WIP make part of keyAgreement public, so it can be used for shard return

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

@@ -87,6 +87,7 @@ import org.briarproject.briar.android.socialbackup.DistributedBackupActivity;
 import org.briarproject.briar.android.socialbackup.ExistingBackupFragment;
 import org.briarproject.briar.android.socialbackup.OwnerRecoveryModeExplainerFragment;
 import org.briarproject.briar.android.socialbackup.RecoverActivity;
+import org.briarproject.briar.android.socialbackup.ShardQrCodeFragment;
 import org.briarproject.briar.android.socialbackup.ShardsSentFragment;
 import org.briarproject.briar.android.socialbackup.ThresholdSelectorFragment;
 import org.briarproject.briar.android.socialbackup.creation.CreateBackupModule;
@@ -258,6 +259,8 @@ public interface ActivityComponent {
 
 	void inject(ThresholdSelectorFragment thresholdSelectorFragment);
 
+	void inject(ShardQrCodeFragment shardQrCodeFragment);
+
 	void inject(DistributedBackupActivity distributedBackupActivity);
 
 	void inject(RecoverActivity recoverActivity);

briar-android/src/main/java/org/briarproject/briar/android/keyagreement/CameraException.java

@@ -2,7 +2,7 @@ package org.briarproject.briar.android.keyagreement;
 
 import java.io.IOException;
 
-class CameraException extends IOException {
+public class CameraException extends IOException {
 
 	CameraException(String message) {
 		super(message);

briar-android/src/main/java/org/briarproject/briar/android/keyagreement/QrCodeDecoder.java

@@ -30,7 +30,7 @@ import static java.util.logging.Level.WARNING;
 @SuppressWarnings("deprecation")
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-class QrCodeDecoder implements PreviewConsumer, PreviewCallback {
+public class QrCodeDecoder implements PreviewConsumer, PreviewCallback {
 
 	private static final Logger LOG =
 			Logger.getLogger(QrCodeDecoder.class.getName());
@@ -41,7 +41,7 @@ class QrCodeDecoder implements PreviewConsumer, PreviewCallback {
 	private Camera camera = null;
 	private int cameraIndex = 0;
 
-	QrCodeDecoder(ResultCallback callback) {
+	public QrCodeDecoder(ResultCallback callback) {
 		this.callback = callback;
 	}
 
@@ -142,7 +142,7 @@ class QrCodeDecoder implements PreviewConsumer, PreviewCallback {
 	}
 
 	@NotNullByDefault
-	interface ResultCallback {
+	public interface ResultCallback {
 
 		void handleResult(Result result);
 	}

briar-android/src/main/java/org/briarproject/briar/android/keyagreement/QrCodeUtils.java

@@ -21,13 +21,13 @@ import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
 @NotNullByDefault
-class QrCodeUtils {
+public class QrCodeUtils {
 
 	private static final Logger LOG =
 			Logger.getLogger(QrCodeUtils.class.getName());
 
 	@Nullable
-	static Bitmap createQrCode(DisplayMetrics dm, String input) {
+	public static Bitmap createQrCode(DisplayMetrics dm, String input) {
 		int smallestDimen = Math.min(dm.widthPixels, dm.heightPixels);
 		try {
 			// Generate QR code

briar-android/src/main/java/org/briarproject/briar/android/socialbackup/RecoverActivity.java

@@ -3,14 +3,59 @@ package org.briarproject.briar.android.socialbackup;
 import android.os.Bundle;
 import android.widget.Toast;
 
+import org.briarproject.bramble.api.keyagreement.KeyAgreementResult;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BaseActivity;
 import org.briarproject.briar.android.fragment.BaseFragment;
 
