Clean up after migrating blog controllers to view model

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

@@ -13,7 +13,6 @@ import org.briarproject.briar.android.blog.BlogActivity;
 import org.briarproject.briar.android.blog.BlogFragment;
 import org.briarproject.briar.android.blog.BlogPostFragment;
 import org.briarproject.briar.android.blog.FeedFragment;
-import org.briarproject.briar.android.blog.FeedPostFragment;
 import org.briarproject.briar.android.blog.ReblogActivity;
 import org.briarproject.briar.android.blog.ReblogFragment;
 import org.briarproject.briar.android.blog.RssFeedImportActivity;
@@ -150,8 +149,6 @@ public interface ActivityComponent {
 
 	void inject(BlogPostFragment fragment);
 
-	void inject(FeedPostFragment fragment);
-
 	void inject(ReblogFragment fragment);
 
 	void inject(ReblogActivity activity);

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

@@ -1,37 +0,0 @@
-package org.briarproject.briar.android.blog;
-
-import org.briarproject.bramble.api.db.DatabaseExecutor;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.event.EventListener;
-import org.briarproject.bramble.api.identity.IdentityManager;
-import org.briarproject.bramble.api.lifecycle.LifecycleManager;
-import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
-import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.briar.android.controller.DbControllerImpl;
-import org.briarproject.briar.api.android.AndroidNotificationManager;
-import org.briarproject.briar.api.blog.BlogManager;
-
-import java.util.concurrent.Executor;
-
-@MethodsNotNullByDefault
-@ParametersNotNullByDefault
-abstract class BaseControllerImpl extends DbControllerImpl
-		implements EventListener {
-
-	protected final EventBus eventBus;
-	protected final AndroidNotificationManager notificationManager;
-	protected final IdentityManager identityManager;
-	protected final BlogManager blogManager;
-
-	BaseControllerImpl(@DatabaseExecutor Executor dbExecutor,
-			LifecycleManager lifecycleManager, EventBus eventBus,
-			AndroidNotificationManager notificationManager,
-			IdentityManager identityManager, BlogManager blogManager) {
-		super(dbExecutor, lifecycleManager);
-		this.eventBus = eventBus;
-		this.notificationManager = notificationManager;
-		this.identityManager = identityManager;
-		this.blogManager = blogManager;
-	}
-
-}

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

@@ -1,128 +0,0 @@
-package org.briarproject.briar.android.blog;
-
-import android.content.Intent;
-import android.os.Bundle;
-import android.os.Handler;
-import android.os.Looper;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.ProgressBar;
-
-import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
-import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.briar.R;
-import org.briarproject.briar.android.fragment.BaseFragment;
-import org.briarproject.briar.android.widget.LinkDialogFragment;
-
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-
-import androidx.annotation.CallSuper;
-import androidx.annotation.UiThread;
-
-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.logging.Logger.getLogger;
-import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
-import static org.briarproject.briar.android.util.UiUtils.MIN_DATE_RESOLUTION;
-
-@UiThread
-@MethodsNotNullByDefault
-@ParametersNotNullByDefault
-abstract class BasePostFragment extends BaseFragment {
-
-	static final String POST_ID = "briar.POST_ID";
-
-	private static final Logger LOG =
-			getLogger(BasePostFragment.class.getName());
-
-	private final Handler handler = new Handler(Looper.getMainLooper());
-
-	protected MessageId postId;
-	private ProgressBar progressBar;
-	private BlogPostViewHolder ui;
-	private BlogPostItem post;
-	private Runnable refresher;
-
-	@CallSuper
-	@Nullable
-	@Override
-	public View onCreateView(LayoutInflater inflater,
-			@Nullable ViewGroup container,
-			@Nullable Bundle savedInstanceState) {
-		// retrieve MessageId of blog post from arguments
-		byte[] p = requireArguments().getByteArray(POST_ID);
-		if (p == null) throw new IllegalStateException("No post ID in args");
-		postId = new MessageId(p);
-
-		View view = inflater.inflate(R.layout.fragment_blog_post, container,
-				false);
-		progressBar = view.findViewById(R.id.progressBar);
-		progressBar.setVisibility(VISIBLE);
-		ui = new BlogPostViewHolder(view, true, new OnBlogPostClickListener() {
-			@Override
-			public void onBlogPostClick(BlogPostItem post) {
-				// We're already there
-			}
-
-			@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);
-				getContext().startActivity(i);
-			}
-
-			@Override
-			public void onLinkClick(String url) {
-				LinkDialogFragment f = LinkDialogFragment.newInstance(url);
-				f.show(getParentFragmentManager(), f.getUniqueTag());
-			}
-		});
-		return view;
-	}
-
-	@CallSuper
-	@Override
-	public void onStart() {
-		super.onStart();
-		startPeriodicUpdate();
-	}
-
-	@CallSuper
-	@Override
-	public void onStop() {
-		super.onStop();
-		stopPeriodicUpdate();
-	}
-
-	@UiThread
-	protected void onBlogPostLoaded(BlogPostItem post) {
-		progressBar.setVisibility(INVISIBLE);
-		this.post = post;
-		ui.bindItem(post);
-	}
-
-	private void startPeriodicUpdate() {
-		refresher = () -> {
-			LOG.info("Updating Content...");
-			ui.updateDate(post.getTimestamp());
-			handler.postDelayed(refresher, MIN_DATE_RESOLUTION);
-		};
-		LOG.info("Adding Handler Callback");
-		handler.postDelayed(refresher, MIN_DATE_RESOLUTION);
-	}
-
-	private void stopPeriodicUpdate() {
-		if (refresher != null) {
-			LOG.info("Removing Handler Callback");
-			handler.removeCallbacks(refresher);
-		}
-	}
-
-}

