Factor out permission related code from KeyAgreementActivity to AddNearbyContactPermissionManager

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

@@ -0,0 +1,154 @@
+package org.briarproject.briar.android.contact.add.nearby;
+
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.activity.BaseActivity;
+
+import androidx.annotation.StringRes;
+import androidx.appcompat.app.AlertDialog;
+import androidx.core.app.ActivityCompat;
+
+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 org.briarproject.briar.android.activity.RequestCodes.REQUEST_PERMISSION_CAMERA_LOCATION;
+import static org.briarproject.briar.android.util.UiUtils.getGoToSettingsListener;
+
+class AddNearbyContactPermissionManager {
+
+	private enum Permission {
+		UNKNOWN, GRANTED, SHOW_RATIONALE, PERMANENTLY_DENIED
+	}
+
+	private Permission cameraPermission = Permission.UNKNOWN;
+	private Permission locationPermission = Permission.UNKNOWN;
+
+	private final BaseActivity ctx;
+	private final boolean isBluetoothSupported;
+
+	AddNearbyContactPermissionManager(BaseActivity ctx,
+			boolean isBluetoothSupported) {
+		this.ctx = ctx;
+		this.isBluetoothSupported = isBluetoothSupported;
+	}
+
+	void resetPermissions() {
+		cameraPermission = Permission.UNKNOWN;
+		locationPermission = Permission.UNKNOWN;
+	}
+
+	boolean areEssentialPermissionsGranted() {
+		return cameraPermission == Permission.GRANTED &&
+				(SDK_INT < 23 || locationPermission == Permission.GRANTED ||
+						!isBluetoothSupported);
+	}
+
+	boolean checkPermissions() {
+		if (areEssentialPermissionsGranted()) return true;
+		// If an essential permission has been permanently denied, ask the
+		// user to change the setting
+		if (cameraPermission == Permission.PERMANENTLY_DENIED) {
+			showDenialDialog(R.string.permission_camera_title,
+					R.string.permission_camera_denied_body);
+			return false;
+		}
+		if (isBluetoothSupported &&
+				locationPermission == Permission.PERMANENTLY_DENIED) {
+			showDenialDialog(R.string.permission_location_title,
+					R.string.permission_location_denied_body);
+			return false;
+		}
+		// Should we show the rationale for one or both permissions?
+		if (cameraPermission == Permission.SHOW_RATIONALE &&
+				locationPermission == Permission.SHOW_RATIONALE) {
+			showRationale(R.string.permission_camera_location_title,
+					R.string.permission_camera_location_request_body);
+		} else if (cameraPermission == Permission.SHOW_RATIONALE) {
+			showRationale(R.string.permission_camera_title,
+					R.string.permission_camera_request_body);
+		} else if (locationPermission == Permission.SHOW_RATIONALE) {
+			showRationale(R.string.permission_location_title,
+					R.string.permission_location_request_body);
+		} else {
+			requestPermissions();
+		}
+		return false;
+	}
+
+	private void showDenialDialog(@StringRes int title, @StringRes int body) {
+		AlertDialog.Builder builder =
+				new AlertDialog.Builder(ctx, R.style.BriarDialogTheme);
+		builder.setTitle(title);
+		builder.setMessage(body);
+		builder.setPositiveButton(R.string.ok, getGoToSettingsListener(ctx));
+		builder.setNegativeButton(R.string.cancel,
+				(dialog, which) -> ctx.supportFinishAfterTransition());
+		builder.show();
+	}
+
+	private void showRationale(@StringRes int title, @StringRes int body) {
+		AlertDialog.Builder builder =
+				new AlertDialog.Builder(ctx, R.style.BriarDialogTheme);
+		builder.setTitle(title);
+		builder.setMessage(body);
+		builder.setNeutralButton(R.string.continue_button,
+				(dialog, which) -> requestPermissions());
+		builder.show();
+	}
+
+	private void requestPermissions() {
+		String[] permissions;
+		if (isBluetoothSupported) {
+			permissions = new String[] {CAMERA, ACCESS_FINE_LOCATION};
+		} else {
+			permissions = new String[] {CAMERA};
+		}
+		ActivityCompat.requestPermissions(ctx, permissions,
+				REQUEST_PERMISSION_CAMERA_LOCATION);
+	}
+
+	void onRequestPermissionsResult(int requestCode, String[] permissions,
+			int[] grantResults, Runnable onPermissionsGranted) {
+		if (requestCode != REQUEST_PERMISSION_CAMERA_LOCATION)
+			throw new AssertionError();
+		if (gotPermission(CAMERA, permissions, grantResults)) {
+			cameraPermission = Permission.GRANTED;
+		} else if (shouldShowRationale(CAMERA)) {
+			cameraPermission = Permission.SHOW_RATIONALE;
+		} else {
+			cameraPermission = Permission.PERMANENTLY_DENIED;
+		}
+		if (isBluetoothSupported) {
+			if (gotPermission(ACCESS_FINE_LOCATION, permissions,
+					grantResults)) {
+				locationPermission = Permission.GRANTED;
+			} else if (shouldShowRationale(ACCESS_FINE_LOCATION)) {
+				locationPermission = Permission.SHOW_RATIONALE;
+			} else {
+				locationPermission = Permission.PERMANENTLY_DENIED;
+			}
+		}
+		// If a permission dialog has been shown, showing the QR code fragment
+		// on this call path would cause a crash due to
+		// https://code.google.com/p/android/issues/detail?id=190966.
+		// In that case the isResumed flag prevents the fragment from being
+		// shown here, and showQrCodeFragmentIfAllowed() will be called again
+		// from onPostResume().
+		if (checkPermissions()) onPermissionsGranted.run();
+	}
+
+	private boolean gotPermission(String permission, String[] permissions,
+			int[] grantResults) {
+		for (int i = 0; i < permissions.length; i++) {
+			if (permission.equals(permissions[i]))
+				return grantResults[i] == PERMISSION_GRANTED;
+		}
+		return false;
+	}
+
+	private boolean shouldShowRationale(String permission) {
+		return ActivityCompat
+				.shouldShowRequestPermissionRationale(ctx, permission);
+	}
+
+}