+import javax.annotation.Nullable;
+
+import androidx.annotation.UiThread;
+import androidx.core.app.ActivityCompat;
+
+import static android.Manifest.permission.CAMERA;
+import static android.content.pm.PackageManager.PERMISSION_GRANTED;
+import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_PERMISSION_CAMERA_LOCATION;
+
 public class RecoverActivity extends BaseActivity implements
 		BaseFragment.BaseFragmentListener, ExplainerDismissedListener,
-		ScanQrButtonListener {
+		ScanQrButtonListener, ShardQrCodeFragment.ShardQrCodeEventListener {
+
+	@Override
+	public void keyAgreementFailed() {
+
+	}
+
+	@Nullable
+	@Override
+	public String keyAgreementWaiting() {
+		return null;
+	}
+
+	@Nullable
+	@Override
+	public String keyAgreementStarted() {
+		return null;
+	}
+
+	@Override
+	public void keyAgreementAborted(boolean remoteAborted) {
+
+	}
+
+	@Nullable
+	@Override
+	public String keyAgreementFinished(KeyAgreementResult result) {
+		return null;
+	}
+
+	private enum Permission {
+		UNKNOWN, GRANTED, SHOW_RATIONALE, PERMANENTLY_DENIED
+	}
+
+	private Permission cameraPermission = Permission.UNKNOWN;
+
 
 	private int numRecovered;
 
@@ -47,11 +92,79 @@ public class RecoverActivity extends BaseActivity implements
 
 	@Override
 	public void scanQrButtonClicked() {
-		// TODO
+		if (checkPermissions()) showQrCodeFragment();
-		Toast.makeText(this,
+	}
-				"coming soon...",
+
-				Toast.LENGTH_SHORT).show();
+
-		finish();
+	private void showQrCodeFragment() {
+		ShardQrCodeFragment f = ShardQrCodeFragment.newInstance();
+		showNextFragment(f);
+	}
+
+	private void requestPermissions() {
+		String[] permissions = new String[] {CAMERA};
+		ActivityCompat.requestPermissions(this, permissions,
+				REQUEST_PERMISSION_CAMERA_LOCATION);
+	}
+
+	@Override
+	@UiThread
+	public void onRequestPermissionsResult(int requestCode,
+			String[] permissions, int[] 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 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()) showQrCodeFragment();
+	}
+
+	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 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) {
+			Toast.makeText(this,
+					"camera permission is denied",
+					Toast.LENGTH_SHORT).show();
+//			showDenialDialog(R.string.permission_camera_title,
+//					R.string.permission_camera_denied_body);
+			return false;
+		}
+		if (cameraPermission == Permission.SHOW_RATIONALE) {
+//			showRationale(R.string.permission_camera_title,
+//					R.string.permission_camera_request_body);
+			Toast.makeText(this,
+					"camera permission - show rationale",
+					Toast.LENGTH_SHORT).show();
+		} else {
+			requestPermissions();
+		}
+		return false;
 	}
 
 	@Override
@@ -59,4 +172,8 @@ public class RecoverActivity extends BaseActivity implements
 	public void runOnDbThread(Runnable runnable) {
 		throw new RuntimeException("Don't use this deprecated method here.");
 	}
+
+	private boolean areEssentialPermissionsGranted() {
+		return cameraPermission == Permission.GRANTED;
+	}
 }

briar-android/src/main/java/org/briarproject/briar/android/socialbackup/ShardQrCodeFragment.java