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

@@ -6,7 +6,6 @@ import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.db.TransactionManager;
-import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.identity.IdentityManager;
@@ -28,13 +27,10 @@ import org.briarproject.briar.util.HtmlUtils;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
-import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
-import javax.inject.Inject;
 
 import androidx.annotation.UiThread;
 import androidx.lifecycle.LiveData;
@@ -48,27 +44,23 @@ import static org.briarproject.bramble.util.LogUtils.now;
 import static org.briarproject.briar.util.HtmlUtils.ARTICLE;
 
 @NotNullByDefault
-public class BaseViewModel extends DbViewModel implements EventListener {
+abstract class BaseViewModel extends DbViewModel implements EventListener {
 
 	private static final Logger LOG = getLogger(BaseViewModel.class.getName());
 
-	protected final TransactionManager db;
 	private final EventBus eventBus;
+	protected final TransactionManager db;
 	protected final IdentityManager identityManager;
 	protected final AndroidNotificationManager notificationManager;
 	protected final BlogManager blogManager;
 
-	private final MutableLiveData<LiveResult<List<BlogPostItem>>> blogPosts =
+	protected final MutableLiveData<LiveResult<List<BlogPostItem>>> blogPosts =
 			new MutableLiveData<>();
 
-	// TODO do we still need those caches?
+	// UI thread
-	private final Map<MessageId, String> textCache = new ConcurrentHashMap<>();
-	private final Map<MessageId, BlogPostHeader> headerCache =
-			new ConcurrentHashMap<>();
 	@Nullable
 	private Boolean postAddedWasLocal = null;
 
-	@Inject
 	BaseViewModel(Application application,
 			@DatabaseExecutor Executor dbExecutor,
 			LifecycleManager lifecycleManager,
@@ -84,7 +76,6 @@ public class BaseViewModel extends DbViewModel implements EventListener {
 		this.identityManager = identityManager;
 		this.notificationManager = notificationManager;
 		this.blogManager = blogManager;
-
 		eventBus.addListener(this);
 	}
 
@@ -94,10 +85,6 @@ public class BaseViewModel extends DbViewModel implements EventListener {
 		eventBus.removeListener(this);
 	}
 
