Screen Lock: Lock after customizable inactivity timeout

briar-android/src/main/java/org/briarproject/briar/android/BriarService.java

@@ -26,6 +26,7 @@ import org.briarproject.briar.R;
 import org.briarproject.briar.android.logout.HideUiActivity;
 import org.briarproject.briar.android.navdrawer.NavDrawerActivity;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
+import org.briarproject.briar.api.android.LockManager;
 
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -54,6 +55,7 @@ import static org.briarproject.briar.api.android.AndroidNotificationManager.FAIL
 import static org.briarproject.briar.api.android.AndroidNotificationManager.FAILURE_NOTIFICATION_ID;
 import static org.briarproject.briar.api.android.AndroidNotificationManager.ONGOING_CHANNEL_ID;
 import static org.briarproject.briar.api.android.AndroidNotificationManager.ONGOING_NOTIFICATION_ID;
+import static org.briarproject.briar.api.android.LockManager.ACTION_LOCK;
 
 public class BriarService extends Service {
 
@@ -77,6 +79,8 @@ public class BriarService extends Service {
 	AndroidNotificationManager notificationManager;
 	@Inject
 	AccountManager accountManager;
+	@Inject
+	LockManager lockManager;
 
 	// Fields that are accessed from background threads must be volatile
 	@Inject
@@ -189,6 +193,9 @@ public class BriarService extends Service {
 
 	@Override
 	public int onStartCommand(Intent intent, int flags, int startId) {
+		if (ACTION_LOCK.equals(intent.getAction())) {
+			lockManager.setLocked(true);
+		}
 		return START_NOT_STICKY; // Don't restart automatically if killed
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/account/LockManagerImpl.java

 package org.briarproject.briar.android.account;
 
+import android.app.AlarmManager;
 import android.app.Application;
+import android.app.PendingIntent;
 import android.arch.lifecycle.LiveData;
 import android.arch.lifecycle.MutableLiveData;
 import android.content.Context;
+import android.content.Intent;
 import android.support.annotation.UiThread;
 
 import org.briarproject.bramble.api.db.DatabaseExecutor;
@@ -16,6 +19,8 @@ import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.SettingsManager;
 import org.briarproject.bramble.api.settings.event.SettingsUpdatedEvent;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.BriarService;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.android.LockManager;
 
@@ -25,9 +30,15 @@ import java.util.logging.Logger;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
+import static android.app.AlarmManager.ELAPSED_REALTIME;
+import static android.app.PendingIntent.getService;
+import static android.content.Context.ALARM_SERVICE;
+import static android.os.SystemClock.elapsedRealtime;
+import static java.util.concurrent.TimeUnit.MINUTES;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.android.settings.SettingsFragment.PREF_SCREEN_LOCK;
+import static org.briarproject.briar.android.settings.SettingsFragment.PREF_SCREEN_LOCK_TIMEOUT;
 import static org.briarproject.briar.android.settings.SettingsFragment.SETTINGS_NAMESPACE;
 import static org.briarproject.briar.android.util.UiUtils.hasScreenLock;
 
@@ -44,9 +55,14 @@ public class LockManagerImpl implements LockManager, Service, EventListener {
 	private final AndroidNotificationManager notificationManager;
 	@DatabaseExecutor
 	private final Executor dbExecutor;
+	private final AlarmManager alarmManager;
+	private final PendingIntent lockIntent;
+	private final int timeoutNever, timeoutDefault;
 
 	private volatile boolean locked = false;
 	private volatile boolean lockableSetting = false;
+	private volatile int timeoutMinutes;
+	private int activitiesRunning = 0;
 	private final MutableLiveData<Boolean> lockable = new MutableLiveData<>();
 
