Remember that app entered doze mode and inform user when returning

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

@@ -3,12 +3,16 @@ package org.briarproject.briar.android;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.app.Service;
+import android.content.BroadcastReceiver;
 import android.content.ComponentName;
+import android.content.Context;
 import android.content.Intent;
+import android.content.IntentFilter;
 import android.content.ServiceConnection;
 import android.os.Binder;
-import android.os.Build;
 import android.os.IBinder;
+import android.os.PowerManager;
+import android.support.annotation.Nullable;
 import android.support.v4.app.NotificationCompat;
 import android.support.v4.content.ContextCompat;
 
@@ -28,12 +32,15 @@ import javax.inject.Inject;
 import static android.app.PendingIntent.FLAG_UPDATE_CURRENT;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
 import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
+import static android.os.Build.VERSION.SDK_INT;
+import static android.os.PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED;
 import static android.support.v4.app.NotificationCompat.CATEGORY_SERVICE;
 import static android.support.v4.app.NotificationCompat.PRIORITY_MIN;
 import static android.support.v4.app.NotificationCompat.VISIBILITY_SECRET;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.ALREADY_RUNNING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.SUCCESS;
+import static org.briarproject.briar.android.util.UiUtils.needsDozeWhitelisting;
 
 public class BriarService extends Service {
 
@@ -45,6 +52,9 @@ public class BriarService extends Service {
 
 	private final AtomicBoolean created = new AtomicBoolean(false);
 	private final Binder binder = new BriarBinder();
+	@Nullable
+	private BriarBroadcastReceiver receiver = null;
+	private boolean hasDozed = false;
 
 	@Inject
 	protected DatabaseConfig databaseConfig;
@@ -84,7 +94,7 @@ public class BriarService extends Service {
 		Intent i = new Intent(this, NavDrawerActivity.class);
 		i.setFlags(FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_CLEAR_TOP);
 		b.setContentIntent(PendingIntent.getActivity(this, 0, i, 0));
-		if (Build.VERSION.SDK_INT >= 21) {
+		if (SDK_INT >= 21) {
 			b.setCategory(CATEGORY_SERVICE);
 			b.setVisibility(VISIBILITY_SECRET);
 		}
@@ -109,6 +119,7 @@ public class BriarService extends Service {
 				}
 			}
 		}.start();
+		registerBroadcastReceiver();
 	}
 
 	private void showStartupFailureNotification(StartResult result) {
@@ -153,6 +164,7 @@ public class BriarService extends Service {
 	public void onDestroy() {
 		super.onDestroy();
 		LOG.info("Destroyed");
+		if (receiver != null) unregisterReceiver(receiver);
 		stopForeground(true);
 		// Stop the services in a background thread
 		new Thread() {
@@ -170,6 +182,21 @@ public class BriarService extends Service {
 		// FIXME: Work out what to do about it
 	}
 
+	private void registerBroadcastReceiver() {
+		if (SDK_INT < 23) return;
+		IntentFilter filter = new IntentFilter(ACTION_DEVICE_IDLE_MODE_CHANGED);
+		if (receiver == null) receiver = new BriarBroadcastReceiver();
+		registerReceiver(receiver, filter);
+	}
+
+	public boolean hasDozed() {
+		return hasDozed;
+	}
+
+	public void resetDozeFlag() {
+		hasDozed = false;
+	}
+
 	/**
 	 * Waits for all services to start before returning.
 	 */
@@ -225,4 +252,15 @@ public class BriarService extends Service {
 			return binder;
 		}
 	}
+
+	public class BriarBroadcastReceiver extends BroadcastReceiver {
+		@Override
+		public void onReceive(Context context, Intent intent) {
+			if (SDK_INT < 23 || !needsDozeWhitelisting(getApplicationContext()))
+				return;
+			PowerManager pm = (PowerManager) getSystemService(POWER_SERVICE);
+			if (pm.isDeviceIdleMode()) hasDozed = true;
+		}
+	}
+
 }

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

@@ -4,15 +4,18 @@ import android.annotation.SuppressLint;
 import android.content.Intent;
 import android.os.Build;
 import android.support.v7.app.ActionBar;
+import android.support.v7.app.AlertDialog;
 import android.support.v7.widget.Toolbar;
 import android.transition.Slide;
 import android.transition.Transition;
 import android.view.Gravity;
 import android.view.Window;
+import android.widget.CheckBox;
 
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.controller.BriarController;
 import org.briarproject.briar.android.controller.DbController;
+import org.briarproject.briar.android.controller.handler.UiResultHandler;
 import org.briarproject.briar.android.login.PasswordActivity;
 import org.briarproject.briar.android.panic.ExitActivity;
 
@@ -25,7 +28,9 @@ import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TASK;
 import static android.content.Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS;
 import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
 import static android.content.Intent.FLAG_ACTIVITY_NO_ANIMATION;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_DOZE_WHITELISTING;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_PASSWORD;
+import static org.briarproject.briar.android.util.UiUtils.getDozeWhitelistingIntent;
 