-	@Override
-	public void eventOccurred(Event e) {
-	}
-
 	@DatabaseExecutor
 	protected List<BlogPostItem> loadBlogPosts(Transaction txn, GroupId groupId)
 			throws DbException {
@@ -108,7 +95,6 @@ public class BaseViewModel extends DbViewModel implements EventListener {
 		List<BlogPostItem> items = new ArrayList<>(headers.size());
 		start = now();
 		for (BlogPostHeader h : headers) {
-			headerCache.put(h.getId(), h);
 			BlogPostItem item = getItem(txn, h);
 			items.add(item);
 		}
@@ -135,12 +121,7 @@ public class BaseViewModel extends DbViewModel implements EventListener {
 	@DatabaseExecutor
 	private String getPostText(Transaction txn, MessageId m)
 			throws DbException {
-		String text = textCache.get(m);
+		return HtmlUtils.clean(blogManager.getPostText(txn, m), ARTICLE);
-		if (text == null) {
-			text = HtmlUtils.clean(blogManager.getPostText(txn, m), ARTICLE);
-			textCache.put(m, text);
-		}
-		return text;
 	}
 
 	LiveData<LiveResult<BlogPostItem>> loadBlogPost(GroupId g, MessageId m) {
@@ -149,7 +130,7 @@ public class BaseViewModel extends DbViewModel implements EventListener {
 		runOnDbThread(() -> {
 			try {
 				long start = now();
-				BlogPostHeader header = getPostHeader(g, m);
+				BlogPostHeader header = blogManager.getPostHeader(g, m);
 				BlogPostItem item = db.transactionWithResult(true, txn ->
 						getItem(txn, header)
 				);
@@ -163,24 +144,7 @@ public class BaseViewModel extends DbViewModel implements EventListener {
 		return result;
 	}
 
-	@DatabaseExecutor
-	private BlogPostHeader getPostHeader(GroupId g, MessageId m)
-			throws DbException {
-		BlogPostHeader header = headerCache.get(m);
-		if (header == null) {
-			header = blogManager.getPostHeader(g, m);
-			headerCache.put(m, header);
-		}
-		return header;
-	}
-
-	@UiThread
-	protected void updateBlogPosts(LiveResult<List<BlogPostItem>> posts) {
-		blogPosts.setValue(posts);
-	}
-
 	protected void onBlogPostAdded(BlogPostHeader header, boolean local) {
-		postAddedWasLocal = local;
 		runOnDbThread(() -> {
 			try {
 				db.transaction(true, txn -> {
@@ -189,6 +153,7 @@ public class BaseViewModel extends DbViewModel implements EventListener {
 						List<BlogPostItem> items = addListItem(blogPosts, item);
 						if (items != null) {
 							Collections.sort(items);
+							postAddedWasLocal = local;
 							blogPosts.setValue(new LiveResult<>(items));
 						}
 					});

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

@@ -8,7 +8,9 @@ import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 
-// This class is not thread-safe
+import javax.annotation.concurrent.NotThreadSafe;
+
+@NotThreadSafe
 class BlogCommentItem extends BlogPostItem {
 
 	private static final BlogCommentComparator COMPARATOR =

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

@@ -166,7 +166,6 @@ public class BlogFragment extends BaseFragment
 
 		if (request == REQUEST_WRITE_BLOG_POST && result == RESULT_OK) {
 			displaySnackbar(R.string.blogs_blog_post_created, true);
-			viewModel.loadBlogPosts(groupId);
 		} else if (request == REQUEST_SHARE_BLOG && result == RESULT_OK) {
 			displaySnackbar(R.string.blogs_sharing_snackbar, false);
 		}
@@ -194,7 +193,8 @@ public class BlogFragment extends BaseFragment
 
 	@Override
 	public void onBlogPostClick(BlogPostItem post) {
-		BlogPostFragment f = BlogPostFragment.newInstance(post.getId());
+		BlogPostFragment f =
+				BlogPostFragment.newInstance(groupId, post.getId());
 		showNextFragment(f);
 	}
 

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

@@ -13,11 +13,11 @@ public interface BlogModule {
 	@Binds
 	@IntoMap
 	@ViewModelKey(FeedViewModel.class)
-	abstract ViewModel bindFeedViewModel(FeedViewModel feedViewModel);
+	ViewModel bindFeedViewModel(FeedViewModel feedViewModel);
 
 	@Binds
 	@IntoMap
 	@ViewModelKey(BlogViewModel.class)
-	abstract ViewModel bindBlogViewModel(BlogViewModel blogViewModel);
+	ViewModel bindBlogViewModel(BlogViewModel blogViewModel);
 
 }

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

@@ -1,39 +1,68 @@
 package org.briarproject.briar.android.blog;
 
