Merge branch '631-inject-fragments-early' into 'master'

Inject fragments earlier in their lifecycle

Closes #631

See merge request briar/briar!1024

briar-android/src/main/java/org/briarproject/briar/android/StartupFailureActivity.java

@@ -3,22 +3,29 @@ package org.briarproject.briar.android;
 import android.app.NotificationManager;
 import android.content.Intent;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
+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.activity.BaseActivity;
 import org.briarproject.briar.android.fragment.BaseFragment.BaseFragmentListener;
 import org.briarproject.briar.android.fragment.ErrorFragment;
 
+import static java.util.Objects.requireNonNull;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult;
 import static org.briarproject.briar.android.BriarService.EXTRA_NOTIFICATION_ID;
 import static org.briarproject.briar.android.BriarService.EXTRA_START_RESULT;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public class StartupFailureActivity extends BaseActivity implements
 		BaseFragmentListener {
 
 	@Override
-	public void onCreate(Bundle state) {
+	public void onCreate(@Nullable Bundle state) {
 		super.onCreate(state);
 
 		setContentView(R.layout.activity_fragment_container);
@@ -38,7 +45,7 @@ public class StartupFailureActivity extends BaseActivity implements
 		// cancel notification
 		if (notificationId > -1) {
 			Object o = getSystemService(NOTIFICATION_SERVICE);
-			NotificationManager nm = (NotificationManager) o;
+			NotificationManager nm = (NotificationManager) requireNonNull(o);
 			nm.cancel(notificationId);
 		}
 
@@ -66,7 +73,7 @@ public class StartupFailureActivity extends BaseActivity implements
 	}
 
 	@Override
-	public void runOnDbThread(Runnable runnable) {
+	public void runOnDbThread(@NonNull Runnable runnable) {
 		throw new AssertionError("Deprecated and should not be used");
 	}
 

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

@@ -31,7 +31,6 @@ import org.briarproject.briar.android.introduction.IntroductionActivity;
 import org.briarproject.briar.android.introduction.IntroductionMessageFragment;
 import org.briarproject.briar.android.keyagreement.ContactExchangeActivity;
 import org.briarproject.briar.android.keyagreement.ContactExchangeErrorFragment;
-import org.briarproject.briar.android.keyagreement.IntroFragment;
 import org.briarproject.briar.android.keyagreement.KeyAgreementActivity;
 import org.briarproject.briar.android.keyagreement.KeyAgreementFragment;
 import org.briarproject.briar.android.login.AuthorNameFragment;
@@ -49,7 +48,6 @@ import org.briarproject.briar.android.privategroup.conversation.GroupActivity;
 import org.briarproject.briar.android.privategroup.conversation.GroupConversationModule;
 import org.briarproject.briar.android.privategroup.creation.CreateGroupActivity;
 import org.briarproject.briar.android.privategroup.creation.CreateGroupFragment;
-import org.briarproject.briar.android.privategroup.creation.CreateGroupMessageFragment;
 import org.briarproject.briar.android.privategroup.creation.CreateGroupModule;
 import org.briarproject.briar.android.privategroup.creation.GroupInviteActivity;
 import org.briarproject.briar.android.privategroup.creation.GroupInviteFragment;
@@ -70,10 +68,8 @@ import org.briarproject.briar.android.sharing.ForumInvitationActivity;
 import org.briarproject.briar.android.sharing.ForumSharingStatusActivity;
 import org.briarproject.briar.android.sharing.ShareBlogActivity;
 import org.briarproject.briar.android.sharing.ShareBlogFragment;
-import org.briarproject.briar.android.sharing.ShareBlogMessageFragment;
 import org.briarproject.briar.android.sharing.ShareForumActivity;
 import org.briarproject.briar.android.sharing.ShareForumFragment;
-import org.briarproject.briar.android.sharing.ShareForumMessageFragment;
 import org.briarproject.briar.android.sharing.SharingModule;
 import org.briarproject.briar.android.splash.SplashScreenActivity;
 import org.briarproject.briar.android.test.TestDataActivity;
@@ -183,8 +179,6 @@ public interface ActivityComponent {
 
 	void inject(CreateGroupFragment fragment);
 
-	void inject(CreateGroupMessageFragment fragment);
-
 	void inject(GroupListFragment fragment);
 
 	void inject(GroupInviteFragment fragment);
@@ -195,20 +189,14 @@ public interface ActivityComponent {
 
 	void inject(FeedFragment fragment);
 
-	void inject(IntroFragment fragment);
-
 	void inject(KeyAgreementFragment fragment);
 
 	void inject(ContactChooserFragment fragment);
 
 	void inject(ShareForumFragment fragment);
 
-	void inject(ShareForumMessageFragment fragment);
-
 	void inject(ShareBlogFragment fragment);
 
-	void inject(ShareBlogMessageFragment fragment);
-
 	void inject(IntroductionMessageFragment fragment);
 
 	void inject(SettingsFragment fragment);

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

@@ -15,6 +15,8 @@ import android.view.ViewGroup.LayoutParams;
 import android.view.inputmethod.InputMethodManager;
 
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.AndroidComponent;
 import org.briarproject.briar.android.BriarApplication;
@@ -51,6 +53,8 @@ import static org.briarproject.briar.android.TestingConstants.PREVENT_SCREENSHOT
  * Warning: Some activities don't extend {@link BaseActivity}.
  *          E.g. {@link DevReportActivity}
  */
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public abstract class BaseActivity extends AppCompatActivity
 		implements DestroyableContext, OnTapFilteredListener {
 
@@ -77,6 +81,17 @@ public abstract class BaseActivity extends AppCompatActivity
 
 	@Override
 	public void onCreate(@Nullable Bundle state) {
+		// create the ActivityComponent *before* calling super.onCreate()
+		// because it already attaches fragments which need access
+		// to the component for their own injection
+		AndroidComponent applicationComponent =
+				((BriarApplication) getApplication()).getApplicationComponent();
+		activityComponent = DaggerActivityComponent.builder()
+				.androidComponent(applicationComponent)
+				.activityModule(getActivityModule())
+				.forumModule(getForumModule())
+				.build();
+		injectActivity(activityComponent);
 		super.onCreate(state);
 
