Make a ReturnShardFragment, based on ContactExchangeFragment

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

@@ -91,6 +91,7 @@ import org.briarproject.briar.android.socialbackup.ShardsSentFragment;
 import org.briarproject.briar.android.socialbackup.ThresholdSelectorFragment;
 import org.briarproject.briar.android.socialbackup.creation.CreateBackupModule;
 import org.briarproject.briar.android.socialbackup.recover.ReturnShardActivity;
+import org.briarproject.briar.android.socialbackup.recover.ReturnShardFragment;
 import org.briarproject.briar.android.splash.SplashScreenActivity;
 import org.briarproject.briar.android.test.TestDataActivity;
 
@@ -276,4 +277,6 @@ public interface ActivityComponent {
 	void inject(ExistingBackupFragment existingBackupFragment);
 
 	void inject(NewOrRecoverFragment newOrRecoverFragment);
+
+	void inject(ReturnShardFragment returnShardFragment);
 }

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

@@ -2,7 +2,7 @@ package org.briarproject.briar.android.contact.add.nearby;
 
 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/socialbackup/recover/ReturnShardActivity.java

@@ -14,12 +14,10 @@ import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BaseActivity;
 import org.briarproject.briar.android.contact.add.nearby.AddNearbyContactErrorFragment;
-import org.briarproject.briar.android.contact.add.nearby.AddNearbyContactFragment;
 import org.briarproject.briar.android.contact.add.nearby.AddNearbyContactPermissionManager;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.util.RequestBluetoothDiscoverable;
 import org.briarproject.briar.api.socialbackup.BackupPayload;
-import org.briarproject.briar.api.socialbackup.MessageParser;
 import org.briarproject.briar.api.socialbackup.ReturnShardPayload;
 import org.briarproject.briar.api.socialbackup.Shard;
 
@@ -208,8 +206,8 @@ public class ReturnShardActivity extends BaseActivity
 	private void showQrCodeFragment() {
 		// FIXME #824
 		FragmentManager fm = getSupportFragmentManager();
-		if (fm.findFragmentByTag(AddNearbyContactFragment.TAG) == null) {
+		if (fm.findFragmentByTag(ReturnShardFragment.TAG) == null) {
-			BaseFragment f = AddNearbyContactFragment.newInstance();
+			BaseFragment f = ReturnShardFragment.newInstance();
 			fm.beginTransaction()
 					.replace(R.id.fragmentContainer, f, f.getUniqueTag())
 					.addToBackStack(f.getUniqueTag())

briar-android/src/main/java/org/briarproject/briar/android/socialbackup/recover/ReturnShardFragment.java