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

@@ -21,38 +21,25 @@ import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
-import androidx.annotation.StringRes;
 import androidx.annotation.UiThread;
-import androidx.appcompat.app.AlertDialog.Builder;
 import androidx.appcompat.widget.Toolbar;
-import androidx.core.app.ActivityCompat;
 import androidx.fragment.app.FragmentManager;
 import androidx.lifecycle.ViewModelProvider;
 
-import static android.Manifest.permission.ACCESS_FINE_LOCATION;
-import static android.Manifest.permission.CAMERA;
 import static android.bluetooth.BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE;
 import static android.bluetooth.BluetoothAdapter.ACTION_SCAN_MODE_CHANGED;
-import static android.content.pm.PackageManager.PERMISSION_GRANTED;
-import static android.os.Build.VERSION.SDK_INT;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_BLUETOOTH_DISCOVERABLE;
-import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_PERMISSION_CAMERA_LOCATION;
 import static org.briarproject.briar.android.contact.add.nearby.ContactExchangeViewModel.BluetoothDecision.ACCEPTED;
 import static org.briarproject.briar.android.contact.add.nearby.ContactExchangeViewModel.BluetoothDecision.REFUSED;
 import static org.briarproject.briar.android.contact.add.nearby.ContactExchangeViewModel.BluetoothDecision.UNKNOWN;
-import static org.briarproject.briar.android.util.UiUtils.getGoToSettingsListener;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public abstract class KeyAgreementActivity extends BriarActivity
 		implements BaseFragmentListener {
 