 		// WARNING: When removing this or making it possible to turn it off,
@@ -86,17 +101,6 @@ public abstract class BaseActivity extends AppCompatActivity
 		//          unlock screen is shown.
 		if (PREVENT_SCREENSHOTS) getWindow().addFlags(FLAG_SECURE);
 
-		AndroidComponent applicationComponent =
-				((BriarApplication) getApplication()).getApplicationComponent();
-
-		activityComponent = DaggerActivityComponent.builder()
-				.androidComponent(applicationComponent)
-				.activityModule(getActivityModule())
-				.forumModule(getForumModule())
-				.build();
-
-		injectActivity(activityComponent);
-
 		for (ActivityLifecycleController alc : lifecycleControllers) {
 			alc.onActivityCreate(this);
 		}

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

@@ -1,6 +1,5 @@
 package org.briarproject.briar.android.activity;
 
-import android.annotation.SuppressLint;
 import android.content.Intent;
 import android.support.annotation.RequiresApi;
 import android.support.v7.app.ActionBar;
@@ -10,6 +9,8 @@ import android.transition.Transition;
 import android.view.Window;
 import android.widget.CheckBox;
 
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.controller.BriarController;
 import org.briarproject.briar.android.controller.DbController;
@@ -36,7 +37,8 @@ import static org.briarproject.briar.android.util.UiUtils.excludeSystemUi;
 import static org.briarproject.briar.android.util.UiUtils.getDozeWhitelistingIntent;
 import static org.briarproject.briar.android.util.UiUtils.isSamsung7;
 
-@SuppressLint("Registered")
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public abstract class BriarActivity extends BaseActivity {
 
 	public static final String GROUP_ID = "briar.GROUP_ID";
@@ -60,7 +62,8 @@ public abstract class BriarActivity extends BaseActivity {
 	}
 
 	@Override
-	protected void onActivityResult(int request, int result, Intent data) {
+	protected void onActivityResult(int request, int result,
+			@Nullable Intent data) {
 		super.onActivityResult(request, result, data);
 		if (request == REQUEST_PASSWORD) {
 			// The result can be RESULT_CANCELED if there's no account

briar-android/src/main/java/org/briarproject/briar/android/blog/BasePostFragment.java

@@ -24,6 +24,8 @@ import javax.annotation.Nullable;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
+import static java.util.Objects.requireNonNull;
+import static java.util.logging.Logger.getLogger;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 import static org.briarproject.briar.android.util.UiUtils.MIN_DATE_RESOLUTION;
 
@@ -35,7 +37,7 @@ abstract class BasePostFragment extends BaseFragment {
 	static final String POST_ID = "briar.POST_ID";
 
 	private static final Logger LOG =
-			Logger.getLogger(BasePostFragment.class.getName());
+			getLogger(BasePostFragment.class.getName());
 
 	private final Handler handler = new Handler(Looper.getMainLooper());
 
@@ -52,7 +54,7 @@ abstract class BasePostFragment extends BaseFragment {
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
 		// retrieve MessageId of blog post from arguments
-		byte[] p = getArguments().getByteArray(POST_ID);
+		byte[] p = requireNonNull(getArguments()).getByteArray(POST_ID);
 		if (p == null) throw new IllegalStateException("No post ID in args");
 		postId = new MessageId(p);
 
@@ -68,6 +70,7 @@ abstract class BasePostFragment extends BaseFragment {
 
 			@Override
 			public void onAuthorClick(BlogPostItem post) {
+				if (getContext() == null) return;
 				Intent i = new Intent(getContext(), BlogActivity.class);
 				i.putExtra(GROUP_ID, post.getGroupId().getBytes());
 				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP);

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogFragment.java

@@ -43,6 +43,7 @@ import javax.inject.Inject;
 import static android.app.Activity.RESULT_OK;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
 import static android.widget.Toast.LENGTH_SHORT;
+import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_SHARE_BLOG;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_WRITE_BLOG_POST;
@@ -69,7 +70,6 @@ public class BlogFragment extends BaseFragment
 	private boolean isMyBlog = false, canDeleteBlog = false;
 
 	static BlogFragment newInstance(GroupId groupId) {
-
 		BlogFragment f = new BlogFragment();
 
 		Bundle bundle = new Bundle();
@@ -79,20 +79,27 @@ public class BlogFragment extends BaseFragment
 		return f;
 	}
 
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+		blogController.setBlogSharingListener(this);
+		sharingController.setSharingListener(this);
+	}
+
 	@Nullable
 	@Override
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
-		Bundle args = getArguments();
+		Bundle args = requireNonNull(getArguments());
 		byte[] b = args.getByteArray(GROUP_ID);
 		if (b == null) throw new IllegalStateException("No group ID in args");
 		groupId = new GroupId(b);
 
 		View v = inflater.inflate(R.layout.fragment_blog, container, false);
 
-		adapter =
-				new BlogPostAdapter(getActivity(), this, getFragmentManager());
+		adapter = new BlogPostAdapter(requireNonNull(getActivity()), this,
+				getFragmentManager());
 		list = v.findViewById(R.id.postList);
 		list.setLayoutManager(new LinearLayoutManager(getActivity()));
 		list.setAdapter(adapter);
@@ -102,13 +109,6 @@ public class BlogFragment extends BaseFragment
 		return v;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-		blogController.setBlogSharingListener(this);
-		sharingController.setSharingListener(this);
-	}
-
 	@Override
 	public void onStart() {
 		super.onStart();
@@ -218,7 +218,10 @@ public class BlogFragment extends BaseFragment
 
