Add a setting to disable Tor when running on battery

bramble-android/src/main/java/org/briarproject/bramble/battery/AndroidBatteryManager.java

@@ -19,9 +19,7 @@ import javax.inject.Inject;
 import static android.content.Intent.ACTION_BATTERY_CHANGED;
 import static android.content.Intent.ACTION_POWER_CONNECTED;
 import static android.content.Intent.ACTION_POWER_DISCONNECTED;
-import static android.os.BatteryManager.BATTERY_STATUS_CHARGING;
+import static android.os.BatteryManager.EXTRA_PLUGGED;
-import static android.os.BatteryManager.BATTERY_STATUS_FULL;
-import static android.os.BatteryManager.EXTRA_STATUS;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Logger.getLogger;
 
@@ -48,9 +46,8 @@ class AndroidBatteryManager implements BatteryManager, Service {
 		IntentFilter filter = new IntentFilter(ACTION_BATTERY_CHANGED);
 		Intent i = appContext.registerReceiver(null, filter);
 		if (i == null) return false;
-		int status = i.getIntExtra(EXTRA_STATUS, -1);
+		int status = i.getIntExtra(EXTRA_PLUGGED, 0);
-		return status == BATTERY_STATUS_CHARGING ||
+		return status != 0;
-				status == BATTERY_STATUS_FULL;
 	}
 
 	@Override

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/TorConstants.java

@@ -16,6 +16,7 @@ public interface TorConstants {
 	String PREF_TOR_NETWORK = "network2";
 	String PREF_TOR_PORT = "port";
 	String PREF_TOR_MOBILE = "useMobileData";
+	String PREF_TOR_ONLY_WHEN_CHARGING = "onlyWhenCharging";
 
 	int PREF_TOR_NETWORK_AUTOMATIC = 0;
 	int PREF_TOR_NETWORK_WITHOUT_BRIDGES = 1;

bramble-core/src/main/java/org/briarproject/bramble/plugin/tor/TorPlugin.java

@@ -69,6 +69,7 @@ import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_AUTOMATIC;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_NEVER;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_WITH_BRIDGES;
+import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_ONLY_WHEN_CHARGING;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_PORT;
 import static org.briarproject.bramble.api.plugin.TorConstants.PROP_ONION_V2;
 import static org.briarproject.bramble.api.plugin.TorConstants.PROP_ONION_V3;
@@ -648,8 +649,10 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			if (s.getNamespace().equals(ID.getString())) {
 				LOG.info("Tor settings updated");
 				settings = s.getSettings();
-				// Works around a bug introduced in Tor 0.3.4.8. Could be
+				// Works around a bug introduced in Tor 0.3.4.8.
-				// replaced with callback.transportDisabled() when fixed.
+				// https://trac.torproject.org/projects/tor/ticket/28027
+				// Could be replaced with callback.transportDisabled()
+				// when fixed.
 				disableNetwork();
 				updateConnectionStatus(networkManager.getNetworkStatus(),
 						batteryManager.isCharging());
@@ -685,6 +688,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			int network = settings.getInt(PREF_TOR_NETWORK,
 					PREF_TOR_NETWORK_AUTOMATIC);
 			boolean useMobile = settings.getBoolean(PREF_TOR_MOBILE, true);
+			boolean onlyWhenCharging =
+					settings.getBoolean(PREF_TOR_ONLY_WHEN_CHARGING, false);
 			boolean bridgesWork = circumventionProvider.doBridgesWork(country);
 			boolean automatic = network == PREF_TOR_NETWORK_AUTOMATIC;
 
@@ -696,8 +701,12 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			}
 
 			try {
-				if (!online) {
+				if (!online || (!charging && onlyWhenCharging)) {
-					LOG.info("Disabling network, device is offline");
+					if (!online) {
+						LOG.info("Disabling network, device is offline");
+					} else {
+						LOG.info("Disabling network, device is on battery");
+					}
 					enableNetwork(false);
 				} else if (network == PREF_TOR_NETWORK_NEVER ||
 						(!useMobile && !wifi)) {

briar-android/src/main/java/org/briarproject/briar/android/settings/SettingsFragment.java

