Move Connect via Bluetooth UI into DialogFragment

so it can stay active when leaving the context to enable location or permissions

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

@@ -28,6 +28,7 @@ import org.briarproject.briar.android.contact.add.remote.LinkExchangeFragment;
 import org.briarproject.briar.android.contact.add.remote.NicknameFragment;
 import org.briarproject.briar.android.contact.add.remote.PendingContactListActivity;
 import org.briarproject.briar.android.conversation.AliasDialogFragment;
+import org.briarproject.briar.android.conversation.BluetoothConnecterDialogFragment;
 import org.briarproject.briar.android.conversation.ConversationActivity;
 import org.briarproject.briar.android.conversation.ConversationSettingsDialog;
 import org.briarproject.briar.android.conversation.ImageActivity;
@@ -236,4 +237,6 @@ public interface ActivityComponent {
 
 	void inject(ConversationSettingsDialog dialog);
 
+	void inject(
+			BluetoothConnecterDialogFragment bluetoothConnecterDialogFragment);
 }

briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/AddNearbyContactPermissionManager.java

@@ -1,10 +1,6 @@
 package org.briarproject.briar.android.contact.add.nearby;
 
-import android.content.ActivityNotFoundException;
 import android.content.Context;
-import android.content.Intent;
-import android.location.LocationManager;
-import android.widget.Toast;
 
 import org.briarproject.briar.R;
 
@@ -19,11 +15,11 @@ import static android.Manifest.permission.ACCESS_FINE_LOCATION;
 import static android.Manifest.permission.CAMERA;
 import static android.content.pm.PackageManager.PERMISSION_GRANTED;
 import static android.os.Build.VERSION.SDK_INT;
-import static android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS;
-import static android.widget.Toast.LENGTH_LONG;
 import static androidx.core.app.ActivityCompat.shouldShowRequestPermissionRationale;
 import static androidx.core.content.ContextCompat.checkSelfPermission;
 import static org.briarproject.briar.android.util.UiUtils.getGoToSettingsListener;
+import static org.briarproject.briar.android.util.UiUtils.isLocationEnabled;
+import static org.briarproject.briar.android.util.UiUtils.showLocationDialog;
 
 class AddNearbyContactPermissionManager {
 
@@ -51,19 +47,6 @@ class AddNearbyContactPermissionManager {
 		locationPermission = Permission.UNKNOWN;
 	}
 
-	/**
-	 * @return true if location is enabled,
-	 * or it isn't required due to this being a SDK < 28 device.
-	 */
-	static boolean isLocationEnabled(Context ctx) {
-		if (SDK_INT >= 28) {
-			LocationManager lm = ctx.getSystemService(LocationManager.class);
-			return lm.isLocationEnabled();
-		} else {
-			return true;
-		}
-	}
-
 	static boolean areEssentialPermissionsGranted(Context ctx,
 			boolean isBluetoothSupported) {
 		int ok = PERMISSION_GRANTED;
@@ -106,7 +89,7 @@ class AddNearbyContactPermissionManager {
 		} else if (locationPermission == Permission.SHOW_RATIONALE) {
 			showRationale(R.string.permission_location_title,
 					R.string.permission_location_request_body);
-		} else if (isLocationEnabled(ctx)) {
+		} else if (locationEnabled) {
 			requestPermissions();
 		} else {
 			showLocationDialog(ctx);
@@ -135,25 +118,6 @@ class AddNearbyContactPermissionManager {
 		builder.show();
 	}
 
-	private static void showLocationDialog(Context ctx) {
-		AlertDialog.Builder builder =
-				new AlertDialog.Builder(ctx, R.style.BriarDialogTheme);
-		builder.setTitle(R.string.permission_location_setting_title);
-		builder.setMessage(R.string.permission_location_setting_body);
-		builder.setNegativeButton(R.string.cancel, null);
-		builder.setPositiveButton(R.string.permission_location_setting_button,
-				(dialog, which) -> {
-					Intent i = new Intent(ACTION_LOCATION_SOURCE_SETTINGS);
-					try {
-						ctx.startActivity(i);
-					} catch (ActivityNotFoundException e) {
-						Toast.makeText(ctx, R.string.error_start_activity,
-								LENGTH_LONG).show();
-					}
-				});
-		builder.show();
-	}
-
 	private void requestPermissions() {
 		String[] permissions;
 		if (isBluetoothSupported) {

briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/AddNearbyContactViewModel.java