 	@Override
 	public void onAuthorClick(BlogPostItem post) {
-		if (post.getGroupId().equals(groupId)) return; // We're already there
+		if (post.getGroupId().equals(groupId) || getContext() == null) {
+			// We're already there
+			return;
+		}
 		Intent i = new Intent(getContext(), BlogActivity.class);
 		i.putExtra(GROUP_ID, post.getGroupId().getBytes());
 		i.setFlags(FLAG_ACTIVITY_CLEAR_TOP);

briar-android/src/main/java/org/briarproject/briar/android/blog/FeedFragment.java

@@ -35,6 +35,7 @@ import javax.inject.Inject;
 import static android.app.Activity.RESULT_OK;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
 import static android.support.design.widget.Snackbar.LENGTH_LONG;
+import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_WRITE_BLOG_POST;
 
@@ -64,13 +65,18 @@ public class FeedFragment extends BaseFragment implements
 		return f;
 	}
 
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+		feedController.setFeedListener(this);
+	}
+
 	@Nullable
 	@Override
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
-
-		getActivity().setTitle(R.string.blogs_button);
+		requireNonNull(getActivity()).setTitle(R.string.blogs_button);
 
 		View v = inflater.inflate(R.layout.fragment_blog, container, false);
 
@@ -88,12 +94,6 @@ public class FeedFragment extends BaseFragment implements
 		return v;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-		feedController.setFeedListener(this);
-	}
-
 	@Override
 	public void onActivityResult(int requestCode, int resultCode, Intent data) {
 		super.onActivityResult(requestCode, resultCode, data);

briar-android/src/main/java/org/briarproject/briar/android/blog/FeedPostFragment.java

@@ -17,6 +17,7 @@ import org.briarproject.briar.android.controller.handler.UiResultExceptionHandle
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 
 @UiThread
@@ -42,13 +43,17 @@ public class FeedPostFragment extends BasePostFragment {
 		return f;
 	}
 
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+	}
+
 	@Nullable
 	@Override
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
-
-		Bundle args = getArguments();
+		Bundle args = requireNonNull(getArguments());
 		byte[] b = args.getByteArray(GROUP_ID);
 		if (b == null) throw new IllegalStateException("No group ID in args");
 		blogId = new GroupId(b);
@@ -61,11 +66,6 @@ public class FeedPostFragment extends BasePostFragment {
 		return TAG;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-	}
-
 	@Override
 	public void onStart() {
 		super.onStart();

briar-android/src/main/java/org/briarproject/briar/android/blog/ReblogFragment.java

@@ -31,6 +31,7 @@ import static android.view.View.FOCUS_DOWN;
 import static android.view.View.GONE;
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
+import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 import static org.briarproject.briar.android.blog.BasePostFragment.POST_ID;
 import static org.briarproject.briar.api.blog.BlogConstants.MAX_BLOG_POST_TEXT_LENGTH;
@@ -42,8 +43,6 @@ public class ReblogFragment extends BaseFragment implements SendListener {
 	public static final String TAG = ReblogFragment.class.getName();
 
 	private ViewHolder ui;
-	private GroupId blogId;
-	private MessageId postId;
 	private BlogPostItem item;
 
 	@Inject
@@ -75,9 +74,11 @@ public class ReblogFragment extends BaseFragment implements SendListener {
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
 
-		Bundle args = getArguments();
-		blogId = new GroupId(args.getByteArray(GROUP_ID));
-		postId = new MessageId(args.getByteArray(POST_ID));
+		Bundle args = requireNonNull(getArguments());
+		GroupId blogId =
+				new GroupId(requireNonNull(args.getByteArray(GROUP_ID)));
+		MessageId postId =
+				new MessageId(requireNonNull(args.getByteArray(POST_ID)));
 
 		View v = inflater.inflate(R.layout.fragment_reblog, container, false);
 		ui = new ViewHolder(v);
@@ -89,14 +90,6 @@ public class ReblogFragment extends BaseFragment implements SendListener {
 		ui.input.setMaxTextLength(MAX_BLOG_POST_TEXT_LENGTH);
 		showProgressBar();
 
-		return v;
-	}
-
-	@Override
-	public void onStart() {
-		super.onStart();
-
-		// TODO: Load blog post when fragment is created. #631
 		feedController.loadBlogPost(blogId, postId,
 				new UiResultExceptionHandler<BlogPostItem, DbException>(
 						this) {
@@ -111,6 +104,8 @@ public class ReblogFragment extends BaseFragment implements SendListener {
 						handleDbException(exception);
 					}
 				});
+
+		return v;
 	}
 
 	private void bindViewHolder() {

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListFragment.java

@@ -51,6 +51,7 @@ import javax.inject.Inject;
 import static android.os.Build.VERSION.SDK_INT;
 import static android.support.v4.app.ActivityOptionsCompat.makeSceneTransitionAnimation;
 import static android.support.v4.view.ViewCompat.getTransitionName;
+import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
@@ -102,8 +103,7 @@ public class ContactListFragment extends BaseFragment implements EventListener {
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
-
-		getActivity().setTitle(R.string.contact_list_button);
+		requireNonNull(getActivity()).setTitle(R.string.contact_list_button);
 
 		View contentView = inflater.inflate(R.layout.list, container, false);
 

briar-android/src/main/java/org/briarproject/briar/android/contactselection/BaseContactSelectorFragment.java

@@ -25,6 +25,7 @@ import java.util.Collection;
 
 import javax.annotation.Nullable;
 
+import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 import static org.briarproject.briar.android.contactselection.ContactSelectorActivity.CONTACTS;
 import static org.briarproject.briar.android.contactselection.ContactSelectorActivity.getContactsFromIds;
@@ -50,10 +51,10 @@ public abstract class BaseContactSelectorFragment<I extends SelectableContactIte
 	}
 