 @SuppressLint("Registered")
 public abstract class BriarActivity extends BaseActivity {
@@ -59,6 +64,13 @@ public abstract class BriarActivity extends BaseActivity {
 		if (!briarController.hasEncryptionKey() && !isFinishing()) {
 			Intent i = new Intent(this, PasswordActivity.class);
 			startActivityForResult(i, REQUEST_PASSWORD);
+		} else {
+			briarController.hasDozed(new UiResultHandler<Boolean>(this) {
+				@Override
+				public void onResultUi(Boolean result) {
+					if (result) showDozeDialog();
+				}
+			});
 		}
 	}
 
@@ -97,6 +109,29 @@ public abstract class BriarActivity extends BaseActivity {
 		return toolbar;
 	}
 
+	private void showDozeDialog() {
+		AlertDialog.Builder b =
+				new AlertDialog.Builder(this, R.style.BriarDialogTheme);
+		b.setMessage(getString(R.string.warning_dozed,
+				getString(R.string.app_name)));
+		b.setView(R.layout.checkbox);
+		b.setPositiveButton(R.string.fix,
+				(dialog, which) -> {
+					Intent i = getDozeWhitelistingIntent(BriarActivity.this);
+					startActivityForResult(i, REQUEST_DOZE_WHITELISTING);
+					dialog.dismiss();
+				});
+		b.setNegativeButton(R.string.cancel,
+				(dialog, which) -> dialog.dismiss());
+		b.setOnDismissListener(dialog -> {
+			CheckBox checkBox = (CheckBox) ((AlertDialog) dialog)
+					.findViewById(R.id.checkbox);
+			if (checkBox.isChecked())
+				briarController.doNotNotifyWhenDozed();
+		});
+		b.show();
+	}
+
 	protected void signOut(boolean removeFromRecentApps) {
 		if (briarController.hasEncryptionKey()) {
 			// Don't use UiResultHandler because we want the result even if

briar-android/src/main/java/org/briarproject/briar/android/controller/BriarController.java

@@ -8,5 +8,13 @@ public interface BriarController extends ActivityLifecycleController {
 
 	boolean hasEncryptionKey();
 
+	/**
+	 * Returns true via the handler when the app has dozed
+	 * without being white-listed.
+	 */
+	void hasDozed(ResultHandler<Boolean> handler);
+
+	void doNotNotifyWhenDozed();
+
 	void signOut(ResultHandler<Void> eventHandler);
 }

briar-android/src/main/java/org/briarproject/briar/android/controller/BriarControllerImpl.java

@@ -6,30 +6,48 @@ import android.os.IBinder;
 import android.support.annotation.CallSuper;
 
 import org.briarproject.bramble.api.db.DatabaseConfig;
+import org.briarproject.bramble.api.db.DatabaseExecutor;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.settings.Settings;
+import org.briarproject.bramble.api.settings.SettingsManager;
 import org.briarproject.briar.android.BriarService;
 import org.briarproject.briar.android.BriarService.BriarServiceConnection;
 import org.briarproject.briar.android.controller.handler.ResultHandler;
 
+import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import static java.util.logging.Level.WARNING;
+import static org.briarproject.briar.android.settings.SettingsFragment.SETTINGS_NAMESPACE;
+import static org.briarproject.briar.android.util.UiUtils.needsDozeWhitelisting;
+
 public class BriarControllerImpl implements BriarController {
 
 	private static final Logger LOG =
 			Logger.getLogger(BriarControllerImpl.class.getName());
 
+	private static final String HAS_DOZED_ASK_AGAIN = "hasDozedAskAgain";
+
 	private final BriarServiceConnection serviceConnection;
 	private final DatabaseConfig databaseConfig;
+	@DatabaseExecutor
+	private final Executor databaseExecutor;
+	private final SettingsManager settingsManager;
 	private final Activity activity;
 
 	private boolean bound = false;
 
 	@Inject
 	BriarControllerImpl(BriarServiceConnection serviceConnection,
-			DatabaseConfig databaseConfig, Activity activity) {
+			DatabaseConfig databaseConfig,
+			@DatabaseExecutor Executor databaseExecutor,
+			SettingsManager settingsManager, Activity activity) {
 		this.serviceConnection = serviceConnection;
 		this.databaseConfig = databaseConfig;
+		this.databaseExecutor = databaseExecutor;
+		this.settingsManager = settingsManager;
 		this.activity = activity;
 	}
 
@@ -65,6 +83,50 @@ public class BriarControllerImpl implements BriarController {
 		return databaseConfig.getEncryptionKey() != null;
 	}
 
