Implement live updates for microblog posts

Introduce listeners to receive and retract microblog posts in real-time. This allows the post view to update automatically when new posts are received or existing ones are retracted, without requiring a manual refresh.

Key changes include:
- Add `OnPostReceived` and `OnPostRetracted` listeners in `XmppConnectionService`.
- Parse incoming microblog posts from both IQ stanzas and pubsub event messages.
- Update the `PostsActivity` to reflect new and retracted posts instantly.
- Pass the `postId` on post retraction for more specific UI updates.
- Announce support for the `urn:xmpp:microblog:0` namespace.

src/main/java/eu/siacs/conversations/generator/AbstractGenerator.java

@@ -116,7 +116,8 @@ public abstract class AbstractGenerator {
         final ArrayList<String> features = new ArrayList<>(Arrays.asList(STATIC_FEATURES));
         features.add("http://jabber.org/protocol/xhtml-im");
         features.add("urn:xmpp:bob");
-        features.add(Namespace.PUBSUB_SOCIAL_FEED);
+        features.add("urn:xmpp:microblog:0");
+        features.add("urn:xmpp:microblog:0+notify");
         features.add(Namespace.PUBSUB_STORIES);
         features.add(Namespace.PUBSUB_STORIES + "+notify");
         if (Config.MESSAGE_DISPLAYED_SYNCHRONIZATION) {

src/main/java/eu/siacs/conversations/generator/IqGenerator.java

@@ -859,9 +859,29 @@ public class IqGenerator extends AbstractGenerator {
         final String now = AbstractGenerator.getTimestamp(System.currentTimeMillis());
         entry.addChild("published").setContent(now);
         entry.addChild("updated").setContent(now);
+        // create a child node for the node
+        pubsub.addChild("create").setAttribute("node", "urn:xmpp:microblog:0");
+        final Element configure = pubsub.addChild("configure");
+        // Correctly use the 'pubsub#node_config' namespace
+        final Data data = Data.create("http://jabber.org/protocol/pubsub#node_config", defaultPostConfiguration());
+        configure.addChild(data);
         return iq;
     }
 
+    public static Bundle defaultPostConfiguration() {
+        Bundle options = new Bundle();
+        options.putString("pubsub#node_type", "leaf");
+        options.putString("pubsub#type", "urn:xmpp:microblog:0");
+        options.putString("pubsub#access_model", "roster");
+        options.putString("pubsub#item_expire", "86400");
+        options.putString("pubsub#persist_items", "1");
+        options.putString("pubsub#max_items", "120");
+        options.putString("pubsub#notify_retract", "1");
+        options.putString("pubsub#send_last_published_item", "on_sub");
+        options.putString("pubsub#publish_model", "publishers");
+        return options;
+    }
+
     public Iq publishComment(final Account account, final String node, final String title, final String inReplyToId) {
         final Iq iq = new Iq(Iq.Type.SET);
         iq.setTo(account.getJid().asBareJid());

src/main/java/eu/siacs/conversations/parser/IqParser.java

@@ -10,6 +10,7 @@ import eu.siacs.conversations.Config;
 import eu.siacs.conversations.crypto.axolotl.AxolotlService;
 import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.entities.Contact;
+import eu.siacs.conversations.entities.Post;
 import eu.siacs.conversations.entities.Room;
 import eu.siacs.conversations.entities.Story;
 import eu.siacs.conversations.services.XmppConnectionService;
@@ -456,6 +457,29 @@ public class IqParser extends AbstractParser implements Consumer<Iq> {
                             }
                         }
                     }
+                } else if ("urn:xmpp:microblog:0".equals(node)) {
+                    for (Element item : items.getChildren()) {
+                        if ("item".equals(item.getName())) {
+                            Element entry = item.findChild("entry", Namespace.ATOM);
+                            if (entry != null) {
+                                try {
+                                    Post post = Post.fromElement(entry);
+                                    mXmppConnectionService.onPostReceived(post, account);
+                                    if (mXmppConnectionService.getOnPostReceivedListener() != null) {
+                                        mXmppConnectionService.getOnPostReceivedListener().onPostReceived(post);
+                                    }
+                                } catch (Exception e) {
+                                    Log.e(
+                                            Config.LOGTAG,
+                                            "error creating post from pubsub item in iq",
+                                            e);
+                                }
+                            }
+                        } else if (item.getName().equals("retract")) {
+                            final String postId = item.getAttribute("id");
+                            mXmppConnectionService.onPostRetracted(postId);
+                        }
+                    }
                 }
             }
         } else if ((packet.hasChild("block", Namespace.BLOCKING)