 	@Override
-	public void onCreate(Bundle savedInstanceState) {
+	public void onCreate(@Nullable Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 
-		Bundle args = getArguments();
+		Bundle args = requireNonNull(getArguments());
 		byte[] b = args.getByteArray(GROUP_ID);
 		if (b == null) throw new IllegalStateException("No GroupId");
 		groupId = new GroupId(b);
@@ -72,7 +73,7 @@ public abstract class BaseContactSelectorFragment<I extends SelectableContactIte
 		list.setEmptyImage(R.drawable.ic_empty_state_contact_list);
 		list.setEmptyText(getString(R.string.no_contacts_selector));
 		list.setEmptyAction(getString(R.string.no_contacts_selector_action));
-		adapter = getAdapter(getContext(), this);
+		adapter = getAdapter(requireNonNull(getContext()), this);
 		list.setAdapter(adapter);
 
 		// restore selected contacts if available

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

@@ -15,7 +15,6 @@ import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.BriarActivity;
 
-import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import static java.util.Objects.requireNonNull;
@@ -29,7 +28,6 @@ public class AliasDialogFragment extends AppCompatDialogFragment {
 
 	private ConversationViewModel viewModel;
 	private EditText aliasEditText;
-	private Button setButton;
 
 	public static AliasDialogFragment newInstance() {
 		return new AliasDialogFragment();
@@ -40,6 +38,11 @@ public class AliasDialogFragment extends AppCompatDialogFragment {
 		super.onCreate(savedInstanceState);
 
 		setStyle(STYLE_NO_TITLE, R.style.BriarDialogTheme);
+
+		BriarActivity a = (BriarActivity) requireNonNull(getActivity());
+		a.getActivityComponent().inject(this);
+		viewModel = ViewModelProviders.of(getActivity(), viewModelFactory)
+				.get(ConversationViewModel.class);
 	}
 
 	@Override
@@ -47,8 +50,18 @@ public class AliasDialogFragment extends AppCompatDialogFragment {
 			ViewGroup container, Bundle savedInstanceState) {
 		View v = inflater.inflate(R.layout.fragment_alias_dialog, container,
 				false);
+
 		aliasEditText = v.findViewById(R.id.aliasEditText);
-		setButton = v.findViewById(R.id.setButton);
+		Contact contact = requireNonNull(viewModel.getContact().getValue());
+		String alias = contact.getAlias();
+		aliasEditText.setText(alias);
+		if (alias != null) aliasEditText.setSelection(alias.length());
+
+		Button setButton = v.findViewById(R.id.setButton);
+		setButton.setOnClickListener(v1 -> {
+			viewModel.setContactAlias(aliasEditText.getText().toString());
+			getDialog().dismiss();
+		});
 
 		Button cancelButton = v.findViewById(R.id.cancelButton);
 		cancelButton.setOnClickListener(v1 -> getDialog().cancel());
@@ -56,24 +69,4 @@ public class AliasDialogFragment extends AppCompatDialogFragment {
 		return v;
 	}
 
-	@Override
-	public void onActivityCreated(@Nullable Bundle savedInstanceState) {
-		super.onActivityCreated(savedInstanceState);
-		BriarActivity a = (BriarActivity) requireNonNull(getActivity());
-		a.getActivityComponent().inject(this);
-
-		viewModel = ViewModelProviders.of(getActivity(), viewModelFactory)
-				.get(ConversationViewModel.class);
-
-		Contact contact = requireNonNull(viewModel.getContact().getValue());
-		String alias = contact.getAlias();
-		aliasEditText.setText(alias);
-		if (alias != null) aliasEditText.setSelection(alias.length());
-
-		setButton.setOnClickListener(v1 -> {
-			viewModel.setContactAlias(aliasEditText.getText().toString());
-			getDialog().dismiss();
-		});
-	}
-
 }

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumListFragment.java

@@ -44,6 +44,7 @@ import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import static android.support.design.widget.Snackbar.LENGTH_INDEFINITE;
+import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
@@ -80,13 +81,18 @@ public class ForumListFragment extends BaseEventFragment implements
 		return fragment;
 	}
 
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+	}
+
 	@Nullable
 	@Override
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
 
-		getActivity().setTitle(R.string.forums_button);
+		requireNonNull(getActivity()).setTitle(R.string.forums_button);
 
 		View contentView =
 				inflater.inflate(R.layout.fragment_forum_list, container,
@@ -102,7 +108,7 @@ public class ForumListFragment extends BaseEventFragment implements
 		snackbar.getView().setBackgroundResource(R.color.briar_primary);
 		snackbar.setAction(R.string.show, this);
 		snackbar.setActionTextColor(ContextCompat
-				.getColor(getContext(), R.color.briar_button_text_positive));
+				.getColor(getActivity(), R.color.briar_button_text_positive));
 
 		return contentView;
 	}
@@ -112,11 +118,6 @@ public class ForumListFragment extends BaseEventFragment implements
 		return TAG;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-	}
-
 	@Override
 	public void onStart() {
 		super.onStart();

briar-android/src/main/java/org/briarproject/briar/android/fragment/BaseFragment.java

@@ -10,11 +10,15 @@ import android.support.v4.app.FragmentActivity;
 import android.view.MenuItem;
 
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.android.DestroyableContext;
 import org.briarproject.briar.android.activity.ActivityComponent;
 
 import javax.annotation.Nullable;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public abstract class BaseFragment extends Fragment
 		implements DestroyableContext {
 
@@ -22,12 +26,15 @@ public abstract class BaseFragment extends Fragment
 
 	public abstract String getUniqueTag();
 
-	public abstract void injectFragment(ActivityComponent component);
-
 	@Override
 	public void onAttach(Context context) {
 		super.onAttach(context);
 		listener = (BaseFragmentListener) context;
+		injectFragment(listener.getActivityComponent());
+	}
+
+	public void injectFragment(ActivityComponent component) {
+		// fragments that need to inject, can override this method
 	}
 
 	@Override
@@ -38,12 +45,6 @@ public abstract class BaseFragment extends Fragment
 		setHasOptionsMenu(true);
 	}
 
