1/*
2 * Copyright (C) 2013 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.server.wifi;
18
19import android.app.Notification;
20import android.app.NotificationManager;
21import android.app.TaskStackBuilder;
22import android.content.BroadcastReceiver;
23import android.content.Context;
24import android.content.Intent;
25import android.content.IntentFilter;
26import android.database.ContentObserver;
27import android.net.NetworkInfo;
28import android.net.wifi.ScanResult;
29import android.net.wifi.WifiManager;
30import android.net.wifi.WifiScanner;
31import android.os.Handler;
32import android.os.Looper;
33import android.os.Message;
34import android.os.UserHandle;
35import android.os.UserManager;
36import android.provider.Settings;
37
38import com.android.internal.notification.SystemNotificationChannels;
39
40import java.io.FileDescriptor;
41import java.io.PrintWriter;
42import java.util.List;
43
44/**
45 * Takes care of handling the "open wi-fi network available" notification
46 * @hide
47 */
48public class WifiNotificationController {
49    /**
50     * The icon to show in the 'available networks' notification. This will also
51     * be the ID of the Notification given to the NotificationManager.
52     */
53    private static final int ICON_NETWORKS_AVAILABLE =
54            com.android.internal.R.drawable.stat_notify_wifi_in_range;
55    /**
56     * When a notification is shown, we wait this amount before possibly showing it again.
57     */
58    private final long NOTIFICATION_REPEAT_DELAY_MS;
59
60    /**
61     * Whether the user has set the setting to show the 'available networks' notification.
62     */
63    private boolean mNotificationEnabled;
64    /**
65     * Observes the user setting to keep {@link #mNotificationEnabled} in sync.
66     */
67    private NotificationEnabledSettingObserver mNotificationEnabledSettingObserver;
68
69    /**
70     * The {@link System#currentTimeMillis()} must be at least this value for us
71     * to show the notification again.
72     */
73    private long mNotificationRepeatTime;
74    /**
75     * The Notification object given to the NotificationManager.
76     */
77    private Notification.Builder mNotificationBuilder;
78    /**
79     * Whether the notification is being shown, as set by us. That is, if the
80     * user cancels the notification, we will not receive the callback so this
81     * will still be true. We only guarantee if this is false, then the
82     * notification is not showing.
83     */
84    private boolean mNotificationShown;
85    /**
86     * The number of continuous scans that must occur before consider the
87     * supplicant in a scanning state. This allows supplicant to associate with
88     * remembered networks that are in the scan results.
89     */
90    private static final int NUM_SCANS_BEFORE_ACTUALLY_SCANNING = 3;
91    /**
92     * The number of scans since the last network state change. When this
93     * exceeds {@link #NUM_SCANS_BEFORE_ACTUALLY_SCANNING}, we consider the
94     * supplicant to actually be scanning. When the network state changes to
95     * something other than scanning, we reset this to 0.
96     */
97    private int mNumScansSinceNetworkStateChange;
98
99    private final Context mContext;
100    private NetworkInfo mNetworkInfo;
101    private NetworkInfo.DetailedState mDetailedState;
102    private volatile int mWifiState;
103    private FrameworkFacade mFrameworkFacade;
104    private WifiInjector mWifiInjector;
105    private WifiScanner mWifiScanner;
106
107    WifiNotificationController(Context context,
108                               Looper looper,
109                               FrameworkFacade framework,
110                               Notification.Builder builder,
111                               WifiInjector wifiInjector) {
112        mContext = context;
113        mFrameworkFacade = framework;
114        mNotificationBuilder = builder;
115        mWifiInjector = wifiInjector;
116        mWifiState = WifiManager.WIFI_STATE_UNKNOWN;
117        mDetailedState = NetworkInfo.DetailedState.IDLE;
118
119        IntentFilter filter = new IntentFilter();
120        filter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);
121        filter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
122        filter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
123
124        mContext.registerReceiver(
125                new BroadcastReceiver() {
126                    @Override
127                    public void onReceive(Context context, Intent intent) {
128                        if (intent.getAction()
129                                .equals(WifiManager.WIFI_STATE_CHANGED_ACTION)) {
130                            mWifiState = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE,
131                                    WifiManager.WIFI_STATE_UNKNOWN);
132                            resetNotification();
133                        } else if (intent.getAction().equals(
134                                WifiManager.NETWORK_STATE_CHANGED_ACTION)) {
135                            mNetworkInfo = (NetworkInfo) intent.getParcelableExtra(
136                                    WifiManager.EXTRA_NETWORK_INFO);
137                            NetworkInfo.DetailedState detailedState =