+import android.content.Intent;
 import android.os.Bundle;
+import android.os.Handler;
+import android.os.Looper;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.ProgressBar;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
+import org.briarproject.briar.android.fragment.BaseFragment;
+import org.briarproject.briar.android.widget.LinkDialogFragment;
+
+import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.annotation.CallSuper;
 import androidx.annotation.UiThread;
+import androidx.lifecycle.LifecycleOwner;
 import androidx.lifecycle.ViewModelProvider;
 
+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;
+
 @UiThread
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public class BlogPostFragment extends BasePostFragment {
+public class BlogPostFragment extends BaseFragment
+		implements OnBlogPostClickListener {
 
 	private static final String TAG = BlogPostFragment.class.getName();
+	private static final Logger LOG = getLogger(TAG);
+
+	static final String POST_ID = "briar.POST_ID";
+
+	protected BlogViewModel viewModel;
+	private final Handler handler = new Handler(Looper.getMainLooper());
+
+	private ProgressBar progressBar;
+	private BlogPostViewHolder ui;
+	private BlogPostItem post;
+	private Runnable refresher;
 
 	@Inject
 	ViewModelProvider.Factory viewModelFactory;
 
-	private BlogViewModel viewModel;
+	static BlogPostFragment newInstance(GroupId blogId, MessageId postId) {
-
-	static BlogPostFragment newInstance(MessageId postId) {
 		BlogPostFragment f = new BlogPostFragment();
-
 		Bundle bundle = new Bundle();
+		bundle.putByteArray(GROUP_ID, blogId.getBytes());
 		bundle.putByteArray(POST_ID, postId.getBytes());
-
 		f.setArguments(bundle);
 		return f;
 	}
@@ -45,22 +74,89 @@ public class BlogPostFragment extends BasePostFragment {
 				.get(BlogViewModel.class);
 	}
 
-	@Override
-	public String getUniqueTag() {
-		return TAG;
-	}
-
 	@Nullable
 	@Override
 	public View onCreateView(LayoutInflater inflater,
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
-		View v = super.onCreateView(inflater, container, savedInstanceState);
+		Bundle args = requireArguments();
-		viewModel.loadBlogPost(postId).observe(getViewLifecycleOwner(), res ->
+		GroupId groupId =
-				res.onError(this::handleException)
+				new GroupId(requireNonNull(args.getByteArray(GROUP_ID)));
+		MessageId postId = new MessageId(args.getByteArray(POST_ID));
+
+		View view = inflater.inflate(R.layout.fragment_blog_post, container,
+				false);
+		progressBar = view.findViewById(R.id.progressBar);
+		progressBar.setVisibility(VISIBLE);
+		ui = new BlogPostViewHolder(view, true, this);
+		LifecycleOwner owner = getViewLifecycleOwner();
+		viewModel.loadBlogPost(groupId, postId).observe(owner, result ->
+				result.onError(this::handleException)
 						.onSuccess(this::onBlogPostLoaded)
 		);
-		return v;
+		return view;
+	}
+
+	@CallSuper
+	@Override
+	public void onStart() {
+		super.onStart();
+		startPeriodicUpdate();
+	}
+
+	@CallSuper
+	@Override
+	public void onStop() {
+		super.onStop();
+		stopPeriodicUpdate();
+	}
+
+	@UiThread
+	private void onBlogPostLoaded(BlogPostItem post) {
+		progressBar.setVisibility(INVISIBLE);
+		this.post = post;
+		ui.bindItem(post);
+	}
+
+	@Override
+	public void onBlogPostClick(BlogPostItem post) {
+		// We're already there
+	}
+
+	@Override
+	public void onAuthorClick(BlogPostItem post) {
+		Intent i = new Intent(requireContext(), BlogActivity.class);
+		i.putExtra(GROUP_ID, post.getGroupId().getBytes());
+		i.setFlags(FLAG_ACTIVITY_CLEAR_TOP);
+		getContext().startActivity(i);
+	}
+
+	@Override
+	public void onLinkClick(String url) {
+		LinkDialogFragment f = LinkDialogFragment.newInstance(url);
+		f.show(getParentFragmentManager(), f.getUniqueTag());
+	}
+
+	private void startPeriodicUpdate() {
+		refresher = () -> {
+			LOG.info("Updating Content...");
+			ui.updateDate(post.getTimestamp());
+			handler.postDelayed(refresher, MIN_DATE_RESOLUTION);
+		};
+		LOG.info("Adding Handler Callback");
+		handler.postDelayed(refresher, MIN_DATE_RESOLUTION);
+	}
+
+	private void stopPeriodicUpdate() {
+		if (refresher != null) {
+			LOG.info("Removing Handler Callback");
+			handler.removeCallbacks(refresher);
+		}
+	}
+
+	@Override
+	public String getUniqueTag() {
+		return TAG;
 	}
 