src/main/java/eu/siacs/conversations/parser/MessageParser.java

@@ -35,6 +35,7 @@ import java.util.function.Consumer;
 import java.util.stream.Collectors;
 
 import eu.siacs.conversations.crypto.OtrService;
+import eu.siacs.conversations.entities.Post;
 import eu.siacs.conversations.entities.Presence;
 import eu.siacs.conversations.entities.ServiceDiscoveryResult;
 import eu.siacs.conversations.entities.Story;
@@ -1756,8 +1757,29 @@ public class MessageParser extends AbstractParser
         final Element event =
                 original.findChild("event", "http://jabber.org/protocol/pubsub#event");
         if (event != null && Jid.Invalid.hasValidFrom(original) && original.getFrom().isBareJid()) {
-            if (event.hasChild("items")) {
-                parseEvent(event, original.getFrom(), account);
+            final Element items = event.findChild("items");
+            if (items != null) {
+                final String node = items.getAttribute("node");
+                if ("urn:xmpp:microblog:0".equals(node)) {
+                    for (Element item : items.getChildren()) {
+                        if ("item".equals(item.getName())) {
+                            Element entry = item.findChild("entry", Namespace.ATOM);
+                            if (entry != null) {
+                                try {
+                                    Post post = Post.fromElement(entry);
+                                    mXmppConnectionService.databaseBackend.createPost(post, account);
+                                    if (mXmppConnectionService.getOnPostReceivedListener() != null) {
+                                        mXmppConnectionService.getOnPostReceivedListener().onPostReceived(post);
+                                    }
+                                } catch (Exception e) {
+                                    Log.d(Config.LOGTAG, "error creating post from pubsub item", e);
+                                }
+                            }
+                        }
+                    }
+                } else {
+                    parseEvent(event, original.getFrom(), account);
+                }
             } else if (event.hasChild("delete")) {
                 parseDeleteEvent(event, original.getFrom(), account);
             } else if (event.hasChild("purge")) {

src/main/java/eu/siacs/conversations/services/XmppConnectionService.java

@@ -126,6 +126,7 @@ import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
 
 import eu.siacs.conversations.Conversations;
+import eu.siacs.conversations.entities.Post;
 import eu.siacs.conversations.entities.Story;
 import eu.siacs.conversations.entities.StubConversation;
 import eu.siacs.conversations.utils.TranscoderStrategies;
@@ -8227,7 +8228,7 @@ public class XmppConnectionService extends Service {
         sendIqPacket(account, request, response -> {
             if (response.getType() == Iq.Type.RESULT) {
                 if (callback != null) {
-                    callback.onPostRetracted();
+                    callback.onPostRetracted(id);
                 }
             } else {
                 if (callback != null) {
@@ -8242,8 +8243,52 @@ public class XmppConnectionService extends Service {
         void onPostPublishFailed();
     }
 
+    public interface OnPostReceived {
+        void onPostReceived(Post post);
+    }
+
+    private OnPostReceived mOnPostReceivedListener;
+
+    public void setOnPostReceivedListener(OnPostReceived listener) {
+        this.mOnPostReceivedListener = listener;
+    }
+
+    public OnPostReceived getOnPostReceivedListener() {
+        return this.mOnPostReceivedListener;
+    }
+
+    public void onPostReceived(Post post, Account account) {
+        if (post == null || account == null) {
+            return;
+        }
+        databaseBackend.createPost(post, account);
+        if (mOnPostReceivedListener != null) {
+            mOnPostReceivedListener.onPostReceived(post);
+        }
+    }
+
     public interface OnPostRetracted {
-        void onPostRetracted();
+        void onPostRetracted(String postId);
         void onPostRetractionFailed();
     }
+
+    private OnPostRetracted mOnPostRetractedListener;
+
+    public void setOnPostRetractedListener(OnPostRetracted listener) {
+        this.mOnPostRetractedListener = listener;
+    }
+
+    public OnPostRetracted getOnPostRetractedListener() {
+        return this.mOnPostRetractedListener;
+    }
+
+    public void onPostRetracted(String postId) {
+        if (postId == null) {
+            return;
+        }
+        databaseBackend.deletePost(postId);
+        if (mOnPostRetractedListener != null) {
+            mOnPostRetractedListener.onPostRetracted(postId);
+        }
+    }
 }

src/main/java/eu/siacs/conversations/ui/CreatePostActivity.java

@@ -34,6 +34,7 @@ import eu.siacs.conversations.R;
 import eu.siacs.conversations.databinding.ActivityCreatePostBinding;
 import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.services.XmppConnectionService;
+import eu.siacs.conversations.xml.Namespace;
 
 public class CreatePostActivity extends XmppActivity {
 

src/main/java/eu/siacs/conversations/ui/PostsActivity.java

@@ -17,6 +17,9 @@ import androidx.recyclerview.widget.LinearLayoutManager;
 
 import com.google.android.material.bottomnavigation.BottomNavigationView;
 