@@ -82,11 +82,11 @@ import static org.briarproject.bramble.api.plugin.Plugin.State.INACTIVE;
 import static org.briarproject.bramble.api.plugin.Plugin.State.STARTING_STOPPING;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.android.contact.add.nearby.AddNearbyContactPermissionManager.areEssentialPermissionsGranted;
-import static org.briarproject.briar.android.contact.add.nearby.AddNearbyContactPermissionManager.isLocationEnabled;
 import static org.briarproject.briar.android.contact.add.nearby.AddNearbyContactViewModel.BluetoothDecision.NO_ADAPTER;
 import static org.briarproject.briar.android.contact.add.nearby.AddNearbyContactViewModel.BluetoothDecision.REFUSED;
 import static org.briarproject.briar.android.contact.add.nearby.AddNearbyContactViewModel.BluetoothDecision.UNKNOWN;
 import static org.briarproject.briar.android.util.UiUtils.handleException;
+import static org.briarproject.briar.android.util.UiUtils.isLocationEnabled;
 
 @NotNullByDefault
 class AddNearbyContactViewModel extends AndroidViewModel

briar-android/src/main/java/org/briarproject/briar/android/conversation/BluetoothConnecter.java

@@ -6,6 +6,8 @@ import android.bluetooth.BluetoothAdapter;
 import android.content.Context;
 import android.widget.Toast;
 
+import org.briarproject.bramble.api.connection.ConnectionRegistry;
+import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.plugin.BluetoothConstants;
 import org.briarproject.bramble.api.plugin.Plugin;
@@ -21,90 +23,130 @@ import java.util.logging.Logger;
 import javax.inject.Inject;
 
 import androidx.activity.result.ActivityResultLauncher;
+import androidx.annotation.Nullable;
 import androidx.annotation.StringRes;
 import androidx.annotation.UiThread;
 import androidx.appcompat.app.AlertDialog;
 
 import static android.Manifest.permission.ACCESS_FINE_LOCATION;
+import static android.os.Build.VERSION.SDK_INT;
 import static androidx.core.app.ActivityCompat.shouldShowRequestPermissionRationale;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.android.util.UiUtils.getGoToSettingsListener;
+import static org.briarproject.briar.android.util.UiUtils.isLocationEnabled;
+import static org.briarproject.briar.android.util.UiUtils.showLocationDialog;
 
 class BluetoothConnecter {
 
 	private final Logger LOG = getLogger(BluetoothConnecter.class.getName());
 
+	private enum Permission {
+		UNKNOWN, GRANTED, SHOW_RATIONALE, PERMANENTLY_DENIED
+	}
+
 	private final Application app;
 	private final Executor ioExecutor;
 	private final AndroidExecutor androidExecutor;
-
+	private final ConnectionRegistry connectionRegistry;
 	private final BluetoothAdapter bt = BluetoothAdapter.getDefaultAdapter();
 	private final Plugin bluetoothPlugin;
 
+	private Permission locationPermission = Permission.UNKNOWN;
+
 	@Inject
 	BluetoothConnecter(Application app,
 			PluginManager pluginManager,
 			@IoExecutor Executor ioExecutor,
-			AndroidExecutor androidExecutor) {
+			AndroidExecutor androidExecutor,
+			ConnectionRegistry connectionRegistry) {
 		this.app = app;
 		this.ioExecutor = ioExecutor;
 		this.androidExecutor = androidExecutor;
 		this.bluetoothPlugin = pluginManager.getPlugin(BluetoothConstants.ID);
+		this.connectionRegistry = connectionRegistry;
 	}
 