@@ -0,0 +1,381 @@
+package org.briarproject.briar.android.socialbackup;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.os.Bundle;
+import android.util.DisplayMetrics;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.LinearLayout;
+import android.widget.TextView;
+import android.widget.Toast;
+
+import com.google.zxing.Result;
+
+import org.briarproject.bramble.api.UnsupportedVersionException;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.keyagreement.KeyAgreementResult;
+import org.briarproject.bramble.api.keyagreement.KeyAgreementTask;
+import org.briarproject.bramble.api.keyagreement.Payload;
+import org.briarproject.bramble.api.keyagreement.PayloadEncoder;
+import org.briarproject.bramble.api.keyagreement.PayloadParser;
+import org.briarproject.bramble.api.keyagreement.event.KeyAgreementAbortedEvent;
+import org.briarproject.bramble.api.keyagreement.event.KeyAgreementFailedEvent;
+import org.briarproject.bramble.api.keyagreement.event.KeyAgreementFinishedEvent;
+import org.briarproject.bramble.api.keyagreement.event.KeyAgreementListeningEvent;
+import org.briarproject.bramble.api.keyagreement.event.KeyAgreementStartedEvent;
+import org.briarproject.bramble.api.keyagreement.event.KeyAgreementWaitingEvent;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.activity.ActivityComponent;
+import org.briarproject.briar.android.fragment.BaseEventFragment;
+import org.briarproject.briar.android.keyagreement.CameraException;
+import org.briarproject.briar.android.keyagreement.CameraView;
+import org.briarproject.briar.android.keyagreement.ContactExchangeErrorFragment;
+import org.briarproject.briar.android.keyagreement.QrCodeDecoder;
+import org.briarproject.briar.android.keyagreement.QrCodeUtils;
+import org.briarproject.briar.android.view.QrCodeView;
+
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+import javax.inject.Inject;
+import javax.inject.Provider;
+
+import androidx.annotation.UiThread;
+
+import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_NOSENSOR;
+import static android.view.View.INVISIBLE;
+import static android.view.View.VISIBLE;
+import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
+import static android.widget.LinearLayout.HORIZONTAL;
+import static android.widget.Toast.LENGTH_LONG;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.util.LogUtils.logException;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+public class ShardQrCodeFragment extends BaseEventFragment
+		implements QrCodeDecoder.ResultCallback, QrCodeView.FullscreenListener {
+
+	static final String TAG = org.briarproject.briar.android.keyagreement.KeyAgreementFragment.class.getName();
+
+	private static final Logger LOG = Logger.getLogger(TAG);
+	@SuppressWarnings("CharsetObjectCanBeUsed") // Requires minSdkVersion >= 19
+	private static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
+
+	@Inject
+	Provider<KeyAgreementTask> keyAgreementTaskProvider;
+	@Inject
+	PayloadEncoder payloadEncoder;
+	@Inject
+	PayloadParser payloadParser;
+	@Inject
+	@IoExecutor
+	Executor ioExecutor;
+	@Inject
+	EventBus eventBus;
+
+	private CameraView cameraView;
+	private LinearLayout cameraOverlay;
+	private View statusView;
+	private QrCodeView qrCodeView;
+	private TextView status;
+
+	private boolean gotRemotePayload;
+	private volatile boolean gotLocalPayload;
+	private KeyAgreementTask task;
+	private ShardQrCodeEventListener
+			listener;
+
+	public static ShardQrCodeFragment newInstance() {
+		Bundle args = new Bundle();
+		ShardQrCodeFragment
+				fragment = new ShardQrCodeFragment();
+		fragment.setArguments(args);
+		return fragment;
+	}
+
+	@Override
+	public void onAttach(Context context) {
+		super.onAttach(context);
+		listener = (ShardQrCodeEventListener) context;
+	}
+
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+	}
+
+	@Override
+	public String getUniqueTag() {
+		return TAG;
+	}
+
+	@Nullable
+	@Override
+	public View onCreateView(LayoutInflater inflater,
+			@Nullable ViewGroup container,
+			@Nullable Bundle savedInstanceState) {
+		return inflater.inflate(R.layout.fragment_keyagreement_qr, container,