-	private enum Permission {
-		UNKNOWN, GRANTED, SHOW_RATIONALE, PERMANENTLY_DENIED
-	}
-
 	private static final Logger LOG =
 			getLogger(KeyAgreementActivity.class.getName());
 
@@ -60,6 +47,7 @@ public abstract class KeyAgreementActivity extends BriarActivity
 	ViewModelProvider.Factory viewModelFactory;
 
 	protected ContactExchangeViewModel viewModel;
+	private AddNearbyContactPermissionManager permissionManager;
 
 	/**
 	 * Set to true in onPostResume() and false in onPause(). This prevents the
@@ -68,9 +56,6 @@ public abstract class KeyAgreementActivity extends BriarActivity
 	 * https://issuetracker.google.com/issues/37067655.
 	 */
 	private boolean isResumed = false;
-
-	private Permission cameraPermission = Permission.UNKNOWN;
-	private Permission locationPermission = Permission.UNKNOWN;
 	private BroadcastReceiver bluetoothReceiver = null;
 
 	@Override
@@ -78,6 +63,8 @@ public abstract class KeyAgreementActivity extends BriarActivity
 		component.inject(this);
 		viewModel = new ViewModelProvider(this, viewModelFactory)
 				.get(ContactExchangeViewModel.class);
+		permissionManager = new AddNearbyContactPermissionManager(this,
+				viewModel.isBluetoothSupported());
 	}
 
 	@Override
@@ -94,7 +81,9 @@ public abstract class KeyAgreementActivity extends BriarActivity
 		bluetoothReceiver = new BluetoothStateReceiver();
 		registerReceiver(bluetoothReceiver, filter);
 		viewModel.getWasContinueClicked().observe(this, clicked -> {
-			if (clicked && checkPermissions()) showQrCodeFragmentIfAllowed();
+			if (clicked && permissionManager.checkPermissions()) {
+				showQrCodeFragmentIfAllowed();
+			}
 		});
 		viewModel.getTransportStateChanged().observeEvent(this,
 				t -> showQrCodeFragmentIfAllowed());
@@ -107,8 +96,7 @@ public abstract class KeyAgreementActivity extends BriarActivity
 	public void onStart() {
 		super.onStart();
 		// Permissions may have been granted manually while we were stopped
-		cameraPermission = Permission.UNKNOWN;
+		permissionManager.resetPermissions();
-		locationPermission = Permission.UNKNOWN;
 	}
 
 	@Override
@@ -126,11 +114,6 @@ public abstract class KeyAgreementActivity extends BriarActivity
 		isResumed = false;
 	}
 
-	@Override
-	protected void onStop() {
-		super.onStop();
-	}
-
 	@Override
 	public void onDestroy() {
 		super.onDestroy();
@@ -146,31 +129,29 @@ public abstract class KeyAgreementActivity extends BriarActivity
 		return super.onOptionsItemSelected(item);
 	}
 
-	@SuppressWarnings("StatementWithEmptyBody")
+	@Override
-	private void showQrCodeFragmentIfAllowed() {
+	public void onActivityResult(int request, int result,
-		boolean continueClicked = // never set to null
+			@Nullable Intent data) {
-				requireNonNull(viewModel.getWasContinueClicked().getValue());
+		if (request == REQUEST_BLUETOOTH_DISCOVERABLE) {
-		if (isResumed && continueClicked && areEssentialPermissionsGranted()) {
+			if (result == RESULT_CANCELED) {
-			if (viewModel.isWifiReady() && viewModel.isBluetoothReady()) {
+				LOG.info("Bluetooth discoverability was refused");
-				LOG.info("Wifi and Bluetooth are ready");
+				viewModel.bluetoothDecision = REFUSED;
-				viewModel.startAddingContact();
 			} else {
-				viewModel.enableWifiIfWeShould();
+				LOG.info("Bluetooth discoverability was accepted");
-				if (viewModel.bluetoothDecision == UNKNOWN) {
+				viewModel.bluetoothDecision = ACCEPTED;
-					requestBluetoothDiscoverable();
-				} else if (viewModel.bluetoothDecision == REFUSED) {
-					// Ask again when the user clicks "continue"
-				} else {
-					viewModel.enableBluetoothIfWeShould();
-				}
 			}
-		}
+			showQrCodeFragmentIfAllowed();
+		} else super.onActivityResult(request, result, data);
 	}
 