 }

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

@@ -17,7 +17,7 @@ public class BlogPostItem implements Comparable<BlogPostItem> {
 	private final BlogPostHeader header;
 	@Nullable
 	protected String text;
-	private boolean read;
+	private final boolean read;
 
 	BlogPostItem(BlogPostHeader header, @Nullable String text) {
 		this.header = header;

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

@@ -25,11 +25,14 @@ import androidx.recyclerview.widget.RecyclerView;
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 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.android.blog.BlogPostFragment.POST_ID;
 import static org.briarproject.briar.android.util.UiUtils.TEASER_LENGTH;
 import static org.briarproject.briar.android.util.UiUtils.getSpanned;
 import static org.briarproject.briar.android.util.UiUtils.getTeaser;
 import static org.briarproject.briar.android.util.UiUtils.makeLinksClickable;
+import static org.briarproject.briar.android.view.AuthorView.COMMENTER;
+import static org.briarproject.briar.android.view.AuthorView.REBLOGGER;
+import static org.briarproject.briar.android.view.AuthorView.RSS_FEED_REBLOGGED;
 import static org.briarproject.briar.api.blog.MessageType.POST;
 
 @UiThread
@@ -138,17 +141,16 @@ class BlogPostViewHolder extends RecyclerView.ViewHolder {
 			reblogger.setAuthorClickable(v -> listener.onAuthorClick(item));
 		}
 		reblogger.setVisibility(VISIBLE);
-		reblogger.setPersona(AuthorView.REBLOGGER);
+		reblogger.setPersona(REBLOGGER);
 
 		author.setPersona(item.getHeader().getRootPost().isRssFeed() ?
-				AuthorView.RSS_FEED_REBLOGGED :
+				RSS_FEED_REBLOGGED : COMMENTER);
-				AuthorView.COMMENTER);
 
 		// comments
+		// TODO use nested RecyclerView instead like we do for Image Attachments
 		for (BlogCommentHeader c : item.getComments()) {
-			View v = LayoutInflater.from(ctx)
+			View v = LayoutInflater.from(ctx).inflate(
-					.inflate(R.layout.list_item_blog_comment,
+					R.layout.list_item_blog_comment, commentContainer, false);
-							commentContainer, false);
 
 			AuthorView author = v.findViewById(R.id.authorView);
 			TextView text = v.findViewById(R.id.textView);

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

@@ -148,8 +148,8 @@ class BlogViewModel extends BaseViewModel {
 		notificationManager.unblockNotification(groupId);
 	}
 
-	void loadBlogPosts(GroupId groupId) {
+	private void loadBlogPosts(GroupId groupId) {
-		loadList(txn -> loadBlogPosts(txn, groupId), this::updateBlogPosts);
+		loadList(txn -> loadBlogPosts(txn, groupId), blogPosts::setValue);
 	}
 
 	private void loadSharingContacts(GroupId groupId) {

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

@@ -62,9 +62,6 @@ public class FeedFragment extends BaseFragment
 		component.inject(this);
 		viewModel = new ViewModelProvider(this, viewModelFactory)
 				.get(FeedViewModel.class);
-		// TODO ideally we only do this once when the ViewModel gets created
-		viewModel.loadPersonalBlog();
-		viewModel.loadAllBlogPosts();
 	}
 
 	@Nullable
@@ -154,8 +151,8 @@ public class FeedFragment extends BaseFragment
 
 	@Override
 	public void onBlogPostClick(BlogPostItem post) {
-		FeedPostFragment f =
+		BaseFragment f =
-				FeedPostFragment.newInstance(post.getGroupId(), post.getId());
+				BlogPostFragment.newInstance(post.getGroupId(), post.getId());
 		showNextFragment(f);
 	}
 

