WifiSettingsStore.java revision a07c419913bfae2a896fbc29e8f269ee08c4d910 
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.content.ContentResolver;
20import android.content.Context;
21import android.provider.Settings;
22
23import java.io.FileDescriptor;
24import java.io.PrintWriter;
25
26/* Tracks persisted settings for Wi-Fi and airplane mode interaction */
27final class WifiSettingsStore {
28    /* Values tracked in Settings.Global.WIFI_ON */
29    private static final int WIFI_DISABLED                      = 0;
30    private static final int WIFI_ENABLED                       = 1;
31    /* Wifi enabled while in airplane mode */
32    private static final int WIFI_ENABLED_AIRPLANE_OVERRIDE     = 2;
33    /* Wifi disabled due to airplane mode on */
34    private static final int WIFI_DISABLED_AIRPLANE_ON          = 3;
35
36    /* Persisted state that tracks the wifi & airplane interaction from settings */
37    private int mPersistWifiState = WIFI_DISABLED;
38    /* Tracks current airplane mode state */
39    private boolean mAirplaneModeOn = false;
40
41    /* Tracks the setting of scan being available even when wi-fi is turned off
42     */
43    private boolean mScanAlwaysAvailable;
44
45    private final Context mContext;
46
47    /* Tracks if we have checked the saved wi-fi state after boot */
48    private boolean mCheckSavedStateAtBoot = false;
49
50    WifiSettingsStore(Context context) {
51        mContext = context;
52        mAirplaneModeOn = getPersistedAirplaneModeOn();
53        mPersistWifiState = getPersistedWifiState();
54        mScanAlwaysAvailable = getPersistedScanAlwaysAvailable();
55    }
56
57    synchronized boolean isWifiToggleEnabled() {
58        if (!mCheckSavedStateAtBoot) {
59            mCheckSavedStateAtBoot = true;
60            if (testAndClearWifiSavedState()) return true;
61        }
62
63        if (mAirplaneModeOn) {
64            return mPersistWifiState == WIFI_ENABLED_AIRPLANE_OVERRIDE;
65        } else {
66            return mPersistWifiState != WIFI_DISABLED;
67        }
68    }
69
70    /**
71     * Returns true if airplane mode is currently on.
72     * @return {@code true} if airplane mode is on.
73     */
74    synchronized boolean isAirplaneModeOn() {
75       return mAirplaneModeOn;
76    }
77
78    synchronized boolean isScanAlwaysAvailable() {
79        return mScanAlwaysAvailable;
80    }
81
82    synchronized boolean handleWifiToggled(boolean wifiEnabled) {
83        // Can Wi-Fi be toggled in airplane mode ?
84        if (mAirplaneModeOn && !isAirplaneToggleable()) {
85            return false;
86        }
87
88        if (wifiEnabled) {
89            if (mAirplaneModeOn) {
90                persistWifiState(WIFI_ENABLED_AIRPLANE_OVERRIDE);
91            } else {
92                persistWifiState(WIFI_ENABLED);
93            }
94        } else {
95            // When wifi state is disabled, we do not care
96            // if airplane mode is on or not. The scenario of
97            // wifi being disabled due to airplane mode being turned on
98            // is handled handleAirplaneModeToggled()
99            persistWifiState(WIFI_DISABLED);
100        }
101        return true;
102    }
103
104    synchronized boolean handleAirplaneModeToggled() {
105        // Is Wi-Fi sensitive to airplane mode changes ?
106        if (!isAirplaneSensitive()) {
107            return false;
108        }
109
110        mAirplaneModeOn = getPersistedAirplaneModeOn();
111        if (mAirplaneModeOn) {
112            // Wifi disabled due to airplane on
113            if (mPersistWifiState == WIFI_ENABLED) {
114                persistWifiState(WIFI_DISABLED_AIRPLANE_ON);
115            }
116        } else {
117            /* On airplane mode disable, restore wifi state if necessary */
118            if (testAndClearWifiSavedState() ||
119                    mPersistWifiState == WIFI_ENABLED_AIRPLANE_OVERRIDE) {
120                persistWifiState(WIFI_ENABLED);
121            }
122        }
123        return true;
124    }
125
126    synchronized void handleWifiScanAlwaysAvailableToggled() {
127        mScanAlwaysAvailable = getPersistedScanAlwaysAvailable();
128    }
129
130    void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
131        pw.println("mPersistWifiState " + mPersistWifiState);
132        pw.println("mAirplaneModeOn " + mAirplaneModeOn);
133    }
134
135    private void persistWifiState(int state) {
136        final ContentResolver cr = mContext.getContentResolver();
137        mPersistWifiState = state;
138        Settings.Global.putInt(cr, Settings.Global.WIFI_ON, state);
139    }
140
141    /* Does Wi-Fi need to be disabled when airplane mode is on ? */
142    private boolean isAirplaneSensitive() {
143        String airplaneModeRadios = Settings.Global.getString(mContext.getContentResolver(),
144                Settings.Global.AIRPLANE_MODE_RADIOS);
145        return airplaneModeRadios == null
146                || airplaneModeRadios.contains(Settings.Global.RADIO_WIFI);
147    }
148
149    /* Is Wi-Fi allowed to be re-enabled while airplane mode is on ? */
150    private boolean isAirplaneToggleable() {
151        String toggleableRadios = Settings.Global.getString(mContext.getContentResolver(),
152                Settings.Global.AIRPLANE_MODE_TOGGLEABLE_RADIOS);
153        return toggleableRadios != null
154                && toggleableRadios.contains(Settings.Global.RADIO_WIFI);
155    }
156
157     /* After a reboot, we restore wi-fi to be on if it was turned off temporarily for tethering.
158      * The settings app tracks the saved state, but the framework has to check it at boot to
159      * make sure the wi-fi is turned on in case it was turned off for the purpose of tethering.
160      *
161      * Note that this is not part of the regular WIFI_ON setting because this only needs to
162      * be controlled through the settings app and not the Wi-Fi public API.
163      */
164    private boolean testAndClearWifiSavedState() {
165        final ContentResolver cr = mContext.getContentResolver();
166        int wifiSavedState = 0;
167        try {
168            wifiSavedState = Settings.Global.getInt(cr, Settings.Global.WIFI_SAVED_STATE);
169            if(wifiSavedState == 1)
170                Settings.Global.putInt(cr, Settings.Global.WIFI_SAVED_STATE, 0);
171        } catch (Settings.SettingNotFoundException e) {
172            ;
173        }
174        return (wifiSavedState == 1);
175    }
176
177    private int getPersistedWifiState() {
178        final ContentResolver cr = mContext.getContentResolver();
179        try {
180            return Settings.Global.getInt(cr, Settings.Global.WIFI_ON);
181        } catch (Settings.SettingNotFoundException e) {
182            Settings.Global.putInt(cr, Settings.Global.WIFI_ON, WIFI_DISABLED);
183            return WIFI_DISABLED;
184        }
185    }
186
187    private boolean getPersistedAirplaneModeOn() {
188        return Settings.Global.getInt(mContext.getContentResolver(),
189                Settings.Global.AIRPLANE_MODE_ON, 0) == 1;
190    }
191
192    private boolean getPersistedScanAlwaysAvailable() {
193        return Settings.Global.getInt(mContext.getContentResolver(),
194                Settings.Global.WIFI_SCAN_ALWAYS_AVAILABLE,
195                0) == 1;
196    }
197}
198