@@ -0,0 +1,198 @@
+package org.briarproject.briar.android.socialbackup.recover;
+
+import android.graphics.Bitmap;
+import android.os.Bundle;
+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 org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.activity.ActivityComponent;
+import org.briarproject.briar.android.contact.add.nearby.CameraException;
+import org.briarproject.briar.android.contact.add.nearby.CameraView;
+import org.briarproject.briar.android.fragment.BaseFragment;
+import org.briarproject.briar.android.view.QrCodeView;
+
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+import javax.inject.Inject;
+
+import androidx.annotation.UiThread;
+import androidx.lifecycle.ViewModelProvider;
+
+import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_NOSENSOR;
+import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
+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.WARNING;
+import static org.briarproject.bramble.util.LogUtils.logException;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+public class ReturnShardFragment extends BaseFragment
+		implements QrCodeView.FullscreenListener {
+
+	public static final String TAG = org.briarproject.briar.android.contact.add.nearby.AddNearbyContactFragment.class.getName();
+
+	private static final Logger LOG = Logger.getLogger(TAG);
+
+	@Inject
+	ViewModelProvider.Factory viewModelFactory;
+
+	private ReturnShardViewModel viewModel;
+	private CameraView cameraView;
+	private LinearLayout cameraOverlay;
+	private View statusView;
+	private QrCodeView qrCodeView;
+	private TextView status;
+
+	public static ReturnShardFragment newInstance() {
+		Bundle args = new Bundle();
+		ReturnShardFragment fragment = new ReturnShardFragment();
+		fragment.setArguments(args);
+		return fragment;
+	}
+
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+		viewModel = new ViewModelProvider(requireActivity(), viewModelFactory)
+				.get(ReturnShardViewModel.class);
+	}
+
+	@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);
+
+		viewModel.getState().observe(getViewLifecycleOwner(),
+				this::onReturnShardStateChanged);
+	}
+
+	@Override
+	public void onActivityCreated(@Nullable Bundle savedInstanceState) {
+		super.onActivityCreated(savedInstanceState);
+		requireActivity().setRequestedOrientation(SCREEN_ORIENTATION_NOSENSOR);
+		cameraView.setPreviewConsumer(viewModel.getQrCodeDecoder());
+	}
+
+	@Override
+	public void onStart() {
+		super.onStart();
+		try {
+			cameraView.start();
+		} catch (CameraException e) {
+			logCameraExceptionAndFinish(e);
+		}
+	}
+
+	@Override
+	public void onStop() {
+		super.onStop();
+		try {
+			cameraView.stop();
+		} catch (CameraException e) {
+			logCameraExceptionAndFinish(e);
+		}
+	}
+
+	@Override
+	public void onDestroy() {
+		requireActivity()
+				.setRequestedOrientation(SCREEN_ORIENTATION_UNSPECIFIED);
+		super.onDestroy();
+	}
+
+	@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();
+	}
+
+	@UiThread
+	private void onReturnShardStateChanged(@Nullable ReturnShardState state) {
+		if (state instanceof ReturnShardState.KeyAgreementListening) {
+			Bitmap qrCode =
+					((ReturnShardState.KeyAgreementListening) state).qrCode;
+			qrCodeView.setQrCode(qrCode);
+		} else if (state instanceof ReturnShardState.QrCodeScanned) {
+			try {
+				cameraView.stop();
+			} catch (CameraException e) {
+				logCameraExceptionAndFinish(e);
+			}
+			cameraView.setVisibility(INVISIBLE);
+			statusView.setVisibility(VISIBLE);
+			status.setText(R.string.connecting_to_device);
+		} else if (state instanceof ReturnShardState.KeyAgreementWaiting) {
+			status.setText(R.string.waiting_for_contact_to_scan);
+		} else if (state instanceof ReturnShardState.KeyAgreementStarted) {
+			qrCodeView.setVisibility(INVISIBLE);
+			status.setText(R.string.authenticating_with_device);
+		} else if (state instanceof ReturnShardState.SocialBackupExchangeStarted) {
+			status.setText(R.string.exchanging_contact_details);
+		} else if (state instanceof ReturnShardState.Failed) {
+			// the activity will replace this fragment with an error fragment
+			statusView.setVisibility(INVISIBLE);
+			cameraView.setVisibility(INVISIBLE);
+		}
+	}
+
+	@Override
+	public String getUniqueTag() {
+		return TAG;
+	}
+
+	@UiThread
+	private void logCameraExceptionAndFinish(CameraException e) {
+		logException(LOG, WARNING, e);
+		Toast.makeText(getActivity(), R.string.camera_error,
+				LENGTH_LONG).show();
+		finish();
+	}
+
+	@Override
+	protected void finish() {
+		requireActivity().getSupportFragmentManager().popBackStack();
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/socialbackup/recover/ReturnShardViewModel.java

@@ -410,7 +410,7 @@ class ReturnShardViewModel extends AndroidViewModel
 	@Override
 	@IoExecutor
 	public void onQrCodeDecoded(Result result) {
-		LOG.info("Got result from decoder");
+		LOG.info("Got result from decoder"+gotLocalPayload+gotRemotePayload);
 		// Ignore results until the KeyAgreementTask is ready
 		if (!gotLocalPayload || gotRemotePayload) return;
 		try {
@@ -538,4 +538,8 @@ class ReturnShardViewModel extends AndroidViewModel
     public void setReturnShardPayload(ReturnShardPayload returnShardPayload) {
 		this.returnShardPayload = returnShardPayload;
     }
+
+	QrCodeDecoder getQrCodeDecoder() {
+		return qrCodeDecoder;
+	}
 }