-	@Override
-	public void onActivityCreated(@Nullable Bundle savedInstanceState) {
-		super.onActivityCreated(savedInstanceState);
-		injectFragment(listener.getActivityComponent());
-	}
-
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item) {
 		switch (item.getItemId()) {

briar-android/src/main/java/org/briarproject/briar/android/fragment/ErrorFragment.java

@@ -10,7 +10,6 @@ import android.widget.TextView;
 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;
 
 
 @MethodsNotNullByDefault
@@ -57,9 +56,4 @@ public class ErrorFragment extends BaseFragment {
 		return v;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		// not necessary
-	}
-
 }

briar-android/src/main/java/org/briarproject/briar/android/introduction/ContactChooserFragment.java

@@ -1,7 +1,8 @@
 package org.briarproject.briar.android.introduction;
 
-import android.content.Context;
 import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.support.annotation.UiThread;
 import android.support.v7.widget.LinearLayoutManager;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -11,6 +12,8 @@ import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
@@ -28,10 +31,14 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.android.conversation.ConversationActivity.CONTACT_ID;
 
+@UiThread
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public class ContactChooserFragment extends BaseFragment {
 
 	public static final String TAG = ContactChooserFragment.class.getName();
@@ -51,7 +58,6 @@ public class ContactChooserFragment extends BaseFragment {
 	volatile ConnectionRegistry connectionRegistry;
 
 	public static ContactChooserFragment newInstance(ContactId id) {
-
 		Bundle args = new Bundle();
 
 		ContactChooserFragment fragment = new ContactChooserFragment();
@@ -61,13 +67,13 @@ public class ContactChooserFragment extends BaseFragment {
 	}
 
 	@Override
-	public void onAttach(Context context) {
-		super.onAttach(context);
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
 	}
 
 	@Override
-	public View onCreateView(LayoutInflater inflater, ViewGroup container,
-			Bundle savedInstanceState) {
+	public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
+			@Nullable Bundle savedInstanceState) {
 
 		View contentView = inflater.inflate(R.layout.list, container, false);
 
@@ -77,14 +83,16 @@ public class ContactChooserFragment extends BaseFragment {
 					Contact c2 = item.getContact();
 					showMessageScreen(c1, c2);
 				};
-		adapter = new ContactListAdapter(getActivity(), onContactClickListener);
+		adapter = new ContactListAdapter(requireNonNull(getActivity()),
+				onContactClickListener);
 
 		list = contentView.findViewById(R.id.list);
 		list.setLayoutManager(new LinearLayoutManager(getActivity()));
 		list.setAdapter(adapter);
 		list.setEmptyText(R.string.no_contacts);
 
-		contactId = new ContactId(getArguments().getInt(CONTACT_ID));
+		contactId = new ContactId(
+				requireNonNull(getArguments()).getInt(CONTACT_ID));
 
 		return contentView;
 	}
@@ -107,11 +115,6 @@ public class ContactChooserFragment extends BaseFragment {
 		return TAG;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-	}
-
 	private void loadContacts() {
 		listener.runOnDbThread(() -> {
 			try {

briar-android/src/main/java/org/briarproject/briar/android/introduction/IntroductionMessageFragment.java

@@ -39,6 +39,7 @@ import static android.app.Activity.RESULT_OK;
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 import static android.widget.Toast.LENGTH_SHORT;
+import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.android.util.UiUtils.getContactDisplayName;
@@ -77,17 +78,17 @@ public class IntroductionMessageFragment extends BaseFragment
 		return fragment;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-	}
-
 	@Override
 	public void onAttach(Context context) {
 		super.onAttach(context);
 		introductionActivity = (IntroductionActivity) context;
 	}
 
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+	}
+
 	@Override
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
@@ -99,6 +100,14 @@ public class IntroductionMessageFragment extends BaseFragment
 			actionBar.setTitle(R.string.introduction_message_title);
 		}
 
+		// get contact IDs from fragment arguments
+		Bundle args = requireNonNull(getArguments());
+		int contactId1 = args.getInt(CONTACT_ID_1, -1);
+		int contactId2 = args.getInt(CONTACT_ID_2, -1);
+		if (contactId1 == -1 || contactId2 == -1) {
+			throw new AssertionError("Use newInstance() to instantiate");
+		}
+
 		// inflate view
 		View v = inflater.inflate(R.layout.introduction_message, container,
 				false);
@@ -109,22 +118,15 @@ public class IntroductionMessageFragment extends BaseFragment
 		ui.message.setMaxTextLength(MAX_INTRODUCTION_TEXT_LENGTH);
 		ui.message.setEnabled(false);
 
+		// get contacts and then show view
+		prepareToSetUpViews(contactId1, contactId2);
+
 		return v;
 	}
 
 	@Override
 	public void onStart() {
 		super.onStart();
-
-		// get contact IDs from fragment arguments
-		int contactId1 = getArguments().getInt(CONTACT_ID_1, -1);
-		int contactId2 = getArguments().getInt(CONTACT_ID_2, -1);
-		if (contactId1 == -1 || contactId2 == -1) {
-			throw new java.lang.InstantiationError(
-					"You need to use newInstance() to instantiate");
-		}
-		// get contacts and then show view
-		prepareToSetUpViews(contactId1, contactId2);
 	}
 
 	@Override

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

@@ -44,6 +44,11 @@ public class ContactExchangeErrorFragment extends BaseFragment {
 		return TAG;
 	}
 
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+	}
+
 	@Nullable
 	@Override
 	public View onCreateView(LayoutInflater inflater,
@@ -74,11 +79,6 @@ public class ContactExchangeErrorFragment extends BaseFragment {
 		return v;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-	}
-
 	private void triggerFeedback() {
 		finish();
 		UiUtils.triggerFeedback(androidExecutor);