-	private boolean areEssentialPermissionsGranted() {
+	@Override
-		return cameraPermission == Permission.GRANTED &&
+	@UiThread
-				(SDK_INT < 23 || locationPermission == Permission.GRANTED ||
+	public void onRequestPermissionsResult(int requestCode,
-						!viewModel.isBluetoothSupported());
+			String[] permissions, int[] grantResults) {
+		super.onRequestPermissionsResult(requestCode, permissions,
+				grantResults);
+		permissionManager.onRequestPermissionsResult(requestCode, permissions,
+				grantResults, this::showQrCodeFragmentIfAllowed);
 	}
 
 	private void requestBluetoothDiscoverable() {
@@ -190,19 +171,27 @@ public abstract class KeyAgreementActivity extends BriarActivity
 		}
 	}
 
-	@Override
+	@SuppressWarnings("StatementWithEmptyBody")
-	public void onActivityResult(int request, int result,
+	private void showQrCodeFragmentIfAllowed() {
-			@Nullable Intent data) {
+		boolean continueClicked = // never set to null
-		if (request == REQUEST_BLUETOOTH_DISCOVERABLE) {
+				requireNonNull(viewModel.getWasContinueClicked().getValue());
-			if (result == RESULT_CANCELED) {
+		boolean permissionsGranted =
-				LOG.info("Bluetooth discoverability was refused");
+				permissionManager.areEssentialPermissionsGranted();
-				viewModel.bluetoothDecision = REFUSED;
+		if (isResumed && continueClicked && permissionsGranted) {
+			if (viewModel.isWifiReady() && viewModel.isBluetoothReady()) {
+				LOG.info("Wifi and Bluetooth are ready");
+				viewModel.startAddingContact();
 			} else {
-				LOG.info("Bluetooth discoverability was accepted");
+				viewModel.enableWifiIfWeShould();
-				viewModel.bluetoothDecision = ACCEPTED;
+				if (viewModel.bluetoothDecision == UNKNOWN) {
+					requestBluetoothDiscoverable();
+				} else if (viewModel.bluetoothDecision == REFUSED) {
+					// Ask again when the user clicks "continue"
+				} else {
+					viewModel.enableBluetoothIfWeShould();
+				}
 			}
-			showQrCodeFragmentIfAllowed();
+		}
-		} else super.onActivityResult(request, result, data);
 	}
 
 	private void showQrCodeFragment() {
@@ -217,118 +206,7 @@ public abstract class KeyAgreementActivity extends BriarActivity
 		}
 	}
 
