Make it possible to amend list of wipers

briar-android/src/main/java/org/briarproject/briar/android/remotewipe/RemoteWipeSetupActivity.java

@@ -38,11 +38,11 @@ public class RemoteWipeSetupActivity extends BriarActivity implements
 	public void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 		setContentView(R.layout.activity_distributed_backup);
-        if (viewModel.remoteWipeIsSetup()) {
+//        if (viewModel.remoteWipeIsSetup()) {
-        	showInitialFragment(new RemoteWipeDisplayFragment());
+//        	showInitialFragment(new RemoteWipeDisplayFragment());
-        } else {
+//        } else {
 	        showInitialFragment(WiperSelectorFragment.newInstance());
-        }
+//        }
 
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/remotewipe/RemoteWipeSetupViewModel.java

@@ -45,11 +45,20 @@ public class RemoteWipeSetupViewModel extends AndroidViewModel {
 		}
 	}
 
+	public List<ContactId> getWiperContactIds() {
+		try {
+			return db.transactionWithResult(true,
+					remoteWipeManager::getWiperContactIds);
+		} catch (DbException ignored) {
+			return new ArrayList<ContactId>();
+		}
+	}
+
 	public List<String> getWiperNames() {
 		ArrayList wiperNames = new ArrayList();
 		try {
 			List<Author> wipers = db.transactionWithResult(true,
-					txn -> remoteWipeManager.getWipers(txn));
+					remoteWipeManager::getWipers);
 			for (Author wiper : wipers) {
 				wiperNames.add(wiper.getName());
 			}

briar-android/src/main/java/org/briarproject/briar/android/remotewipe/WiperSelectorFragment.java

@@ -4,6 +4,7 @@ import android.os.Bundle;
 import android.view.MenuItem;
 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;
@@ -14,9 +15,13 @@ import org.briarproject.briar.android.contactselection.ContactSelectorFragment;
 import org.briarproject.briar.android.contactselection.SelectableContactItem;
 import org.briarproject.briar.android.socialbackup.creation.CreateBackupController;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import javax.inject.Inject;
 
 import androidx.annotation.Nullable;
+import androidx.lifecycle.ViewModelProvider;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -24,6 +29,11 @@ public class WiperSelectorFragment extends ContactSelectorFragment {
 
 	public static final String TAG = WiperSelectorFragment.class.getName();
 
+	@Inject
+	ViewModelProvider.Factory viewModelFactory;
+
+	private RemoteWipeSetupViewModel viewModel;
+
 	@Inject
 	CreateBackupController controller;
 
@@ -40,12 +50,14 @@ public class WiperSelectorFragment extends ContactSelectorFragment {
 	@Override
 	public void injectFragment(ActivityComponent component) {
 		component.inject(this);
+		viewModel = new ViewModelProvider(requireActivity(), viewModelFactory)
+				.get(RemoteWipeSetupViewModel.class);
 	}
 
 	@Override
 	public void onCreate(@Nullable Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
-
+		selectedContacts.addAll(viewModel.getWiperContactIds());
 		requireActivity().setTitle(R.string.title_select_wipers);
 	}
 

briar-api/src/main/java/org/briarproject/briar/api/remotewipe/RemoteWipeManager.java

@@ -56,6 +56,8 @@ public interface RemoteWipeManager extends ConversationManager.ConversationClien
 
 	List<Author> getWipers(Transaction txn) throws DbException;
 
+	List<ContactId> getWiperContactIds(Transaction txn);
+
 	@Override
 	Collection<ConversationMessageHeader> getMessageHeaders(
 			Transaction txn, ContactId contactId) throws DbException;

briar-core/src/main/java/org/briarproject/briar/remotewipe/RemoteWipeManagerImpl.java

@@ -565,4 +565,27 @@ public class RemoteWipeManagerImpl extends ConversationClientImpl
 			throw new DbException(e);
 		}
 	}
+
+	public List<ContactId> getWiperContactIds(Transaction txn) {
+		ArrayList<ContactId> wiperContactIds = new ArrayList<>();
+		try {
+			List<Author> wipers = getWipers(txn);
+			for (Author wiper : wipers) {
+				wiperContactIds.add(authorToContactId(txn, wiper));
+			}
+		} catch (DbException ignored) {
+			// Will return an empty list
+		}
+		return wiperContactIds;
+	}
+
+	private ContactId authorToContactId(Transaction txn, Author author)
+			throws DbException {
+		ArrayList<Contact> contacts =
+				(ArrayList<Contact>) contactManager.getContacts(txn);
+		for (Contact c : contacts) {
+			if (c.getAuthor().equals(author)) return c.getId();
+		}
+		throw new DbException();
+	}
 }