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

@@ -1,73 +0,0 @@
-package org.briarproject.briar.android.blog;
-
-import android.os.Bundle;
-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.bramble.api.sync.GroupId;
-import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.briar.android.activity.ActivityComponent;
-
-import javax.annotation.Nullable;
-import javax.inject.Inject;
-
-import androidx.annotation.UiThread;
-import androidx.lifecycle.ViewModelProvider;
-
-import static java.util.Objects.requireNonNull;
-import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
-
-@UiThread
-@MethodsNotNullByDefault
-@ParametersNotNullByDefault
-public class FeedPostFragment extends BasePostFragment {
-
-	private static final String TAG = FeedPostFragment.class.getName();
-
-	@Inject
-	ViewModelProvider.Factory viewModelFactory;
-
-	private FeedViewModel viewModel;
-
-	static FeedPostFragment newInstance(GroupId blogId, MessageId postId) {
-		FeedPostFragment f = new FeedPostFragment();
-		Bundle bundle = new Bundle();
-		bundle.putByteArray(GROUP_ID, blogId.getBytes());
-		bundle.putByteArray(POST_ID, postId.getBytes());
-		f.setArguments(bundle);
-		return f;
-	}
-
-	@Override
-	public void injectFragment(ActivityComponent component) {
-		component.inject(this);
-		viewModel = new ViewModelProvider(requireActivity(), viewModelFactory)
-				.get(FeedViewModel.class);
-	}
-
-	@Nullable
-	@Override
-	public View onCreateView(LayoutInflater inflater,
-			@Nullable ViewGroup container,
-			@Nullable Bundle savedInstanceState) {
-		Bundle args = requireArguments();
-		GroupId groupId =
-				new GroupId(requireNonNull(args.getByteArray(GROUP_ID)));
-		MessageId postId =
-				new MessageId(requireNonNull(args.getByteArray(POST_ID)));
-		viewModel.loadBlogPost(groupId, postId).observe(getViewLifecycleOwner(),
-				result -> result.onError(this::handleException)
-						.onSuccess(this::onBlogPostLoaded)
-		);
-		return super.onCreateView(inflater, container, savedInstanceState);
-	}
-
-	@Override
-	public String getUniqueTag() {
-		return TAG;
-	}
-
-}

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

@@ -17,6 +17,7 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.event.GroupAddedEvent;
 import org.briarproject.bramble.api.sync.event.GroupRemovedEvent;
 import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.briar.android.viewmodel.LiveResult;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.blog.Blog;
 import org.briarproject.briar.api.blog.BlogManager;
@@ -59,6 +60,8 @@ class FeedViewModel extends BaseViewModel {
 			BlogManager blogManager) {
 		super(application, dbExecutor, lifecycleManager, db, androidExecutor,
 				eventBus, identityManager, notificationManager, blogManager);
+		loadPersonalBlog();
+		loadAllBlogPosts();
 	}
 
 	@Override
@@ -71,13 +74,15 @@ class FeedViewModel extends BaseViewModel {
 			GroupAddedEvent g = (GroupAddedEvent) e;
 			if (g.getGroup().getClientId().equals(CLIENT_ID)) {
 				LOG.info("Blog added");
-				loadAllBlogPosts();
+				// TODO how can this even happen?
+				//  added RSS feeds should trigger BlogPostAddedEvent, no?
+				onBlogAdded(g.getGroup().getId());
 			}
 		} else if (e instanceof GroupRemovedEvent) {
 			GroupRemovedEvent g = (GroupRemovedEvent) e;
 			if (g.getGroup().getClientId().equals(CLIENT_ID)) {
 				LOG.info("Blog removed");
-				loadAllBlogPosts();
+				onBlogRemoved(g.getGroup().getId());
 			}
 		}
 	}
@@ -94,7 +99,7 @@ class FeedViewModel extends BaseViewModel {
 		notificationManager.unblockAllBlogPostNotifications();
 	}
 
-	void loadPersonalBlog() {
+	private void loadPersonalBlog() {
 		runOnDbThread(() -> {
 			try {
 				long start = now();
@@ -112,8 +117,8 @@ class FeedViewModel extends BaseViewModel {
 		return personalBlog;
 	}
 