-	private boolean checkPermissions() {
-		if (areEssentialPermissionsGranted()) return true;
-		// If an essential permission has been permanently denied, ask the
-		// user to change the setting
-		if (cameraPermission == Permission.PERMANENTLY_DENIED) {
-			showDenialDialog(R.string.permission_camera_title,
-					R.string.permission_camera_denied_body);
-			return false;
-		}
-		if (viewModel.isBluetoothSupported() &&
-				locationPermission == Permission.PERMANENTLY_DENIED) {
-			showDenialDialog(R.string.permission_location_title,
-					R.string.permission_location_denied_body);
-			return false;
-		}
-		// Should we show the rationale for one or both permissions?
-		if (cameraPermission == Permission.SHOW_RATIONALE &&
-				locationPermission == Permission.SHOW_RATIONALE) {
-			showRationale(R.string.permission_camera_location_title,
-					R.string.permission_camera_location_request_body);
-		} else if (cameraPermission == Permission.SHOW_RATIONALE) {
-			showRationale(R.string.permission_camera_title,
-					R.string.permission_camera_request_body);
-		} else if (locationPermission == Permission.SHOW_RATIONALE) {
-			showRationale(R.string.permission_location_title,
-					R.string.permission_location_request_body);
-		} else {
-			requestPermissions();
-		}
-		return false;
-	}
-
-	private void showDenialDialog(@StringRes int title, @StringRes int body) {
-		Builder builder = new Builder(this, R.style.BriarDialogTheme);
-		builder.setTitle(title);
-		builder.setMessage(body);
-		builder.setPositiveButton(R.string.ok, getGoToSettingsListener(this));
-		builder.setNegativeButton(R.string.cancel,
-				(dialog, which) -> supportFinishAfterTransition());
-		builder.show();
-	}
-
-	private void showRationale(@StringRes int title, @StringRes int body) {
-		Builder builder = new Builder(this, R.style.BriarDialogTheme);
-		builder.setTitle(title);
-		builder.setMessage(body);
-		builder.setNeutralButton(R.string.continue_button,
-				(dialog, which) -> requestPermissions());
-		builder.show();
-	}
-
-	private void requestPermissions() {
-		String[] permissions;
-		if (viewModel.isBluetoothSupported()) {
-			permissions = new String[] {CAMERA, ACCESS_FINE_LOCATION};
-		} else {
-			permissions = new String[] {CAMERA};
-		}
-		ActivityCompat.requestPermissions(this, permissions,
-				REQUEST_PERMISSION_CAMERA_LOCATION);
-	}
-
-	@Override
-	@UiThread
-	public void onRequestPermissionsResult(int requestCode,
-			String[] permissions, int[] grantResults) {
-		super.onRequestPermissionsResult(requestCode, permissions,
-				grantResults);
-		if (requestCode != REQUEST_PERMISSION_CAMERA_LOCATION)
-			throw new AssertionError();
-		if (gotPermission(CAMERA, permissions, grantResults)) {
-			cameraPermission = Permission.GRANTED;
-		} else if (shouldShowRationale(CAMERA)) {
-			cameraPermission = Permission.SHOW_RATIONALE;
-		} else {
-			cameraPermission = Permission.PERMANENTLY_DENIED;
-		}
-		if (viewModel.isBluetoothSupported()) {
-			if (gotPermission(ACCESS_FINE_LOCATION, permissions,
-					grantResults)) {
-				locationPermission = Permission.GRANTED;
-			} else if (shouldShowRationale(ACCESS_FINE_LOCATION)) {
-				locationPermission = Permission.SHOW_RATIONALE;
-			} else {
-				locationPermission = Permission.PERMANENTLY_DENIED;
-			}
-		}
-		// If a permission dialog has been shown, showing the QR code fragment
-		// on this call path would cause a crash due to
-		// https://code.google.com/p/android/issues/detail?id=190966.
-		// In that case the isResumed flag prevents the fragment from being
-		// shown here, and showQrCodeFragmentIfAllowed() will be called again
-		// from onPostResume().
-		if (checkPermissions()) showQrCodeFragmentIfAllowed();
-	}
-
-	private boolean gotPermission(String permission, String[] permissions,
-			int[] grantResults) {
-		for (int i = 0; i < permissions.length; i++) {
-			if (permission.equals(permissions[i]))
-				return grantResults[i] == PERMISSION_GRANTED;
-		}
-		return false;
-	}
-
-	private boolean shouldShowRationale(String permission) {
-		return ActivityCompat.shouldShowRequestPermissionRationale(this,
-				permission);
-	}
-
 	private class BluetoothStateReceiver extends BroadcastReceiver {
-
 		@Override
 		public void onReceive(Context context, Intent intent) {
 			LOG.info("Bluetooth scan mode changed");