-	static void showDialog(Context ctx,
-			ActivityResultLauncher<String> permissionRequest) {
-		new AlertDialog.Builder(ctx, R.style.BriarDialogTheme)
-				.setTitle(R.string.dialog_title_connect_via_bluetooth)
-				.setMessage(R.string.dialog_message_connect_via_bluetooth)
-				.setPositiveButton(R.string.start, (dialog, which) ->
-						permissionRequest.launch(ACCESS_FINE_LOCATION))
-				.setNegativeButton(R.string.cancel, null)
-				.show();
+	boolean isConnectedViaBluetooth(ContactId contactId) {
+		return connectionRegistry.isConnected(contactId, BluetoothConstants.ID);
+	}
+
+	boolean isDiscovering() {
+		// TODO bluetoothPlugin.isDiscovering()
+		return false;
+	}
+
+	/**
+	 * Call this when the using activity or fragment starts,
+	 * because permissions might have changed while it was stopped.
+	 */
+	void resetPermissions() {
+		locationPermission = Permission.UNKNOWN;
 	}
 
 	@UiThread
-	void onLocationPermissionResult(Activity activity, boolean result,
-			ActivityResultLauncher<Integer> bluetoothDiscoverableRequest) {
-		if (result) {
-			if (isBluetoothSupported()) {
-				bluetoothDiscoverableRequest.launch(120);
-			} else {
-				showToast(R.string.toast_connect_via_bluetooth_error);
-			}
+	void onLocationPermissionResult(Activity activity,
+			@Nullable Boolean result) {
+		if (result != null && result) {
+			locationPermission = Permission.GRANTED;
 		} else if (shouldShowRequestPermissionRationale(activity,
 				ACCESS_FINE_LOCATION)) {
-			showToast(R.string.permission_location_denied_body);
+			locationPermission = Permission.SHOW_RATIONALE;
 		} else {
-			showRationale(activity);
+			locationPermission = Permission.PERMANENTLY_DENIED;
 		}
 	}
 
-	private boolean isBluetoothSupported() {
-		return bt != null && bluetoothPlugin != null;
+	boolean isBluetoothNotSupported() {
+		// When this class is instantiated before we are logged in
+		// (like when returning to a killed activity), bluetoothPlugin will be
+		// null and we consider bluetooth not supported.
+		return bt == null || bluetoothPlugin == null;
 	}
 
-	private void showRationale(Context ctx) {
+	boolean areRequirementsFulfilled(Context ctx,
+			ActivityResultLauncher<String> permissionRequest) {
+		boolean permissionGranted =
+				SDK_INT < 23 || locationPermission == Permission.GRANTED;
+		boolean locationEnabled = isLocationEnabled(ctx);
+		if (permissionGranted && locationEnabled) return true;
+
+		if (locationPermission == Permission.PERMANENTLY_DENIED) {
+			showDenialDialog(ctx);
+		} else if (locationPermission == Permission.SHOW_RATIONALE) {
+			showRationale(ctx, permissionRequest);
+		} else if (!locationEnabled) {
+			showLocationDialog(ctx);
+		}
+		return false;
+	}
+
+	private void showDenialDialog(Context ctx) {
 		new AlertDialog.Builder(ctx, R.style.BriarDialogTheme)
 				.setTitle(R.string.permission_location_title)
-				.setMessage(R.string.permission_location_request_body)
+				.setMessage(R.string.permission_location_denied_body)
 				.setPositiveButton(R.string.ok, getGoToSettingsListener(ctx))
 				.setNegativeButton(R.string.cancel, null)
 				.show();
 	}
 
-	@UiThread
-	void onBluetoothDiscoverable(boolean result, ContactItem contact) {
-		if (result) {
-			connect(contact);
-		} else {
-			showToast(R.string.toast_connect_via_bluetooth_not_discoverable);
-		}
+	private void showRationale(Context ctx,
+			ActivityResultLauncher<String> permissionRequest) {
+		new AlertDialog.Builder(ctx, R.style.BriarDialogTheme)
+				.setTitle(R.string.permission_location_title)
+				.setMessage(R.string.permission_location_request_body)
+				.setPositiveButton(R.string.ok, (dialog, which) ->
+						permissionRequest.launch(ACCESS_FINE_LOCATION))
+				.show();
 	}
 