+				false);
+	}
+
+	@Override
+	public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
+		super.onViewCreated(view, savedInstanceState);
+		cameraView = view.findViewById(R.id.camera_view);
+		cameraOverlay = view.findViewById(R.id.camera_overlay);
+		statusView = view.findViewById(R.id.status_container);
+		status = view.findViewById(R.id.connect_status);
+		qrCodeView = view.findViewById(R.id.qr_code_view);
+		qrCodeView.setFullscreenListener(this);
+	}
+
+	@Override
+	public void onActivityCreated(@Nullable Bundle savedInstanceState) {
+		super.onActivityCreated(savedInstanceState);
+		requireActivity().setRequestedOrientation(SCREEN_ORIENTATION_NOSENSOR);
+		cameraView.setPreviewConsumer(new QrCodeDecoder(this));
+	}
+
+	@Override
+	public void onStart() {
+		super.onStart();
+		try {
+			cameraView.start();
+		} catch (CameraException e) {
+			logCameraExceptionAndFinish(e);
+		}
+		startListening();
+	}
+
+	@Override
+	public void setFullscreen(boolean fullscreen) {
+		LinearLayout.LayoutParams statusParams, qrCodeParams;
+		if (fullscreen) {
+			// Grow the QR code view to fill its parent
+			statusParams = new LinearLayout.LayoutParams(0, 0, 0f);
+			qrCodeParams = new LinearLayout.LayoutParams(MATCH_PARENT, MATCH_PARENT, 1f);
+		} else {
+			// Shrink the QR code view to fill half its parent
+			if (cameraOverlay.getOrientation() == HORIZONTAL) {
+				statusParams = new LinearLayout.LayoutParams(0, MATCH_PARENT, 1f);
+				qrCodeParams = new LinearLayout.LayoutParams(0, MATCH_PARENT, 1f);
+			} else {
+				statusParams = new LinearLayout.LayoutParams(MATCH_PARENT, 0, 1f);
+				qrCodeParams = new LinearLayout.LayoutParams(MATCH_PARENT, 0, 1f);
+			}
+		}
+		statusView.setLayoutParams(statusParams);
+		qrCodeView.setLayoutParams(qrCodeParams);
+		cameraOverlay.invalidate();
+	}
+
+	@Override
+	public void onStop() {
+		super.onStop();
+		stopListening();
+		try {
+			cameraView.stop();
+		} catch (CameraException e) {
+			logCameraExceptionAndFinish(e);
+		}
+	}
+
+	@UiThread
+	private void logCameraExceptionAndFinish(CameraException e) {
+		logException(LOG, WARNING, e);
+		Toast.makeText(getActivity(), R.string.camera_error,
+				LENGTH_LONG).show();
+		finish();
+	}
+
+	@UiThread
+	private void startListening() {
+		KeyAgreementTask oldTask = task;
+		KeyAgreementTask newTask = keyAgreementTaskProvider.get();
+		task = newTask;
+		ioExecutor.execute(() -> {
+			if (oldTask != null) oldTask.stopListening();
+			newTask.listen();
+		});
+	}
+
+	@UiThread
+	private void stopListening() {
+		KeyAgreementTask oldTask = task;
+		ioExecutor.execute(() -> {
+			if (oldTask != null) oldTask.stopListening();
+		});
+	}
+
+	@UiThread
+	private void reset() {
+		// If we've stopped the camera view, restart it
+		if (gotRemotePayload) {
+			try {
+				cameraView.start();
+			} catch (CameraException e) {
+				logCameraExceptionAndFinish(e);
+				return;
+			}
+		}
+		statusView.setVisibility(INVISIBLE);
+		cameraView.setVisibility(VISIBLE);
+		gotRemotePayload = false;
+		gotLocalPayload = false;
+		startListening();
+	}
+
+	@UiThread
+	private void qrCodeScanned(String content) {
+		try {
+			byte[] payloadBytes = content.getBytes(ISO_8859_1);
+			if (LOG.isLoggable(INFO))
+				LOG.info("Remote payload is " + payloadBytes.length + " bytes");
+			Payload remotePayload = payloadParser.parse(payloadBytes);
+			gotRemotePayload = true;
+			cameraView.stop();
+			cameraView.setVisibility(INVISIBLE);
+			statusView.setVisibility(VISIBLE);
+			status.setText(R.string.connecting_to_device);
+			task.connectAndRunProtocol(remotePayload);
+		} catch (UnsupportedVersionException e) {
+			reset();
+			String msg;
+			if (e.isTooOld()) {
+				msg = getString(R.string.qr_code_too_old,
+						getString(R.string.app_name));
+			} else {
+				msg = getString(R.string.qr_code_too_new,
+						getString(R.string.app_name));
+			}
+			showNextFragment(ContactExchangeErrorFragment.newInstance(msg));
+		} catch (CameraException e) {
+			logCameraExceptionAndFinish(e);