 	@Inject
@@ -57,6 +73,16 @@ public class LockManagerImpl implements LockManager, Service, EventListener {
 		this.settingsManager = settingsManager;
 		this.notificationManager = notificationManager;
 		this.dbExecutor = dbExecutor;
+		this.alarmManager =
+				(AlarmManager) appContext.getSystemService(ALARM_SERVICE);
+		Intent i =
+				new Intent(ACTION_LOCK, null, appContext, BriarService.class);
+		this.lockIntent = getService(appContext, 0, i, 0);
+		this.timeoutNever = Integer.valueOf(
+				appContext.getString(R.string.pref_lock_timeout_value_never));
+		this.timeoutDefault = Integer.valueOf(
+				appContext.getString(R.string.pref_lock_timeout_value_default));
+		this.timeoutMinutes = timeoutNever;
 
 		// setting this in the constructor makes #getValue() @NonNull
 		this.lockable.setValue(false);
@@ -72,6 +98,26 @@ public class LockManagerImpl implements LockManager, Service, EventListener {
 	public void stopService() {
 	}
 
+	@UiThread
+	@Override
+	public void onActivityStart() {
+		activitiesRunning++;
+		alarmManager.cancel(lockIntent);
+	}
+
+	@UiThread
+	@Override
+	public void onActivityStop() {
+		activitiesRunning--;
+		if (activitiesRunning == 0 && !locked &&
+				timeoutMinutes != timeoutNever && lockable.getValue()) {
+			alarmManager.cancel(lockIntent);
+			long triggerAt =
+					elapsedRealtime() + MINUTES.toMillis(timeoutMinutes);
+			alarmManager.set(ELAPSED_REALTIME, triggerAt, lockIntent);
+		}
+	}
+
 	@Override
 	public LiveData<Boolean> isLockable() {
 		return lockable;
@@ -118,9 +164,13 @@ public class LockManagerImpl implements LockManager, Service, EventListener {
 			try {
 				Settings settings =
 						settingsManager.getSettings(SETTINGS_NAMESPACE);
+				// is the app lockable?
 				lockableSetting = settings.getBoolean(PREF_SCREEN_LOCK, false);
 				boolean newValue = hasScreenLock(appContext) && lockableSetting;
 				lockable.postValue(newValue);
+				// what is the timeout in minutes?
+				timeoutMinutes = settings.getInt(PREF_SCREEN_LOCK_TIMEOUT,
+						timeoutDefault);
 			} catch (DbException e) {
 				logException(LOG, WARNING, e);
 				lockableSetting = false;

briar-android/src/main/java/org/briarproject/briar/android/activity/BriarActivity.java

@@ -53,6 +53,12 @@ public abstract class BriarActivity extends BaseActivity {
 	@Inject
 	protected LockManager lockManager;
 
+	@Override
+	public void onStart() {
+		super.onStart();
+		lockManager.onActivityStart();
+	}
+
 	@Override
 	protected void onActivityResult(int request, int result, Intent data) {
 		super.onActivityResult(request, result, data);
@@ -97,6 +103,12 @@ public abstract class BriarActivity extends BaseActivity {
 		}
 	}
 
+	@Override
+	protected void onStop() {
+		super.onStop();
+		lockManager.onActivityStop();
+	}
+
 	public void setSceneTransitionAnimation() {
 		if (SDK_INT < 21) return;
 		// workaround for #1007

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

@@ -15,6 +15,7 @@ import android.support.v4.content.ContextCompat;
 import android.support.v4.text.TextUtilsCompat;
 import android.support.v7.preference.ListPreference;
 import android.support.v7.preference.Preference;
+import android.support.v7.preference.Preference.OnPreferenceChangeListener;
 import android.support.v7.preference.PreferenceFragmentCompat;
 import android.support.v7.preference.PreferenceGroup;
 import android.view.LayoutInflater;
@@ -105,13 +106,15 @@ import static org.briarproject.briar.api.android.AndroidNotificationManager.PREF
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class SettingsFragment extends PreferenceFragmentCompat
-		implements EventListener, Preference.OnPreferenceChangeListener {
+		implements EventListener, OnPreferenceChangeListener {
 
 	public static final String SETTINGS_NAMESPACE = "android-ui";
 	public static final String BT_NAMESPACE = BluetoothConstants.ID.getString();
 	public static final String TOR_NAMESPACE = TorConstants.ID.getString();
 	public static final String LANGUAGE = "pref_key_language";
 	public static final String PREF_SCREEN_LOCK = "pref_key_lock";
+	public static final String PREF_SCREEN_LOCK_TIMEOUT =
+			"pref_key_lock_timeout";
 	public static final String NOTIFY_SIGN_IN = "pref_key_notify_sign_in";
 	public static final String TOR_LOCATION = "pref_key_tor_location";
 