@@ -75,6 +75,7 @@ import static org.briarproject.bramble.api.plugin.BluetoothConstants.PREF_BT_ENA
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_MOBILE;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_AUTOMATIC;
+import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_ONLY_WHEN_CHARGING;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
@@ -111,6 +112,8 @@ public class SettingsFragment extends PreferenceFragmentCompat
 	public static final String NOTIFY_SIGN_IN = "pref_key_notify_sign_in";
 	public static final String TOR_NETWORK = "pref_key_tor_network";
 	public static final String TOR_MOBILE = "pref_key_tor_mobile_data";
+	public static final String TOR_ONLY_WHEN_CHARGING =
+			"pref_key_tor_only_when_charging";
 
 	private static final Logger LOG =
 			Logger.getLogger(SettingsFragment.class.getName());
@@ -120,6 +123,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
 	private ListPreference enableBluetooth;
 	private ListPreference torNetwork;
 	private SwitchPreference torMobile;
+	private SwitchPreference torOnlyWhenCharging;
 	private SwitchPreference screenLock;
 	private ListPreference screenLockTimeout;
 	private SwitchPreference notifyPrivateMessages;
@@ -165,6 +169,8 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		enableBluetooth = (ListPreference) findPreference("pref_key_bluetooth");
 		torNetwork = (ListPreference) findPreference(TOR_NETWORK);
 		torMobile = (SwitchPreference) findPreference(TOR_MOBILE);
+		torOnlyWhenCharging =
+				(SwitchPreference) findPreference(TOR_ONLY_WHEN_CHARGING);
 		screenLock = (SwitchPreference) findPreference(PREF_SCREEN_LOCK);
 		screenLockTimeout =
 				(ListPreference) findPreference(PREF_SCREEN_LOCK_TIMEOUT);
@@ -202,6 +208,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		enableBluetooth.setOnPreferenceChangeListener(this);
 		torNetwork.setOnPreferenceChangeListener(this);
 		torMobile.setOnPreferenceChangeListener(this);
+		torOnlyWhenCharging.setOnPreferenceChangeListener(this);
 		screenLock.setOnPreferenceChangeListener(this);
 		screenLockTimeout.setOnPreferenceChangeListener(this);
 
@@ -362,6 +369,10 @@ public class SettingsFragment extends PreferenceFragmentCompat
 					torSettings.getBoolean(PREF_TOR_MOBILE, true);
 			torMobile.setChecked(torMobileSetting);
 
+			boolean torChargingSetting =
+					torSettings.getBoolean(PREF_TOR_ONLY_WHEN_CHARGING, false);
+			torOnlyWhenCharging.setChecked(torChargingSetting);
+
 			displayScreenLockSetting();
 
 			if (SDK_INT < 26) {
@@ -423,6 +434,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		enableBluetooth.setEnabled(enabled);
 		torNetwork.setEnabled(enabled);
 		torMobile.setEnabled(enabled);
+		torOnlyWhenCharging.setEnabled(enabled);
 		if (!enabled) screenLock.setEnabled(false);
 		notifyPrivateMessages.setEnabled(enabled);
 		notifyGroupMessages.setEnabled(enabled);
@@ -519,6 +531,9 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		} else if (preference == torMobile) {
 			boolean torMobileSetting = (Boolean) newValue;
 			storeTorMobileSetting(torMobileSetting);
+		} else if (preference == torOnlyWhenCharging) {
+			boolean torChargingSetting = (Boolean) newValue;
+			storeTorChargingSetting(torChargingSetting);
 		} else if (preference == screenLock) {
 			Settings s = new Settings();
 			s.putBoolean(PREF_SCREEN_LOCK, (Boolean) newValue);
@@ -585,6 +600,12 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		mergeSettings(s, TOR_NAMESPACE);
 	}
 
+	private void storeTorChargingSetting(boolean torChargingSetting) {
+		Settings s = new Settings();
+		s.putBoolean(PREF_TOR_ONLY_WHEN_CHARGING, torChargingSetting);
+		mergeSettings(s, TOR_NAMESPACE);
+	}
+
 	private void storeBluetoothSettings(boolean btSetting) {
 		Settings s = new Settings();
 		s.putBoolean(PREF_BT_ENABLE, btSetting);

briar-android/src/main/res/values/strings.xml

@@ -380,6 +380,8 @@
 	<!-- How and when Tor will connect after Automatic: E.g. Don't connect (in China) or Use Tor with bridges (in Belarus) -->
 	<string name="tor_network_setting_summary">Automatic: %1$s (in %2$s)</string>
 	<string name="tor_mobile_data_title">Use mobile data</string>
+	<string name="tor_only_when_charging_title">Connect to Internet (Tor) only when charging</string>
+	<string name="tor_only_when_charging_summary">Disables internet connection when device runs on battery</string>
 
 	<!-- Settings Security and Panic -->
 	<string name="security_settings_title">Security</string>

briar-android/src/main/res/xml/settings.xml

@@ -57,6 +57,15 @@
 			android:widgetLayout="@layout/preference_switch_compat"
 			app:iconSpaceReserved="false"/>
 
+		<SwitchPreference
+			android:defaultValue="false"
+			android:key="pref_key_tor_only_when_charging"
+			android:persistent="false"
+			android:title="@string/tor_only_when_charging_title"
+			android:summary="@string/tor_only_when_charging_summary"
+			android:widgetLayout="@layout/preference_switch_compat"
+			app:iconSpaceReserved="false"/>
+
 	</PreferenceCategory>
 
 	<PreferenceCategory