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

@@ -10,7 +10,6 @@ import android.widget.ScrollView;
 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.fragment.BaseFragment;
 
 import javax.annotation.Nullable;
@@ -39,11 +38,6 @@ public class IntroFragment extends BaseFragment {
 		return fragment;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-	}
-
 	@Override
 	public void onAttach(Context context) {
 		super.onAttach(context);

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

@@ -53,6 +53,7 @@ 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.Objects.requireNonNull;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
@@ -136,7 +137,8 @@ public class KeyAgreementFragment extends BaseEventFragment
 	@Override
 	public void onActivityCreated(@Nullable Bundle savedInstanceState) {
 		super.onActivityCreated(savedInstanceState);
-		getActivity().setRequestedOrientation(SCREEN_ORIENTATION_NOSENSOR);
+		requireNonNull(getActivity())
+				.setRequestedOrientation(SCREEN_ORIENTATION_NOSENSOR);
 		cameraView.setPreviewConsumer(new QrCodeDecoder(this));
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/login/AuthorNameFragment.java

@@ -18,6 +18,7 @@ import javax.annotation.Nullable;
 
 import static android.view.inputmethod.EditorInfo.IME_ACTION_NEXT;
 import static android.view.inputmethod.EditorInfo.IME_ACTION_NONE;
+import static java.util.Objects.requireNonNull;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.briar.android.util.UiUtils.setError;
 
@@ -35,11 +36,16 @@ public class AuthorNameFragment extends SetupFragment {
 		return new AuthorNameFragment();
 	}
 
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+	}
+
 	@Override
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
-		getActivity().setTitle(getString(R.string.setup_title));
+		requireNonNull(getActivity()).setTitle(getString(R.string.setup_title));
 		View v = inflater.inflate(R.layout.fragment_setup_author_name,
 				container, false);
 		authorNameWrapper = v.findViewById(R.id.nickname_entry_wrapper);
@@ -57,11 +63,6 @@ public class AuthorNameFragment extends SetupFragment {
 		return TAG;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-	}
-
 	@Override
 	protected String getHelpText() {
 		return getString(R.string.setup_name_explanation);

briar-android/src/main/java/org/briarproject/briar/android/login/DozeFragment.java

@@ -19,6 +19,7 @@ import org.briarproject.briar.android.util.UiUtils;
 
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
+import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_DOZE_WHITELISTING;
 import static org.briarproject.briar.android.util.UiUtils.showOnboardingDialog;
 
@@ -39,11 +40,16 @@ public class DozeFragment extends SetupFragment
 		return new DozeFragment();
 	}
 
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+	}
+
 	@Override
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
-		getActivity().setTitle(getString(R.string.setup_doze_title));
+		requireNonNull(getActivity()).setTitle(getString(R.string.setup_doze_title));
 		setHasOptionsMenu(false);
 		View v = inflater.inflate(R.layout.fragment_setup_doze, container,
 						false);
@@ -65,11 +71,6 @@ public class DozeFragment extends SetupFragment
 		return TAG;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-	}
-
 	@Override
 	protected String getHelpText() {
 		return getString(R.string.setup_doze_explanation);

briar-android/src/main/java/org/briarproject/briar/android/login/PasswordFragment.java

@@ -23,6 +23,7 @@ import static android.content.Context.INPUT_METHOD_SERVICE;
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
 import static android.view.inputmethod.EditorInfo.IME_ACTION_DONE;
+import static java.util.Objects.requireNonNull;
 import static org.briarproject.bramble.api.crypto.PasswordStrengthEstimator.QUITE_WEAK;
 
 @MethodsNotNullByDefault
@@ -43,11 +44,16 @@ public class PasswordFragment extends SetupFragment {
 		return new PasswordFragment();
 	}
 
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+	}
+
 	@Override
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
-		getActivity().setTitle(getString(R.string.setup_password_intro));
+		requireNonNull(getActivity()).setTitle(getString(R.string.setup_password_intro));
 		View v = inflater.inflate(R.layout.fragment_setup_password, container,
 						false);
 
@@ -64,6 +70,11 @@ public class PasswordFragment extends SetupFragment {
 		passwordConfirmation.addTextChangedListener(this);
 		nextButton.setOnClickListener(this);
 
+		if (!setupController.needToShowDozeFragment()) {
+			nextButton.setText(R.string.create_account_button);
+			passwordConfirmation.setImeOptions(IME_ACTION_DONE);
+		}
+
 		return v;
 	}
 
@@ -72,17 +83,6 @@ public class PasswordFragment extends SetupFragment {
 		return TAG;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-
-		// the controller is not yet available in onCreateView()
-		if (!setupController.needToShowDozeFragment()) {
-			nextButton.setText(R.string.create_account_button);
-			passwordConfirmation.setImeOptions(IME_ACTION_DONE);
-		}
-	}
-
 	@Override
 	protected String getHelpText() {
 		return getString(R.string.setup_password_explanation);

briar-android/src/main/java/org/briarproject/briar/android/login/SetupFragment.java

@@ -11,7 +11,8 @@ import android.view.View.OnClickListener;
 import android.widget.TextView;
 import android.widget.TextView.OnEditorActionListener;
 
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.fragment.BaseFragment;
 
@@ -22,7 +23,8 @@ import static android.view.inputmethod.EditorInfo.IME_ACTION_NEXT;
 import static org.briarproject.briar.android.util.UiUtils.enterPressed;
 import static org.briarproject.briar.android.util.UiUtils.showOnboardingDialog;
 
-@NotNullByDefault
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 abstract class SetupFragment extends BaseFragment implements TextWatcher,
 		OnEditorActionListener, OnClickListener {
 

briar-android/src/main/java/org/briarproject/briar/android/logout/SignOutFragment.java

@@ -5,19 +5,21 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
+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.fragment.BaseFragment;
 
-import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public class SignOutFragment extends BaseFragment {
 
 	public static final String TAG = SignOutFragment.class.getName();
 