-	void loadAllBlogPosts() {
+	private void loadAllBlogPosts() {
-		loadList(this::loadAllBlogPosts, this::updateBlogPosts);
+		loadList(this::loadAllBlogPosts, blogPosts::setValue);
 	}
 
 	@DatabaseExecutor
@@ -133,4 +138,30 @@ class FeedViewModel extends BaseViewModel {
 		return posts;
 	}
 
+	private void onBlogAdded(GroupId g) {
+		runOnDbThread(() -> {
+			try {
+				db.transaction(true, txn -> {
+					List<BlogPostItem> posts = loadBlogPosts(txn, g);
+					txn.attach(() -> {
+						List<BlogPostItem> items =
+								addListItems(blogPosts, posts);
+						if (items != null) {
+							Collections.sort(items);
+							blogPosts.setValue(new LiveResult<>(items));
+						}
+					});
+				});
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+			}
+		});
+	}
+
+	private void onBlogRemoved(GroupId g) {
+		removeAndUpdateListItems(blogPosts, item ->
+				item.getGroupId().equals(g)
+		);
+	}
+
 }

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

@@ -11,7 +11,7 @@ import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BriarActivity;
 import org.briarproject.briar.android.fragment.BaseFragment.BaseFragmentListener;
 
-import static org.briarproject.briar.android.blog.BasePostFragment.POST_ID;
+import static org.briarproject.briar.android.blog.BlogPostFragment.POST_ID;
 
 public class ReblogActivity extends BriarActivity implements
 		BaseFragmentListener {
@@ -39,13 +39,11 @@ public class ReblogActivity extends BriarActivity implements
 
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item) {
-		switch (item.getItemId()) {
+		if (item.getItemId() == android.R.id.home) {
-			case android.R.id.home:
+			onBackPressed();
-				onBackPressed();
+			return true;
-				return true;
-			default:
-				return super.onOptionsItemSelected(item);
 		}
+		return super.onOptionsItemSelected(item);
 	}
 
 	@Override

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

@@ -33,7 +33,7 @@ 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.android.blog.BlogPostFragment.POST_ID;
 import static org.briarproject.briar.api.blog.BlogConstants.MAX_BLOG_POST_TEXT_LENGTH;
 
 @MethodsNotNullByDefault
@@ -45,7 +45,7 @@ public class ReblogFragment extends BaseFragment implements SendListener {
 	@Inject
 	ViewModelProvider.Factory viewModelFactory;
 
-	private FeedViewModel viewModel;
+	private BlogViewModel viewModel;
 	private ViewHolder ui;
 	private BlogPostItem item;
 
@@ -69,7 +69,7 @@ public class ReblogFragment extends BaseFragment implements SendListener {
 	public void injectFragment(ActivityComponent component) {
 		component.inject(this);
 		viewModel = new ViewModelProvider(requireActivity(), viewModelFactory)
-				.get(FeedViewModel.class);
+				.get(BlogViewModel.class);
 	}
 
 	@Override
@@ -131,7 +131,7 @@ public class ReblogFragment extends BaseFragment implements SendListener {
 		ui.input.setVisibility(VISIBLE);
 	}
 
-	private class ViewHolder {
+	private class ViewHolder implements OnBlogPostClickListener {
 
 		private final ScrollView scrollView;
 		private final ProgressBar progressBar;
@@ -142,24 +142,25 @@ public class ReblogFragment extends BaseFragment implements SendListener {
 			scrollView = v.findViewById(R.id.scrollView);
 			progressBar = v.findViewById(R.id.progressBar);
 			post = new BlogPostViewHolder(v.findViewById(R.id.postLayout),
-					true, new OnBlogPostClickListener() {
+					true, this);
-				@Override
-				public void onBlogPostClick(BlogPostItem post) {
-					// do nothing
-				}
-
-				@Override
-				public void onAuthorClick(BlogPostItem post) {
-					// probably don't want to allow author clicks here
-				}
-
-				@Override
-				public void onLinkClick(String url) {
-					LinkDialogFragment f = LinkDialogFragment.newInstance(url);
-					f.show(getParentFragmentManager(), f.getUniqueTag());
-				}
-			});
 			input = v.findViewById(R.id.inputText);
 		}
+
+		@Override
+		public void onBlogPostClick(BlogPostItem post) {
+			// do nothing
+		}
+
+		@Override
+		public void onAuthorClick(BlogPostItem post) {
+			// probably don't want to allow author clicks here
+		}
+
+		@Override
+		public void onLinkClick(String url) {
+			LinkDialogFragment f = LinkDialogFragment.newInstance(url);
+			f.show(getParentFragmentManager(), f.getUniqueTag());
+		}
 	}
+
 }