+	@Override
+	public void hasDozed(ResultHandler<Boolean> handler) {
+		// check this first, to hit the DbThread only when really necessary
+		if (!needsDozeWhitelisting(activity)) {
+			handler.onResult(false);
+			return;
+		}
+		databaseExecutor.execute(() -> {
+			try {
+				Settings settings =
+						settingsManager.getSettings(SETTINGS_NAMESPACE);
+				boolean ask = settings.getBoolean(HAS_DOZED_ASK_AGAIN, true);
+				if (!ask) {
+					handler.onResult(false);
+					return;
+				}
+				IBinder binder = serviceConnection.waitForBinder();
+				BriarService service =
+						((BriarService.BriarBinder) binder).getService();
+				handler.onResult(service.hasDozed());
+				service.resetDozeFlag();
+			} catch (InterruptedException e) {
+				LOG.warning("Interrupted while waiting for service");
+			} catch (DbException e) {
+				if (LOG.isLoggable(WARNING))
+					LOG.log(WARNING, e.toString(), e);
+			}
+		});
+	}
+
+	@Override
+	public void doNotNotifyWhenDozed() {
+		databaseExecutor.execute(() -> {
+			try {
+				Settings settings = new Settings();
+				settings.putBoolean(HAS_DOZED_ASK_AGAIN, false);
+				settingsManager.mergeSettings(settings, SETTINGS_NAMESPACE);
+			} catch (DbException e) {
+				if (LOG.isLoggable(WARNING))
+					LOG.log(WARNING, e.toString(), e);
+			}
+		});
+	}
+
 	@Override
 	public void signOut(ResultHandler<Void> eventHandler) {
 		new Thread() {

briar-android/src/main/java/org/briarproject/briar/android/navdrawer/NavDrawerControllerImpl.java

@@ -158,42 +158,37 @@ public class NavDrawerControllerImpl extends DbControllerImpl
 	}
 
 	@Override
-	public void askDozeWhitelisting(final Context ctx,
-			final ResultHandler<Boolean> handler) {
+	public void askDozeWhitelisting(Context ctx,
+			ResultHandler<Boolean> handler) {
+		// check this first, to hit the DbThread only when really necessary
 		if (!needsDozeWhitelisting(ctx)) {
 			handler.onResult(false);
 			return;
 		}
-		runOnDbThread(new Runnable() {
-			@Override
-			public void run() {
-				try {
-					Settings settings =
-							settingsManager.getSettings(SETTINGS_NAMESPACE);
-					boolean ask = settings.getBoolean(DOZE_ASK_AGAIN, true);
-					handler.onResult(ask);
-				} catch (DbException e) {
-					if (LOG.isLoggable(WARNING))
-						LOG.log(WARNING, e.toString(), e);
-					handler.onResult(true);
-				}
+		runOnDbThread(() -> {
+			try {
+				Settings settings =
+						settingsManager.getSettings(SETTINGS_NAMESPACE);
+				boolean ask = settings.getBoolean(DOZE_ASK_AGAIN, true);
+				handler.onResult(ask);
+			} catch (DbException e) {
+				if (LOG.isLoggable(WARNING))
+					LOG.log(WARNING, e.toString(), e);
+				handler.onResult(true);
 			}
 		});
 	}
 
 	@Override
 	public void doNotAskAgainForDozeWhiteListing() {
-		runOnDbThread(new Runnable() {
-			@Override
-			public void run() {
-				try {
-					Settings settings = new Settings();
-					settings.putBoolean(DOZE_ASK_AGAIN, false);
-					settingsManager.mergeSettings(settings, SETTINGS_NAMESPACE);
-				} catch (DbException e) {
-					if (LOG.isLoggable(WARNING))
-						LOG.log(WARNING, e.toString(), e);
-				}
+		runOnDbThread(() -> {
+			try {
+				Settings settings = new Settings();
+				settings.putBoolean(DOZE_ASK_AGAIN, false);
+				settingsManager.mergeSettings(settings, SETTINGS_NAMESPACE);
+			} catch (DbException e) {
+				if (LOG.isLoggable(WARNING))
+					LOG.log(WARNING, e.toString(), e);
 			}
 		});
 	}

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

@@ -95,6 +95,8 @@
 	<string name="ellipsis">…</string>
 	<string name="text_too_long">The entered text is too long</string>
 	<string name="show_onboarding">Show Help Dialog</string>
+	<string name="warning_dozed">%s was unable to run in the background</string>
+	<string name="fix">Fix</string>
 
 	<!-- Contacts and Private Conversations-->
 	<string name="no_contacts">It seems that you are new here and have no contacts yet.\n\nTap the + icon at the top and follow the instructions to add some friends to your list.\n\nPlease remember: You can only add new contacts face-to-face to prevent anyone from impersonating you or reading your messages in the future.</string>
@@ -391,7 +393,7 @@
 	<string name="screen_filter_title">Screen overlay detected</string>
 	<string name="screen_filter_body">Another app is drawing on top of Briar. To protect your security, Briar will not respond to touches when another app is drawing on top.\n\nTry turning off the following apps when using Briar:\n\n%1$s</string>
 
-	<!-- Permission Requests and Doze Mode -->
+	<!-- Permission Requests -->
 	<string name="permission_camera_title">Camera permission</string>
 	<string name="permission_camera_request_body">To scan the QR code, Briar needs access to the camera.</string>
 	<string name="permission_camera_denied_body">You have denied access to the camera, but adding contacts requires using the camera.\n\nPlease consider granting access.</string>