/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.server.wifi;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.TaskStackBuilder;
import android.content.BroadcastReceiver;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.database.ContentObserver;
import android.net.NetworkInfo;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiManager;
import android.os.Handler;
import android.os.Message;
import android.os.UserHandle;
import android.provider.Settings;
import java.io.FileDescriptor;
import java.io.PrintWriter;
import java.util.List;
/* Takes care of handling the "open wi-fi network available" notification @hide */
final class WifiNotificationController {
/**
* The icon to show in the 'available networks' notification. This will also
* be the ID of the Notification given to the NotificationManager.
*/
private static final int ICON_NETWORKS_AVAILABLE =
com.android.internal.R.drawable.stat_notify_wifi_in_range;
/**
* When a notification is shown, we wait this amount before possibly showing it again.
*/
private final long NOTIFICATION_REPEAT_DELAY_MS;
/**
* Whether the user has set the setting to show the 'available networks' notification.
*/
private boolean mNotificationEnabled;
/**
* Observes the user setting to keep {@link #mNotificationEnabled} in sync.
*/
private NotificationEnabledSettingObserver mNotificationEnabledSettingObserver;
/**
* The {@link System#currentTimeMillis()} must be at least this value for us
* to show the notification again.
*/
private long mNotificationRepeatTime;
/**
* The Notification object given to the NotificationManager.
*/
private Notification.Builder mNotificationBuilder;
/**
* Whether the notification is being shown, as set by us. That is, if the
* user cancels the notification, we will not receive the callback so this
* will still be true. We only guarantee if this is false, then the
* notification is not showing.
*/
private boolean mNotificationShown;
/**
* The number of continuous scans that must occur before consider the
* supplicant in a scanning state. This allows supplicant to associate with
* remembered networks that are in the scan results.
*/
private static final int NUM_SCANS_BEFORE_ACTUALLY_SCANNING = 3;
/**
* The number of scans since the last network state change. When this
* exceeds {@link #NUM_SCANS_BEFORE_ACTUALLY_SCANNING}, we consider the
* supplicant to actually be scanning. When the network state changes to
* something other than scanning, we reset this to 0.
*/
private int mNumScansSinceNetworkStateChange;
private final Context mContext;
private final WifiStateMachine mWifiStateMachine;
private NetworkInfo mNetworkInfo;
private volatile int mWifiState;
WifiNotificationController(Context context, WifiStateMachine wsm) {
mContext = context;
mWifiStateMachine = wsm;
mWifiState = WifiManager.WIFI_STATE_UNKNOWN;
IntentFilter filter = new IntentFilter();
filter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);
filter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
filter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
mContext.registerReceiver(
new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(WifiManager.WIFI_STATE_CHANGED_ACTION)) {
mWifiState = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE,
WifiManager.WIFI_STATE_UNKNOWN);
resetNotification();
} else if (intent.getAction().equals(
WifiManager.NETWORK_STATE_CHANGED_ACTION)) {
mNetworkInfo = (NetworkInfo) intent.getParcelableExtra(
WifiManager.EXTRA_NETWORK_INFO);
// reset & clear notification on a network connect & disconnect
switch(mNetworkInfo.getDetailedState()) {
case CONNECTED:
case DISCONNECTED:
case CAPTIVE_PORTAL_CHECK:
resetNotification();
break;
}
} else if (intent.getAction().equals(
WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)) {
checkAndSetNotification(mNetworkInfo,
mWifiStateMachine.syncGetScanResultsList());
}
}
}, filter);
// Setting is in seconds
NOTIFICATION_REPEAT_DELAY_MS = Settings.Global.getInt(context.getContentResolver(),
Settings.Global.WIFI_NETWORKS_AVAILABLE_REPEAT_DELAY, 900) * 1000l;
mNotificationEnabledSettingObserver = new NotificationEnabledSettingObserver(new Handler());
mNotificationEnabledSettingObserver.register();
}
private synchronized void checkAndSetNotification(NetworkInfo networkInfo,
List<ScanResult> scanResults) {
// TODO: unregister broadcast so we do not have to check here
// If we shouldn't place a notification on available networks, then
// don't bother doing any of the following
if (!mNotificationEnabled) return;
if (mWifiState != WifiManager.WIFI_STATE_ENABLED) return;
NetworkInfo.State state = NetworkInfo.State.DISCONNECTED;
if (networkInfo != null)
state = networkInfo.getState();
if ((state == NetworkInfo.State.DISCONNECTED)
|| (state == NetworkInfo.State.UNKNOWN)) {
if (scanResults != null) {
int numOpenNetworks = 0;
for (int i = scanResults.size() - 1; i >= 0; i--) {
ScanResult scanResult = scanResults.get(i);
//A capability of [ESS] represents an open access point
//that is available for an STA to connect
if (scanResult.capabilities != null &&
scanResult.capabilities.equals("[ESS]")) {
numOpenNetworks++;
}
}
if (numOpenNetworks > 0) {
if (++mNumScansSinceNetworkStateChange >= NUM_SCANS_BEFORE_ACTUALLY_SCANNING) {
/*
* We've scanned continuously at least
* NUM_SCANS_BEFORE_NOTIFICATION times. The user
* probably does not have a remembered network in range,
* since otherwise supplicant would have tried to
* associate and thus resetting this counter.