-	private void connect(ContactItem contact) {
+	@UiThread
+	void onBluetoothDiscoverable(ContactItem contact) {
+		connect(contact.getContact().getId());
+	}
+
+	private void connect(ContactId contactId) {
 		// TODO
 		//  * enable bluetooth connections setting, if not enabled
 		//  * wait for plugin to become active

briar-android/src/main/java/org/briarproject/briar/android/conversation/BluetoothConnecterDialogFragment.java

@@ -0,0 +1,143 @@
+package org.briarproject.briar.android.conversation;
+
+import android.app.Activity;
+import android.app.Dialog;
+import android.content.Context;
+import android.os.Bundle;
+import android.view.View;
+import android.widget.Button;
+import android.widget.Toast;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.activity.BaseActivity;
+import org.briarproject.briar.android.contact.ContactItem;
+import org.briarproject.briar.android.util.RequestBluetoothDiscoverable;
+
+import javax.inject.Inject;
+
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.activity.result.contract.ActivityResultContracts.RequestPermission;
+import androidx.annotation.Nullable;
+import androidx.annotation.StringRes;
+import androidx.appcompat.app.AlertDialog;
+import androidx.fragment.app.DialogFragment;
+import androidx.lifecycle.ViewModelProvider;
+
+import static android.Manifest.permission.ACCESS_FINE_LOCATION;
+import static android.content.DialogInterface.BUTTON_POSITIVE;
+import static android.widget.Toast.LENGTH_LONG;
+import static java.util.Objects.requireNonNull;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+public class BluetoothConnecterDialogFragment extends DialogFragment {
+
+	final static String TAG = BluetoothConnecterDialogFragment.class.getName();
+
+	@Inject
+	ViewModelProvider.Factory viewModelFactory;
+
+	private ConversationViewModel viewModel;
+	private BluetoothConnecter bluetoothConnecter;
+
+	private final ActivityResultLauncher<Integer> bluetoothDiscoverableRequest =
+			registerForActivityResult(new RequestBluetoothDiscoverable(),
+					this::onBluetoothDiscoverable);
+	private final ActivityResultLauncher<String> permissionRequest =
+			registerForActivityResult(new RequestPermission(),
+					this::onPermissionRequestResult);
+
+	@Override
+	public void onAttach(Context ctx) {
+		super.onAttach(ctx);
+		((BaseActivity) requireActivity()).getActivityComponent().inject(this);
+		viewModel = new ViewModelProvider(requireActivity(), viewModelFactory)
+				.get(ConversationViewModel.class);
+		bluetoothConnecter = viewModel.getBluetoothConnecter();
+	}
+
+	@Override
+	public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
+		Context ctx = requireContext();
+		return new AlertDialog.Builder(ctx, R.style.BriarDialogTheme)
+				.setTitle(R.string.dialog_title_connect_via_bluetooth)
+				.setMessage(R.string.dialog_message_connect_via_bluetooth)
+				// actual listener gets set in onResume()
+				.setPositiveButton(R.string.start, null)
+				.setNegativeButton(R.string.cancel, null)
+				.setCancelable(false) // keep it open until dismissed
+				.create();
+	}
+
+	@Override
+	public void onStart() {
+		super.onStart();
+		if (bluetoothConnecter.isBluetoothNotSupported()) {
+			showToast(R.string.toast_connect_via_bluetooth_error);
+			dismiss();
+			return;
+		}
+		// MenuItem only gets enabled after contactItem has loaded
+		ContactItem contact =
+				requireNonNull(viewModel.getContactItem().getValue());
+		ContactId contactId = contact.getContact().getId();
+		if (bluetoothConnecter.isConnectedViaBluetooth(contactId)) {
+			showToast(R.string.toast_connect_via_bluetooth_success);
+			dismiss();
+			return;
+		}
+		if (bluetoothConnecter.isDiscovering()) {
+			// TODO showToast(R.string.toast_connect_via_bluetooth_discovering);
+			dismiss();
+			return;
+		}
+		bluetoothConnecter.resetPermissions();
+	}
+
+	@Override
+	public void onResume() {
+		super.onResume();
+		// Set the click listener for the START button here
+		// to prevent it from automatically dismissing the dialog.
+		// The dialog is shown in onStart(), so we set the listener here later.
+		AlertDialog dialog = (AlertDialog) getDialog();
+		Button positiveButton = (Button) dialog.getButton(BUTTON_POSITIVE);
+		positiveButton.setOnClickListener(this::onStartClicked);
+	}
+
+	private void onStartClicked(View v) {
+		// The dialog starts a permission request which comes back as true
+		// if the permission is already granted. So it is a generic entry point.
+		permissionRequest.launch(ACCESS_FINE_LOCATION);
+	}
+
+	private void onPermissionRequestResult(@Nullable Boolean result) {
+		Activity a = requireActivity();
+		// update permission result in BluetoothConnecter
+		bluetoothConnecter.onLocationPermissionResult(a, result);
+		// if requirements are fulfilled, request Bluetooth discoverability
+		if (bluetoothConnecter.areRequirementsFulfilled(a, permissionRequest)) {
+			bluetoothDiscoverableRequest.launch(120); // for 2min
+		}
+	}
+
+	private void onBluetoothDiscoverable(@Nullable Boolean result) {
+		if (result != null && result) {
+			// MenuItem only gets enabled after contactItem has loaded
+			ContactItem contact =
+					requireNonNull(viewModel.getContactItem().getValue());
+			bluetoothConnecter.onBluetoothDiscoverable(contact);
+			dismiss();
+		} else {
+			showToast(R.string.toast_connect_via_bluetooth_not_discoverable);
+		}
+	}
+
+	private void showToast(@StringRes int stringRes) {
+		Toast.makeText(requireContext(), stringRes, LENGTH_LONG).show();
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationActivity.java