@@ -124,6 +127,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
 	private ListPreference torNetwork;
 	private SwitchPreference torBlocked;
 	private SwitchPreference screenLock;
+	private ListPreference screenLockTimeout;
 	private SwitchPreference notifyPrivateMessages;
 	private SwitchPreference notifyGroupMessages;
 	private SwitchPreference notifyForumPosts;
@@ -166,6 +170,8 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		SwitchPreference notifySignIn =
 				(SwitchPreference) findPreference(NOTIFY_SIGN_IN);
 		screenLock = (SwitchPreference) findPreference(PREF_SCREEN_LOCK);
+		screenLockTimeout =
+				(ListPreference) findPreference(PREF_SCREEN_LOCK_TIMEOUT);
 		notifyPrivateMessages = (SwitchPreference) findPreference(
 				"pref_key_notify_private_messages");
 		notifyGroupMessages = (SwitchPreference) findPreference(
@@ -203,6 +209,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		torNetwork.setOnPreferenceChangeListener(this);
 		torBlocked.setOnPreferenceChangeListener(this);
 		screenLock.setOnPreferenceChangeListener(this);
+		screenLockTimeout.setOnPreferenceChangeListener(this);
 		if (SDK_INT >= 21) {
 			notifyLockscreen.setVisible(true);
 			notifyLockscreen.setOnPreferenceChangeListener(this);
@@ -224,6 +231,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
 			theme.setVisible(FEATURE_FLAG_DARK_THEME);
 			notifySignIn.setVisible(FEATURE_FLAG_SIGN_IN_REMINDER);
 			screenLock.setVisible(FEATURE_FLAG_PIN_LOCK);
+			screenLockTimeout.setVisible(FEATURE_FLAG_PIN_LOCK);
 
 			findPreference("pref_key_explode").setVisible(false);
 			findPreference("pref_key_test_data").setVisible(false);
@@ -419,6 +427,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
 		// - pref_key_notify_sign_in
 		// preferences partly needed here, because they have their own logic
 		// - pref_key_lock (screenLock -> displayScreenLockSetting())
+		// - pref_key_lock_timeout (screenLockTimeout)
 		enableBluetooth.setEnabled(enabled);
 		torNetwork.setEnabled(enabled);
 		torBlocked.setEnabled(enabled);
@@ -435,6 +444,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
 	private void displayScreenLockSetting() {
 		if (SDK_INT < 21) {
 			screenLock.setVisible(false);
+			screenLockTimeout.setVisible(false);
 		} else {
 			if (getActivity() != null && hasScreenLock(getActivity())) {
 				screenLock.setEnabled(true);
@@ -446,6 +456,11 @@ public class SettingsFragment extends PreferenceFragmentCompat
 				screenLock.setChecked(false);
 				screenLock.setSummary(R.string.pref_lock_disabled_summary);
 			}
+			// timeout depends on screenLock and gets disabled automatically
+			int timeout = settings.getInt(PREF_SCREEN_LOCK_TIMEOUT,
+					Integer.valueOf(getString(
+							R.string.pref_lock_timeout_value_default)));
+			screenLockTimeout.setValue(String.valueOf(timeout));
 		}
 	}
 