 	@Override
-	public View onCreateView(@Nonnull LayoutInflater inflater,
+	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
 		return inflater.inflate(R.layout.fragment_sign_out, container, false);
@@ -27,9 +29,4 @@ public class SignOutFragment extends BaseFragment {
 	public String getUniqueTag() {
 		return TAG;
 	}
-
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		// no need to inject
-	}
 }

briar-android/src/main/java/org/briarproject/briar/android/navdrawer/NavDrawerActivity.java

@@ -5,6 +5,7 @@ import android.content.Intent;
 import android.content.res.Configuration;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.design.widget.NavigationView;
 import android.support.design.widget.NavigationView.OnNavigationItemSelectedListener;
 import android.support.v4.app.ActivityCompat;
@@ -12,6 +13,7 @@ import android.support.v4.app.FragmentManager;
 import android.support.v4.app.FragmentTransaction;
 import android.support.v4.content.ContextCompat;
 import android.support.v4.widget.DrawerLayout;
+import android.support.v7.app.ActionBar;
 import android.support.v7.app.ActionBarDrawerToggle;
 import android.support.v7.widget.Toolbar;
 import android.view.LayoutInflater;
@@ -25,6 +27,8 @@ import android.widget.TextView;
 
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.BluetoothConstants;
 import org.briarproject.bramble.api.plugin.LanTcpConstants;
 import org.briarproject.bramble.api.plugin.TorConstants;
@@ -54,6 +58,7 @@ import static android.support.v4.view.GravityCompat.START;
 import static android.support.v4.widget.DrawerLayout.LOCK_MODE_LOCKED_CLOSED;
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
+import static java.util.Objects.requireNonNull;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.RUNNING;
 import static org.briarproject.briar.android.BriarService.EXTRA_STARTUP_FAILED;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_PASSWORD;
@@ -61,6 +66,8 @@ import static org.briarproject.briar.android.navdrawer.NavDrawerController.Expir
 import static org.briarproject.briar.android.navdrawer.NavDrawerController.ExpiryWarning.UPDATE;
 import static org.briarproject.briar.android.util.UiUtils.getDaysUntilExpiry;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public class NavDrawerActivity extends BriarActivity implements
 		BaseFragmentListener, TransportStateListener,
 		OnNavigationItemSelectedListener {
@@ -112,9 +119,8 @@ public class NavDrawerActivity extends BriarActivity implements
 		component.inject(this);
 	}
 
-	@SuppressWarnings("ConstantConditions")
 	@Override
-	public void onCreate(Bundle state) {
+	public void onCreate(@Nullable Bundle state) {
 		super.onCreate(state);
 		exitIfStartupFailed(getIntent());
 		setContentView(R.layout.activity_nav_drawer);
@@ -125,8 +131,9 @@ public class NavDrawerActivity extends BriarActivity implements
 		GridView transportsView = findViewById(R.id.transportsView);
 
 		setSupportActionBar(toolbar);
-		getSupportActionBar().setDisplayHomeAsUpEnabled(true);
-		getSupportActionBar().setHomeButtonEnabled(true);
+		ActionBar actionBar = requireNonNull(getSupportActionBar());
+		actionBar.setDisplayHomeAsUpEnabled(true);
+		actionBar.setHomeButtonEnabled(true);
 
 		drawerToggle = new ActionBarDrawerToggle(this, drawerLayout, toolbar,
 				R.string.nav_drawer_open_description,
@@ -165,7 +172,8 @@ public class NavDrawerActivity extends BriarActivity implements
 	}
 
 	@Override
-	protected void onActivityResult(int request, int result, Intent data) {
+	protected void onActivityResult(int request, int result,
+			@Nullable Intent data) {
 		super.onActivityResult(request, result, data);
 		if (request == REQUEST_PASSWORD && result == RESULT_OK) {
 			controller.shouldAskForDozeWhitelisting(this,
@@ -253,7 +261,7 @@ public class NavDrawerActivity extends BriarActivity implements
 	}
 
 	@Override
-	public void onPostCreate(Bundle savedInstanceState) {
+	public void onPostCreate(@Nullable Bundle savedInstanceState) {
 		super.onPostCreate(savedInstanceState);
 		drawerToggle.syncState();
 	}

briar-android/src/main/java/org/briarproject/briar/android/privategroup/creation/CreateGroupFragment.java

@@ -2,6 +2,7 @@ package org.briarproject.briar.android.privategroup.creation;
 
 import android.content.Context;
 import android.os.Bundle;
+import android.support.annotation.Nullable;
 import android.support.design.widget.TextInputLayout;
 import android.text.Editable;
 import android.text.TextWatcher;
@@ -12,6 +13,8 @@ import android.widget.Button;
 import android.widget.EditText;
 import android.widget.ProgressBar;
 
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.util.StringUtils;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
@@ -23,6 +26,8 @@ import static android.view.inputmethod.EditorInfo.IME_ACTION_DONE;
 import static org.briarproject.briar.android.util.UiUtils.enterPressed;
 import static org.briarproject.briar.api.privategroup.PrivateGroupConstants.MAX_GROUP_NAME_LENGTH;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public class CreateGroupFragment extends BaseFragment {
 
 	public final static String TAG = CreateGroupFragment.class.getName();
@@ -40,8 +45,13 @@ public class CreateGroupFragment extends BaseFragment {
 	}
 
 	@Override
-	public View onCreateView(LayoutInflater inflater, ViewGroup container,
-			Bundle savedInstanceState) {
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+	}
+
+	@Override
+	public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
+			@Nullable Bundle savedInstanceState) {
 
 		View v = inflater.inflate(R.layout.fragment_create_group, container,
 				false);
@@ -87,11 +97,6 @@ public class CreateGroupFragment extends BaseFragment {
 		listener.showSoftKeyboard(nameEntry);
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-	}
-
 	@Override
 	public String getUniqueTag() {
 		return TAG;

briar-android/src/main/java/org/briarproject/briar/android/privategroup/creation/CreateGroupMessageFragment.java