@@ -47,7 +47,6 @@ import org.briarproject.briar.android.activity.BriarActivity;
 import org.briarproject.briar.android.attachment.AttachmentItem;
 import org.briarproject.briar.android.attachment.AttachmentRetriever;
 import org.briarproject.briar.android.blog.BlogActivity;
-import org.briarproject.briar.android.contact.ContactItem;
 import org.briarproject.briar.android.conversation.ConversationVisitor.AttachmentCache;
 import org.briarproject.briar.android.conversation.ConversationVisitor.TextCache;
 import org.briarproject.briar.android.forum.ForumActivity;
@@ -92,8 +91,6 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
-import androidx.activity.result.ActivityResultLauncher;
-import androidx.activity.result.contract.ActivityResultContracts.RequestPermission;
 import androidx.annotation.Nullable;
 import androidx.annotation.UiThread;
 import androidx.appcompat.app.AlertDialog;
@@ -102,6 +99,7 @@ import androidx.appcompat.widget.Toolbar;
 import androidx.core.app.ActivityCompat;
 import androidx.core.app.ActivityOptionsCompat;
 import androidx.core.content.ContextCompat;
+import androidx.fragment.app.FragmentManager;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.Observer;
 import androidx.lifecycle.ViewModelProvider;
@@ -214,21 +212,6 @@ public class ConversationActivity extends BriarActivity
 
 	private volatile ContactId contactId;
 
-	private final ActivityResultLauncher<Integer> bluetoothDiscoverableRequest =
-			registerForActivityResult(new RequestBluetoothDiscoverable(), r -> {
-				// MenuItem only gets enabled after contactItem has loaded
-				ContactItem contact =
-						requireNonNull(viewModel.getContactItem().getValue());
-				BluetoothConnecter bc = viewModel.getBluetoothConnecter();
-				bc.onBluetoothDiscoverable(r, contact);
-			});
-	private final ActivityResultLauncher<String> permissionRequest =
-			registerForActivityResult(new RequestPermission(), result -> {
-				BluetoothConnecter bc = viewModel.getBluetoothConnecter();
-				bc.onLocationPermissionResult(this, result,
-						bluetoothDiscoverableRequest);
-			});
-
 	@Override
 	public void onCreate(@Nullable Bundle state) {
 		if (SDK_INT >= 21) {
@@ -424,7 +407,9 @@ public class ConversationActivity extends BriarActivity
 			onAutoDeleteTimerNoticeClicked();
 			return true;
 		} else if (itemId == R.id.action_connect_via_bluetooth) {
-			BluetoothConnecter.showDialog(this, permissionRequest);
+			FragmentManager fm = getSupportFragmentManager();
+			new BluetoothConnecterDialogFragment().show(fm,
+					BluetoothConnecterDialogFragment.TAG);
 			return true;
 		} else if (itemId == R.id.action_delete_all_messages) {
 			askToDeleteAllMessages();

briar-android/src/main/java/org/briarproject/briar/android/conversation/RequestBluetoothDiscoverable.java