@@ -508,6 +523,11 @@ public class SettingsFragment extends PreferenceFragmentCompat
 			Settings s = new Settings();
 			s.putBoolean(PREF_SCREEN_LOCK, (Boolean) newValue);
 			storeSettings(s);
+		} else if (preference == screenLockTimeout) {
+			Settings s = new Settings();
+			s.putInt(PREF_SCREEN_LOCK_TIMEOUT,
+					Integer.valueOf((String) newValue));
+			storeSettings(s);
 		} else if (preference == notifyPrivateMessages) {
 			Settings s = new Settings();
 			s.putBoolean(PREF_NOTIFY_PRIVATE, (Boolean) newValue);

briar-android/src/main/java/org/briarproject/briar/api/android/LockManager.java

 package org.briarproject.briar.api.android;
 
+import android.app.Activity;
 import android.arch.lifecycle.LiveData;
 import android.support.annotation.UiThread;
 
 public interface LockManager {
 
+	String ACTION_LOCK = "lock";
+
+	/**
+	 * Stops the inactivity timer when the user interacts with the app.
+	 * Should typically be called by {@link Activity#onStart()}
+	 */
+	@UiThread
+	void onActivityStart();
+
+	/**
+	 * Starts the inactivity timer which will lock the app.
+	 * Should typically be called by {@link Activity#onStop()}
+	 */
+	@UiThread
+	void onActivityStop();
+
 	/**
 	 * Returns an observable LiveData to indicate whether the app can be locked.
 	 */

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

@@ -67,4 +67,23 @@
 		<item>@string/pref_theme_auto_value</item>
 		<item>@string/pref_theme_system_value</item>
 	</string-array>
+
+	<string-array name="pref_key_lock_timeout_entries">
+		<item>@string/pref_lock_timeout_never</item>
+		<item>@string/pref_lock_timeout_1</item>
+		<item>@string/pref_lock_timeout_5</item>
+		<item>@string/pref_lock_timeout_15</item>
+		<item>@string/pref_lock_timeout_30</item>
+		<item>@string/pref_lock_timeout_60</item>
+	</string-array>
+	<string name="pref_lock_timeout_value_default">5</string>
+	<string name="pref_lock_timeout_value_never">-1</string>
+	<string-array name="pref_key_lock_timeout_values">
+		<item>@string/pref_lock_timeout_value_never</item>
+		<item>1</item>
+		<item>5</item>
+		<item>15</item>
+		<item>30</item>
+		<item>60</item>
+	</string-array>
 </resources>

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

@@ -360,6 +360,15 @@
 	<string name="pref_lock_title">Screen Lock</string>
 	<string name="pref_lock_summary">Use the device\'s screen lock to protect Briar while signed in</string>
 	<string name="pref_lock_disabled_summary">Set up a screen lock for your device to protect Briar while signed in</string>
+	<string name="pref_lock_timeout_title">Screen Lock Inactivity Timeout</string>
+	<string name="pref_lock_timeout_summary">When not using Briar, automatically lock it %s</string>
+	<string name="pref_lock_timeout_never">never</string>
+	<string name="pref_lock_timeout_1">after 1 Minute</string>
+	<string name="pref_lock_timeout_5">after 5 Minutes</string>
+	<string name="pref_lock_timeout_15">after 15 Minutes</string>
+	<string name="pref_lock_timeout_30">after 30 Minutes</string>
+	<string name="pref_lock_timeout_60">after 1 Hour</string>
+
 	<string name="change_password">Change password</string>
 	<string name="current_password">Current password</string>
 	<string name="choose_new_password">New password</string>

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

@@ -60,8 +60,17 @@
 			android:key="pref_key_lock"
 			android:persistent="false"
 			android:summary="@string/pref_lock_summary"
-			android:title="@string/pref_lock_title"
-			android:enabled="false"/>
+			android:title="@string/pref_lock_title"/>
+
+		<ListPreference
+			android:defaultValue="@string/pref_lock_timeout_value_default"
+			android:dependency="pref_key_lock"
+			android:entries="@array/pref_key_lock_timeout_entries"
+			android:entryValues="@array/pref_key_lock_timeout_values"
+			android:key="pref_key_lock_timeout"
+			android:persistent="false"
+			android:summary="@string/pref_lock_timeout_summary"
+			android:title="@string/pref_lock_timeout_title"/>
 
 		<Preference
 			android:key="pref_key_change_password"