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 */
27public class WifiSettingsStore {
28    /* Values tracked in Settings.Global.WIFI_ON */
29    static final int WIFI_DISABLED                      = 0;
30    static final int WIFI_ENABLED                       = 1;
31
32    /* Wifi enabled while in airplane mode */
33    private static final int WIFI_ENABLED_AIRPLANE_OVERRIDE     = 2;
34    /* Wifi disabled due to airplane mode on */
35    private static final int WIFI_DISABLED_AIRPLANE_ON          = 3;
36
37    /* Persisted state that tracks the wifi & airplane interaction from settings */
38    private int mPersistWifiState = WIFI_DISABLED;
39    /* Tracks current airplane mode state */
40    private boolean mAirplaneModeOn = false;
41
42    /* Tracks the setting of scan being available even when wi-fi is turned off
43     */
44    private boolean mScanAlwaysAvailable;
45
46    private final Context mContext;
47
48    /* Tracks if we have checked the saved wi-fi state after boot */
49    private boolean mCheckSavedStateAtBoot = false;
50
51    WifiSettingsStore(Context context) {
52        mContext = context;
53        mAirplaneModeOn = getPersistedAirplaneModeOn();
54        mPersistWifiState = getPersistedWifiState();
55        mScanAlwaysAvailable = getPersistedScanAlwaysAvailable();
56    }
57
58    public synchronized boolean isWifiToggleEnabled() {
59        if (!mCheckSavedStateAtBoot) {
60            mCheckSavedStateAtBoot = true;
61            if (testAndClearWifiSavedState()) return true;
62        }
63
64        if (mAirplaneModeOn) {
65            return mPersistWifiState == WIFI_ENABLED_AIRPLANE_OVERRIDE;
66        } else {
67            return mPersistWifiState != WIFI_DISABLED;
68        }
69    }
70
71    /**
72     * Returns true if airplane mode is currently on.
73     * @return {@code true} if airplane mode is on.
74     */
75    public synchronized boolean isAirplaneModeOn() {
76       return mAirplaneModeOn;
77    }
78
79    public synchronized boolean isScanAlwaysAvailable() {
80        return !mAirplaneModeOn && mScanAlwaysAvailable;
81    }
82
83    public synchronized boolean handleWifiToggled(boolean wifiEnabled) {
84        // Can Wi-Fi be toggled in airplane mode ?
85        if (mAirplaneModeOn && !isAirplaneToggleable()) {
86            return false;
87        }
88
89        if (wifiEnabled) {
90            if (mAirplaneModeOn) {
91                persistWifiState(WIFI_ENABLED_AIRPLANE_OVERRIDE);
92            } else {
93                persistWifiState(WIFI_ENABLED);
94            }
95        } else {
96            // When wifi state is disabled, we do not care
97            // if airplane mode is on or not. The scenario of
98            // wifi being disabled due to airplane mode being turned on
99            // is handled handleAirplaneModeToggled()
100            persistWifiState(WIFI_DISABLED);
101        }
102        return true;
103    }
104
105    synchronized boolean handleAirplaneModeToggled() {
106        // Is Wi-Fi sensitive to airplane mode changes ?