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

@@ -156,11 +156,9 @@ class ForumListViewModel extends DbViewModel implements EventListener {
 
 	@UiThread
 	private void onGroupRemoved(GroupId groupId) {
-		List<ForumListItem> list = removeListItems(forumItems, i ->
+		removeAndUpdateListItems(forumItems, i ->
 				i.getForum().getId().equals(groupId)
 		);
-		if (list == null) return;
-		forumItems.setValue(new LiveResult<>(list));
 	}
 
 	void loadForumInvitations() {

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

@@ -193,10 +193,7 @@ class GroupListViewModel extends DbViewModel implements EventListener {
 
 	@UiThread
 	private void onGroupRemoved(GroupId groupId) {
-		List<GroupItem> list =
+		removeAndUpdateListItems(groupItems, i -> i.getId().equals(groupId));
-				removeListItems(groupItems, i -> i.getId().equals(groupId));
-		if (list == null) return;
-		groupItems.setValue(new LiveResult<>(list));
 	}
 
 	void removeGroup(GroupId g) {

briar-android/src/main/java/org/briarproject/briar/android/viewmodel/DbViewModel.java

@@ -13,6 +13,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.system.AndroidExecutor;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 import java.util.ListIterator;
 import java.util.concurrent.Executor;
@@ -27,6 +28,7 @@ import androidx.arch.core.util.Function;
 import androidx.core.util.Consumer;
 import androidx.lifecycle.AndroidViewModel;
 import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
 import androidx.recyclerview.widget.RecyclerView;
 
 import static java.util.logging.Level.WARNING;
@@ -153,13 +155,33 @@ public abstract class DbViewModel extends AndroidViewModel {
 	 * </ul>
 	 */
 	@Nullable
-	protected <T> List<T> addListItem(LiveData<LiveResult<List<T>>> liveData, T item) {
+	protected <T> List<T> addListItem(LiveData<LiveResult<List<T>>> liveData,
+			T item) {
 		List<T> items = getListCopy(liveData);
 		if (items == null) return null;
 		items.add(item);
 		return items;
 	}
 
+	/**
+	 * Creates a copy of the list available in the given LiveData
+	 * and adds the given items to the copy.
+	 *
+	 * @return a copy of the list in the LiveData with items added or null when
+	 * <ul>
+	 * <li> LiveData does not have a value
+	 * <li> LiveResult in the LiveData has an error
+	 * </ul>
+	 */
+	@Nullable
+	protected <T> List<T> addListItems(LiveData<LiveResult<List<T>>> liveData,
+			Collection<T> items) {
+		List<T> copiedItems = getListCopy(liveData);
+		if (copiedItems == null) return null;
+		copiedItems.addAll(items);
+		return copiedItems;
+	}
+
 	/**
 	 * Creates a copy of the list available in the given LiveData
 	 * and replaces items where the given test function returns true.
@@ -221,6 +243,25 @@ public abstract class DbViewModel extends AndroidViewModel {
 		return changed ? items : null;
 	}
 
+	/**
+	 * Updates the given LiveData with a copy of its list
+	 * with the items removed where the given test function returns true.
+	 * <p>
+	 * Nothing is updated, if the
+	 * <ul>
+	 * <li> LiveData does not have a value
+	 * <li> LiveResult in the LiveData has an error
+	 * <li> test function did return false for all items in the list
+	 * </ul>
+	 */
+	@UiThread
+	protected <T> void removeAndUpdateListItems(
+			MutableLiveData<LiveResult<List<T>>> liveData,
+			Function<T, Boolean> test) {
+		List<T> list = removeListItems(liveData, test);
+		if (list != null) liveData.setValue(new LiveResult<>(list));
+	}
+
 	/**
 	 * Retrieves a copy of the list of items from the given LiveData
 	 * or null if it is not available.