+		} catch (IOException | IllegalArgumentException e) {
+			LOG.log(WARNING, "QR Code Invalid", e);
+			reset();
+			Toast.makeText(getActivity(), R.string.qr_code_invalid,
+					LENGTH_LONG).show();
+		}
+	}
+
+	@Override
+	public void eventOccurred(Event e) {
+		if (e instanceof KeyAgreementListeningEvent) {
+			KeyAgreementListeningEvent event = (KeyAgreementListeningEvent) e;
+			gotLocalPayload = true;
+			setQrCode(event.getLocalPayload());
+		} else if (e instanceof KeyAgreementFailedEvent) {
+			keyAgreementFailed();
+		} else if (e instanceof KeyAgreementWaitingEvent) {
+			keyAgreementWaiting();
+		} else if (e instanceof KeyAgreementStartedEvent) {
+			keyAgreementStarted();
+		} else if (e instanceof KeyAgreementAbortedEvent) {
+			KeyAgreementAbortedEvent event = (KeyAgreementAbortedEvent) e;
+			keyAgreementAborted(event.didRemoteAbort());
+		} else if (e instanceof KeyAgreementFinishedEvent) {
+			keyAgreementFinished(((KeyAgreementFinishedEvent) e).getResult());
+		}
+	}
+
+	@UiThread
+	private void keyAgreementFailed() {
+		reset();
+		listener.keyAgreementFailed();
+	}
+
+	@UiThread
+	private void keyAgreementWaiting() {
+		status.setText(listener.keyAgreementWaiting());
+	}
+
+	@UiThread
+	private void keyAgreementStarted() {
+		qrCodeView.setVisibility(INVISIBLE);
+		statusView.setVisibility(VISIBLE);
+		status.setText(listener.keyAgreementStarted());
+	}
+
+	@UiThread
+	private void keyAgreementAborted(boolean remoteAborted) {
+		reset();
+		listener.keyAgreementAborted(remoteAborted);
+	}
+
+	@UiThread
+	private void keyAgreementFinished(KeyAgreementResult result) {
+		statusView.setVisibility(VISIBLE);
+		status.setText(listener.keyAgreementFinished(result));
+	}
+
+	private void setQrCode(Payload localPayload) {
+		Context context = getContext();
+		if (context == null) return;
+		DisplayMetrics dm = context.getResources().getDisplayMetrics();
+		ioExecutor.execute(() -> {
+			byte[] payloadBytes = payloadEncoder.encode(localPayload);
+			if (LOG.isLoggable(INFO)) {
+				LOG.info("Local payload is " + payloadBytes.length
+						+ " bytes");
+			}
+			// Use ISO 8859-1 to encode bytes directly as a string
+			String content = new String(payloadBytes, ISO_8859_1);
+			Bitmap qrCode = QrCodeUtils.createQrCode(dm, content);
+			runOnUiThreadUnlessDestroyed(() -> qrCodeView.setQrCode(qrCode));
+		});
+	}
+
+	@Override
+	public void handleResult(Result result) {
+		runOnUiThreadUnlessDestroyed(() -> {
+			LOG.info("Got result from decoder");
+			// Ignore results until the KeyAgreementTask is ready
+			if (!gotLocalPayload) return;
+			if (!gotRemotePayload) qrCodeScanned(result.getText());
+		});
+	}
+
+	@Override
+	protected void finish() {
+		getActivity().getSupportFragmentManager().popBackStack();
+	}
+
+	@NotNullByDefault
+	interface ShardQrCodeEventListener {
+
+		@UiThread
+		void keyAgreementFailed();
+
+		// Should return a string to be displayed as status.
+		@UiThread
+		@Nullable
+		String keyAgreementWaiting();
+
+		// Should return a string to be displayed as status.
+		@UiThread
+		@Nullable
+		String keyAgreementStarted();
+
+		// Will show an error fragment.
+		@UiThread
+		void keyAgreementAborted(boolean remoteAborted);
+
+		// Should return a string to be displayed as status.
+		@UiThread
+		@Nullable
+		String keyAgreementFinished(KeyAgreementResult result);
+	}
+}

briar-api/src/main/java/org/briarproject/briar/api/keyagreement/KeyAgreementUtils.java

@@ -0,0 +1,35 @@
+package org.briarproject.briar.api.keyagreement;
+
+public class KeyAgreementUtils {
+
+	public enum BluetoothDecision {
+		/**
+		 * We haven't asked the user about Bluetooth discoverability.
+		 */
+		UNKNOWN,
+
+		/**
+		 * The device doesn't have a Bluetooth adapter.
+		 */
+		NO_ADAPTER,
+
+		/**
+		 * We're waiting for the user to accept or refuse discoverability.
+		 */
+		WAITING,
+
+		/**
+		 * The user has accepted discoverability.
+		 */
+		ACCEPTED,
+
+		/**
+		 * The user has refused discoverability.
+		 */
+		REFUSED
+	}
+
+	public enum Permission {
+		UNKNOWN, GRANTED, SHOW_RATIONALE, PERMANENTLY_DENIED
+	}
+}