138                                    mNetworkInfo.getDetailedState();
139                            if (detailedState != NetworkInfo.DetailedState.SCANNING
140                                    && detailedState != mDetailedState) {
141                                mDetailedState = detailedState;
142                                // reset & clear notification on a network connect & disconnect
143                                switch(mDetailedState) {
144                                    case CONNECTED:
145                                    case DISCONNECTED:
146                                    case CAPTIVE_PORTAL_CHECK:
147                                        resetNotification();
148                                        break;
149
150                                    case IDLE:
151                                    case SCANNING:
152                                    case CONNECTING:
153                                    case AUTHENTICATING:
154                                    case OBTAINING_IPADDR:
155                                    case SUSPENDED:
156                                    case FAILED:
157                                    case BLOCKED:
158                                    case VERIFYING_POOR_LINK:
159                                        break;
160                                }
161                            }
162                        } else if (intent.getAction().equals(
163                                WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)) {
164                            if (mWifiScanner == null) {
165                                mWifiScanner = mWifiInjector.getWifiScanner();
166                            }
167                            checkAndSetNotification(mNetworkInfo,
168                                    mWifiScanner.getSingleScanResults());
169                        }
170                    }
171                }, filter);
172
173        // Setting is in seconds
174        NOTIFICATION_REPEAT_DELAY_MS = mFrameworkFacade.getIntegerSetting(context,
175                Settings.Global.WIFI_NETWORKS_AVAILABLE_REPEAT_DELAY, 900) * 1000L;
176        mNotificationEnabledSettingObserver = new NotificationEnabledSettingObserver(
177                new Handler(looper));
178        mNotificationEnabledSettingObserver.register();
179    }
180
181    private synchronized void checkAndSetNotification(NetworkInfo networkInfo,
182            List<ScanResult> scanResults) {
183
184        // TODO: unregister broadcast so we do not have to check here
185        // If we shouldn't place a notification on available networks, then
186        // don't bother doing any of the following
187        if (!mNotificationEnabled) return;
188        if (mWifiState != WifiManager.WIFI_STATE_ENABLED) return;
189        if (UserManager.get(mContext)
190                .hasUserRestriction(UserManager.DISALLOW_CONFIG_WIFI, UserHandle.CURRENT)) {
191            return;
192        }
193
194        NetworkInfo.State state = NetworkInfo.State.DISCONNECTED;
195        if (networkInfo != null)
196            state = networkInfo.getState();
197
198        if ((state == NetworkInfo.State.DISCONNECTED)
199                || (state == NetworkInfo.State.UNKNOWN)) {
200            if (scanResults != null) {
201                int numOpenNetworks = 0;
202                for (int i = scanResults.size() - 1; i >= 0; i--) {
203                    ScanResult scanResult = scanResults.get(i);
204
205                    //A capability of [ESS] represents an open access point
206                    //that is available for an STA to connect
207                    if (scanResult.capabilities != null &&
208                            scanResult.capabilities.equals("[ESS]")) {
209                        numOpenNetworks++;
210                    }
211                }
212
213                if (numOpenNetworks > 0) {
214                    if (++mNumScansSinceNetworkStateChange >= NUM_SCANS_BEFORE_ACTUALLY_SCANNING) {
215                        /*
216                         * We've scanned continuously at least
217                         * NUM_SCANS_BEFORE_NOTIFICATION times. The user
218                         * probably does not have a remembered network in range,
219                         * since otherwise supplicant would have tried to
220                         * associate and thus resetting this counter.
221                         */
222                        setNotificationVisible(true, numOpenNetworks, false, 0);
223                    }
224                    return;
225                }
226            }
227        }
228
229        // No open networks in range, remove the notification
230        setNotificationVisible(false, 0, false, 0);
231    }
232
233    /**
234     * Clears variables related to tracking whether a notification has been
235     * shown recently and clears the current notification.
236     */
237    private synchronized void resetNotification() {
238        mNotificationRepeatTime = 0;
239        mNumScansSinceNetworkStateChange = 0;
240        setNotificationVisible(false, 0, false, 0);
241    }
242
243    /**
244     * Display or don't display a notification that there are open Wi-Fi networks.