@@ -2,10 +2,13 @@ package org.briarproject.briar.android.privategroup.creation;
 
 import android.support.annotation.StringRes;
 
+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.sharing.BaseMessageFragment;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public class CreateGroupMessageFragment extends BaseMessageFragment {
 
 	private final static String TAG =
@@ -28,9 +31,4 @@ public class CreateGroupMessageFragment extends BaseMessageFragment {
 		return TAG;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-	}
-
 }

briar-android/src/main/java/org/briarproject/briar/android/privategroup/creation/GroupInviteFragment.java

@@ -1,6 +1,7 @@
 package org.briarproject.briar.android.privategroup.creation;
 
 import android.os.Bundle;
+import android.support.annotation.Nullable;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
@@ -13,6 +14,7 @@ import org.briarproject.briar.android.contactselection.SelectableContactItem;
 
 import javax.inject.Inject;
 
+import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 
 @MethodsNotNullByDefault
@@ -33,14 +35,14 @@ public class GroupInviteFragment extends ContactSelectorFragment {
 	}
 
 	@Override
-	public void onCreate(Bundle savedInstanceState) {
-		super.onCreate(savedInstanceState);
-		getActivity().setTitle(R.string.groups_invite_members);
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
 	}
 
 	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
+	public void onCreate(@Nullable Bundle savedInstanceState) {
+		super.onCreate(savedInstanceState);
+		requireNonNull(getActivity()).setTitle(R.string.groups_invite_members);
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/privategroup/list/GroupListFragment.java

@@ -37,6 +37,7 @@ import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import static android.support.design.widget.Snackbar.LENGTH_INDEFINITE;
+import static java.util.Objects.requireNonNull;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -57,17 +58,23 @@ public class GroupListFragment extends BaseFragment implements
 	private GroupListAdapter adapter;
 	private Snackbar snackbar;
 
+	@Override
+	public void injectFragment(ActivityComponent component) {
+		component.inject(this);
+		controller.setGroupListListener(this);
+	}
+
 	@Nullable
 	@Override
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
 
-		getActivity().setTitle(R.string.groups_button);
+		requireNonNull(getActivity()).setTitle(R.string.groups_button);
 
 		View v = inflater.inflate(R.layout.list, container, false);
 
-		adapter = new GroupListAdapter(getContext(), this);
+		adapter = new GroupListAdapter(getActivity(), this);
 		list = v.findViewById(R.id.list);
 		list.setEmptyImage(R.drawable.ic_empty_state_group_list);
 		list.setEmptyText(R.string.groups_list_empty);
@@ -79,17 +86,11 @@ public class GroupListFragment extends BaseFragment implements
 		snackbar.getView().setBackgroundResource(R.color.briar_primary);
 		snackbar.setAction(R.string.show, this);
 		snackbar.setActionTextColor(ContextCompat
-				.getColor(getContext(), R.color.briar_button_text_positive));
+				.getColor(getActivity(), R.color.briar_button_text_positive));
 
 		return v;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-		controller.setGroupListListener(this);
-	}
-
 	@Override
 	public void onStart() {
 		super.onStart();

briar-android/src/main/java/org/briarproject/briar/android/sharing/BaseMessageFragment.java

@@ -37,7 +37,7 @@ public abstract class BaseMessageFragment extends BaseFragment
 	}
 
 	@Override
-	public View onCreateView(@Nullable LayoutInflater inflater,
+	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
 

briar-android/src/main/java/org/briarproject/briar/android/sharing/ShareBlogMessageFragment.java

@@ -1,14 +1,18 @@
 package org.briarproject.briar.android.sharing;
 
 import android.os.Bundle;
+import android.support.annotation.Nullable;
 import android.support.annotation.StringRes;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
+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;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public class ShareBlogMessageFragment extends BaseMessageFragment {
 
 	public final static String TAG = ShareBlogMessageFragment.class.getName();
@@ -18,9 +22,9 @@ public class ShareBlogMessageFragment extends BaseMessageFragment {
 	}
 
 	@Override
-	public View onCreateView(LayoutInflater inflater, ViewGroup container,
-			Bundle savedInstanceState) {
-
+	public View onCreateView(LayoutInflater inflater,
+			@Nullable ViewGroup container,
+			@Nullable Bundle savedInstanceState) {
 		setTitle(R.string.blogs_sharing_share);
 		return super.onCreateView(inflater, container, savedInstanceState);
 	}
@@ -37,11 +41,6 @@ public class ShareBlogMessageFragment extends BaseMessageFragment {
 		return R.string.forum_share_message;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-	}
-
 	@Override
 	public String getUniqueTag() {
 		return TAG;

briar-android/src/main/java/org/briarproject/briar/android/sharing/ShareForumMessageFragment.java

@@ -1,14 +1,18 @@
 package org.briarproject.briar.android.sharing;
 
 import android.os.Bundle;
+import android.support.annotation.Nullable;
 import android.support.annotation.StringRes;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
+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;
 
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
 public class ShareForumMessageFragment extends BaseMessageFragment {
 
 	public final static String TAG = ShareForumMessageFragment.class.getName();
@@ -18,8 +22,9 @@ public class ShareForumMessageFragment extends BaseMessageFragment {
 	}
 
 	@Override
-	public View onCreateView(LayoutInflater inflater, ViewGroup container,
-			Bundle savedInstanceState) {
+	public View onCreateView(LayoutInflater inflater,
+			@Nullable ViewGroup container,
+			@Nullable Bundle savedInstanceState) {
 
 		setTitle(R.string.forum_share_button);
 		return super.onCreateView(inflater, container, savedInstanceState);
@@ -37,11 +42,6 @@ public class ShareForumMessageFragment extends BaseMessageFragment {
 		return R.string.forum_share_message;
 	}
 
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-	}
-
 	@Override
 	public String getUniqueTag() {
 		return TAG;