+import org.xmlpull.v1.XmlPullParserException;
+
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -34,7 +37,7 @@ import eu.siacs.conversations.xml.Namespace;
 import eu.siacs.conversations.xml.XmlReader;
 import eu.siacs.conversations.xmpp.Jid;
 
-public class PostsActivity extends XmppActivity {
+public class PostsActivity extends XmppActivity implements XmppConnectionService.OnPostReceived, XmppConnectionService.OnPostRetracted {
 
     private ActivityPostsBinding binding;
     private PostsAdapter postsAdapter;
@@ -44,6 +47,7 @@ public class PostsActivity extends XmppActivity {
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         binding = DataBindingUtil.setContentView(this, R.layout.activity_posts);
+        Activities.setStatusAndNavigationBarColors(this, binding.getRoot());
         setSupportActionBar(binding.toolbar);
         configureActionBar(getSupportActionBar());
 
@@ -93,6 +97,10 @@ public class PostsActivity extends XmppActivity {
     @Override
     public void onStart() {
         super.onStart();
+        if (xmppConnectionService != null) {
+            xmppConnectionService.setOnPostReceivedListener(this);
+            xmppConnectionService.setOnPostRetractedListener(this);
+        }
         if (postList.isEmpty()) {
             loadPosts();
         }
@@ -106,11 +114,40 @@ public class PostsActivity extends XmppActivity {
         }
     }
 
+    @Override
+    public void onStop() {
+        super.onStop();
+        if (xmppConnectionService != null) {
+            xmppConnectionService.setOnPostReceivedListener(null);
+            xmppConnectionService.setOnPostRetractedListener(null);
+        }
+    }
+
     @Override
     public void onBackendConnected() {
+        if (xmppConnectionService != null) {
+            xmppConnectionService.setOnPostReceivedListener(this);
+            xmppConnectionService.setOnPostRetractedListener(this);
+        }
         refreshUiReal();
     }
 
+    @Override
+    public void onPostReceived(final Post post) {
+        runOnUiThread(() -> {
+            if (post != null) {
+                postList.add(0, post);
+                java.util.Collections.sort(postList, (p1, p2) -> {
+                    if (p1.getPublished() == null && p2.getPublished() == null) return 0;
+                    if (p1.getPublished() == null) return 1;
+                    if (p2.getPublished() == null) return -1;
+                    return p2.getPublished().compareTo(p1.getPublished());
+                });
+                postsAdapter.notifyDataSetChanged();
+            }
+        });
+    }
+
     @Override
     protected void refreshUiReal() {
         if (postList.isEmpty()) {
@@ -262,4 +299,21 @@ public class PostsActivity extends XmppActivity {
 
         super.onBackPressed();
     }
-}
+    @Override
+    public void onPostRetracted(String postId) {
+        runOnUiThread(() -> {
+            for (int i = 0; i < postList.size(); ++i) {
+                if (postList.get(i).getId().equals(postId)) {
+                    postList.remove(i);
+                    postsAdapter.notifyItemRemoved(i);
+                    break;
+                }
+            }
+        });
+    }
+
+    @Override
+    public void onPostRetractionFailed() {
+        runOnUiThread(() -> Toast.makeText(this, R.string.error_retract_post, Toast.LENGTH_SHORT).show());
+    }
+}

src/main/java/eu/siacs/conversations/ui/adapter/PostsAdapter.java

@@ -258,10 +258,11 @@ public class PostsAdapter extends RecyclerView.Adapter<PostsAdapter.PostViewHold
                                 .setPositiveButton(R.string.retract, (dialog, which) -> {
                                     mActivity.xmppConnectionService.retractPost(ownAccount, "urn:xmpp:microblog:0", post.getId(),
                                             new XmppConnectionService.OnPostRetracted() {
+
                                                 @Override
-                                                public void onPostRetracted() {
+                                                public void onPostRetracted(String postId) {
                                                     mActivity.runOnUiThread(() -> {
-                                                        mActivity.xmppConnectionService.databaseBackend.deletePost(post.getId());
+                                                        mActivity.xmppConnectionService.databaseBackend.deletePost(postId);
                                                         int pos = getAdapterPosition();
                                                         if (pos != RecyclerView.NO_POSITION) {
                                                             posts.remove(pos);