LOW)
84                    .build();
85            mNotificationManager.notify(record.deviceId, notification);
86        }
87
88        if (notification != null) {
89            startForeground(notificationId, notification);
90            return true;
91        } else {
92            stopForeground(true /* removeNotification */);
93            stopSelf();
94            return false;
95        }
96    }
97
98    private static void logErrorMessage(Exception exp) {
99        if (exp.getMessage() != null) {
100            Log.e(MtpDocumentsProvider.TAG, exp.getMessage());
101        } else {
102            Log.e(MtpDocumentsProvider.TAG, exp.toString());
103        }
104    }
105}
106