107        if (!isAirplaneSensitive()) {
108            return false;
109        }
110
111        mAirplaneModeOn = getPersistedAirplaneModeOn();
112        if (mAirplaneModeOn) {
113            // Wifi disabled due to airplane on
114            if (mPersistWifiState == WIFI_ENABLED) {
115                persistWifiState(WIFI_DISABLED_AIRPLANE_ON);
116            }
117        } else {
118            /* On airplane mode disable, restore wifi state if necessary */
119            if (testAndClearWifiSavedState() ||
120                    mPersistWifiState == WIFI_ENABLED_AIRPLANE_OVERRIDE) {
121                persistWifiState(WIFI_ENABLED);
122            }
123        }
124        return true;
125    }
126
127    synchronized void handleWifiScanAlwaysAvailableToggled() {
128        mScanAlwaysAvailable = getPersistedScanAlwaysAvailable();
129    }
130
131    void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
132        pw.println("mPersistWifiState " + mPersistWifiState);
133        pw.println("mAirplaneModeOn " + mAirplaneModeOn);
134    }
135
136    private void persistWifiState(int state) {
137        final ContentResolver cr = mContext.getContentResolver();
138        mPersistWifiState = state;
139        Settings.Global.putInt(cr, Settings.Global.WIFI_ON, state);
140    }
141
142    /* Does Wi-Fi need to be disabled when airplane mode is on ? */
143    private boolean isAirplaneSensitive() {
144        String airplaneModeRadios = Settings.Global.getString(mContext.getContentResolver(),
145                Settings.Global.AIRPLANE_MODE_RADIOS);
146        return airplaneModeRadios == null
147                || airplaneModeRadios.contains(Settings.Global.RADIO_WIFI);
148    }
149
150    /* Is Wi-Fi allowed to be re-enabled while airplane mode is on ? */
151    private boolean isAirplaneToggleable() {
152        String toggleableRadios = Settings.Global.getString(mContext.getContentResolver(),
153                Settings.Global.AIRPLANE_MODE_TOGGLEABLE_RADIOS);
154        return toggleableRadios != null
155                && toggleableRadios.contains(Settings.Global.RADIO_WIFI);
156    }
157
158    /**
159     * After a reboot, we restore wi-fi to be on if it was turned off temporarily for tethering.
160     * The settings app tracks the saved state, but the framework has to check it at boot to
161     * make sure the wi-fi is turned on in case it was turned off for the purpose of tethering.
162     *
163     * Note that this is not part of the regular WIFI_ON setting because this only needs to
164     * be controlled through the settings app and not the Wi-Fi public API.
165     */
166    private boolean testAndClearWifiSavedState() {
167        int wifiSavedState = getWifiSavedState();
168        if (wifiSavedState == WIFI_ENABLED) {
169            setWifiSavedState(WIFI_DISABLED);
170        }
171        return (wifiSavedState == WIFI_ENABLED);
172    }
173
174    /**
175     * Allow callers to set the Settings.Global.WIFI_SAVED_STATE property.
176     *
177     * When changing states, we need to remember what the wifi state was before switching.  An
178     * example of this is when WiFiController switches to APEnabledState.  Before swtiching to the
179     * new state, WifiController sets the current WiFi enabled/disabled state.  When the AP is
180     * turned off, the WIFI_SAVED_STATE setting is used to restore the previous wifi state.
181     *
182     * @param state WiFi state to store with the Settings.Global.WIFI_SAVED_STATE property.
183     */
184    public void setWifiSavedState(int state) {
185        Settings.Global.putInt(mContext.getContentResolver(),
186                Settings.Global.WIFI_SAVED_STATE, state);
187    }
188
189    /**
190     * Allow callers to get the Settings.Global.WIFI_SAVED_STATE property.
191     *
192     * When changing states we remember what the wifi state was before switching.  This function is
193     * used to get the saved state.
194     *
195     * @return int Value for the previously saved state.
196     */
197    public int getWifiSavedState() {
198        try {
199            return Settings.Global.getInt(mContext.getContentResolver(),
200                    Settings.Global.WIFI_SAVED_STATE);
201        } catch (Settings.SettingNotFoundException e) {
202            // If we have an error, return wifiSavedState off.
203            return WIFI_DISABLED;
204        }
205    }
206
207    private int getPersistedWifiState() {
208        final ContentResolver cr = mContext.getContentResolver();
209        try {
210            return Settings.Global.getInt(cr, Settings.Global.WIFI_ON);
211        } catch (Settings.SettingNotFoundException e) {
212            Settings.Global.putInt(cr, Settings.Global.WIFI_ON, WIFI_DISABLED);
213            return WIFI_DISABLED;
214        }
215    }
216
217    private boolean getPersistedAirplaneModeOn() {
218        return Settings.Global.getInt(mContext.getContentResolver(),
219                Settings.Global.AIRPLANE_MODE_ON, 0) == 1;
220    }
221
222    private boolean getPersistedScanAlwaysAvailable() {
223        return Settings.Global.getInt(mContext.getContentResolver(),
224                Settings.Global.WIFI_SCAN_ALWAYS_AVAILABLE,
225                0) == 1;
226    }
227}
228