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