245     * @param visible {@code true} if notification should be visible, {@code false} otherwise
246     * @param numNetworks the number networks seen
247     * @param force {@code true} to force notification to be shown/not-shown,
248     * even if it is already shown/not-shown.
249     * @param delay time in milliseconds after which the notification should be made
250     * visible or invisible.
251     */
252    private void setNotificationVisible(boolean visible, int numNetworks, boolean force,
253            int delay) {
254
255        // Since we use auto cancel on the notification, when the
256        // mNetworksAvailableNotificationShown is true, the notification may
257        // have actually been canceled.  However, when it is false we know
258        // for sure that it is not being shown (it will not be shown any other
259        // place than here)
260
261        // If it should be hidden and it is already hidden, then noop
262        if (!visible && !mNotificationShown && !force) {
263            return;
264        }
265
266        NotificationManager notificationManager = (NotificationManager) mContext
267                .getSystemService(Context.NOTIFICATION_SERVICE);
268
269        Message message;
270        if (visible) {
271
272            // Not enough time has passed to show the notification again
273            if (System.currentTimeMillis() < mNotificationRepeatTime) {
274                return;
275            }
276
277            if (mNotificationBuilder == null) {
278                // Cache the Notification builder object.
279                mNotificationBuilder = new Notification.Builder(mContext,
280                        SystemNotificationChannels.NETWORK_AVAILABLE)
281                        .setWhen(0)
282                        .setSmallIcon(ICON_NETWORKS_AVAILABLE)
283                        .setAutoCancel(true)
284                        .setContentIntent(TaskStackBuilder.create(mContext)
285                                .addNextIntentWithParentStack(
286                                        new Intent(WifiManager.ACTION_PICK_WIFI_NETWORK))
287                                .getPendingIntent(0, 0, null, UserHandle.CURRENT))
288                        .setColor(mContext.getResources().getColor(
289                                com.android.internal.R.color.system_notification_accent_color));
290            }
291
292            CharSequence title = mContext.getResources().getQuantityText(
293                    com.android.internal.R.plurals.wifi_available, numNetworks);
294            CharSequence details = mContext.getResources().getQuantityText(
295                    com.android.internal.R.plurals.wifi_available_detailed, numNetworks);
296            mNotificationBuilder.setTicker(title);
297            mNotificationBuilder.setContentTitle(title);
298            mNotificationBuilder.setContentText(details);
299
300            mNotificationRepeatTime = System.currentTimeMillis() + NOTIFICATION_REPEAT_DELAY_MS;
301
302            notificationManager.notifyAsUser(null, ICON_NETWORKS_AVAILABLE,
303                    mNotificationBuilder.build(), UserHandle.ALL);
304        } else {
305            notificationManager.cancelAsUser(null, ICON_NETWORKS_AVAILABLE, UserHandle.ALL);
306        }
307
308        mNotificationShown = visible;
309    }
310
311    void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
312        pw.println("mNotificationEnabled " + mNotificationEnabled);
313        pw.println("mNotificationRepeatTime " + mNotificationRepeatTime);
314        pw.println("mNotificationShown " + mNotificationShown);
315        pw.println("mNumScansSinceNetworkStateChange " + mNumScansSinceNetworkStateChange);
316    }
317
318    private class NotificationEnabledSettingObserver extends ContentObserver {
319        public NotificationEnabledSettingObserver(Handler handler) {
320            super(handler);
321        }
322
323        public void register() {
324            mFrameworkFacade.registerContentObserver(mContext, Settings.Global.getUriFor(
325                    Settings.Global.WIFI_NETWORKS_AVAILABLE_NOTIFICATION_ON), true, this);
326            synchronized (WifiNotificationController.this) {
327                mNotificationEnabled = getValue();
328            }
329        }
330
331        @Override
332        public void onChange(boolean selfChange) {
333            super.onChange(selfChange);
334
335            synchronized (WifiNotificationController.this) {
336                mNotificationEnabled = getValue();
337                resetNotification();
338            }
339        }
340
341        private boolean getValue() {
342            return mFrameworkFacade.getIntegerSetting(mContext,
343                    Settings.Global.WIFI_NETWORKS_AVAILABLE_NOTIFICATION_ON, 1) == 1;
344        }
345    }
346}
347