@@ -1,30 +0,0 @@
-package org.briarproject.briar.android.conversation;
-
-import android.content.Context;
-import android.content.Intent;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import androidx.activity.result.contract.ActivityResultContract;
-import androidx.annotation.Nullable;
-
-import static android.app.Activity.RESULT_CANCELED;
-import static android.bluetooth.BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE;
-import static android.bluetooth.BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION;
-
-@NotNullByDefault
-class RequestBluetoothDiscoverable
-		extends ActivityResultContract<Integer, Boolean> {
-
-	@Override
-	public Intent createIntent(Context context, Integer duration) {
-		Intent i = new Intent(ACTION_REQUEST_DISCOVERABLE);
-		i.putExtra(EXTRA_DISCOVERABLE_DURATION, duration);
-		return i;
-	}
-
-	@Override
-	public Boolean parseResult(int resultCode, @Nullable Intent intent) {
-		return resultCode != RESULT_CANCELED;
-	}
-}

briar-android/src/main/java/org/briarproject/briar/android/util/UiUtils.java

@@ -3,11 +3,13 @@ package org.briarproject.briar.android.util;
 import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.app.KeyguardManager;
+import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.DialogInterface.OnClickListener;
 import android.content.Intent;
 import android.content.res.Resources;
 import android.graphics.drawable.Drawable;
+import android.location.LocationManager;
 import android.net.Uri;
 import android.os.PowerManager;
 import android.text.Spannable;
@@ -72,6 +74,7 @@ import static android.content.Intent.EXTRA_MIME_TYPES;
 import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
 import static android.os.Build.MANUFACTURER;
 import static android.os.Build.VERSION.SDK_INT;
+import static android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS;
 import static android.provider.Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS;
 import static android.text.format.DateUtils.DAY_IN_MILLIS;
 import static android.text.format.DateUtils.FORMAT_ABBREV_ALL;
@@ -331,6 +334,19 @@ public class UiUtils {
 		return i;
 	}
 
+	/**
+	 * @return true if location is enabled,
+	 * or it isn't required due to this being a SDK < 28 device.
+	 */
+	public static boolean isLocationEnabled(Context ctx) {
+		if (SDK_INT >= 28) {
+			LocationManager lm = ctx.getSystemService(LocationManager.class);
+			return lm.isLocationEnabled();
+		} else {
+			return true;
+		}
+	}
+
 	public static boolean isSamsung7() {
 		return (SDK_INT == 24 || SDK_INT == 25) &&
 				MANUFACTURER.equalsIgnoreCase("Samsung");
@@ -474,6 +490,25 @@ public class UiUtils {
 		return isoCode;
 	}
 
+	public static void showLocationDialog(Context ctx) {
+		AlertDialog.Builder builder =
+				new AlertDialog.Builder(ctx, R.style.BriarDialogTheme);
+		builder.setTitle(R.string.permission_location_setting_title);
+		builder.setMessage(R.string.permission_location_setting_body);
+		builder.setNegativeButton(R.string.cancel, null);
+		builder.setPositiveButton(R.string.permission_location_setting_button,
+				(dialog, which) -> {
+					Intent i = new Intent(ACTION_LOCATION_SOURCE_SETTINGS);
+					try {
+						ctx.startActivity(i);
+					} catch (ActivityNotFoundException e) {
+						Toast.makeText(ctx, R.string.error_start_activity,
+								LENGTH_LONG).show();
+					}
+				});
+		builder.show();
+	}
+
 	public static Drawable getDialogIcon(Context ctx, @DrawableRes int resId) {
 		Drawable icon =
 				VectorDrawableCompat.create(ctx.getResources(), resId, null);