*/
setNotificationVisible(true, numOpenNetworks, false, 0);
}
return;
}
}
}
// No open networks in range, remove the notification
setNotificationVisible(false, 0, false, 0);
}
/**
* Clears variables related to tracking whether a notification has been
* shown recently and clears the current notification.
*/
private synchronized void resetNotification() {
mNotificationRepeatTime = 0;
mNumScansSinceNetworkStateChange = 0;
setNotificationVisible(false, 0, false, 0);
}
/**
* Display or don't display a notification that there are open Wi-Fi networks.
* @param visible {@code true} if notification should be visible, {@code false} otherwise
* @param numNetworks the number networks seen
* @param force {@code true} to force notification to be shown/not-shown,
* even if it is already shown/not-shown.
* @param delay time in milliseconds after which the notification should be made
* visible or invisible.
*/
private void setNotificationVisible(boolean visible, int numNetworks, boolean force,
int delay) {
// Since we use auto cancel on the notification, when the
// mNetworksAvailableNotificationShown is true, the notification may
// have actually been canceled. However, when it is false we know
// for sure that it is not being shown (it will not be shown any other
// place than here)
// If it should be hidden and it is already hidden, then noop
if (!visible && !mNotificationShown && !force) {
return;
}
NotificationManager notificationManager = (NotificationManager) mContext
.getSystemService(Context.NOTIFICATION_SERVICE);
Message message;
if (visible) {
// Not enough time has passed to show the notification again
if (System.currentTimeMillis() < mNotificationRepeatTime) {
return;
}
if (mNotificationBuilder == null) {
// Cache the Notification builder object.
mNotificationBuilder = new Notification.Builder(mContext)
.setWhen(0)
.setSmallIcon(ICON_NETWORKS_AVAILABLE)
.setAutoCancel(true)
.setContentIntent(TaskStackBuilder.create(mContext)
.addNextIntentWithParentStack(
new Intent(WifiManager.ACTION_PICK_WIFI_NETWORK))
.getPendingIntent(0, 0, null, UserHandle.CURRENT))
.setColor(mContext.getResources().getColor(
com.android.internal.R.color.system_notification_accent_color));
}
CharSequence title = mContext.getResources().getQuantityText(
com.android.internal.R.plurals.wifi_available, numNetworks);
CharSequence details = mContext.getResources().getQuantityText(
com.android.internal.R.plurals.wifi_available_detailed, numNetworks);
mNotificationBuilder.setTicker(title);
mNotificationBuilder.setContentTitle(title);
mNotificationBuilder.setContentText(details);
mNotificationRepeatTime = System.currentTimeMillis() + NOTIFICATION_REPEAT_DELAY_MS;
notificationManager.notifyAsUser(null, ICON_NETWORKS_AVAILABLE,
mNotificationBuilder.build(), UserHandle.ALL);
} else {
notificationManager.cancelAsUser(null, ICON_NETWORKS_AVAILABLE, UserHandle.ALL);
}
mNotificationShown = visible;
}
void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
pw.println("mNotificationEnabled " + mNotificationEnabled);
pw.println("mNotificationRepeatTime " + mNotificationRepeatTime);
pw.println("mNotificationShown " + mNotificationShown);
pw.println("mNumScansSinceNetworkStateChange " + mNumScansSinceNetworkStateChange);
}
private class NotificationEnabledSettingObserver extends ContentObserver {
public NotificationEnabledSettingObserver(Handler handler) {
super(handler);
}
public void register() {
ContentResolver cr = mContext.getContentResolver();
cr.registerContentObserver(Settings.Global.getUriFor(
Settings.Global.WIFI_NETWORKS_AVAILABLE_NOTIFICATION_ON), true, this);
synchronized (WifiNotificationController.this) {
mNotificationEnabled = getValue();
}
}
@Override
public void onChange(boolean selfChange) {
super.onChange(selfChange);
synchronized (WifiNotificationController.this) {
mNotificationEnabled = getValue();
resetNotification();
}
}
private boolean getValue() {
return Settings.Global.getInt(mContext.getContentResolver(),
Settings.Global.WIFI_NETWORKS_AVAILABLE_NOTIFICATION_ON, 1) == 1;
}
}
}