rudimentary MessageAdapter

app/src/androidTest/java/im/conversations/android/xmpp/MessageTransformationTest.java

@@ -59,7 +59,7 @@ public class MessageTransformationTest extends BaseTransformationTest {
                         originalMessage.getFrom().asBareJid(),
                         null));
 
-        final var messages = database.messageDao().getMessages(1L);
+        final var messages = database.messageDao().getMessagesForTesting(1L);
         Assert.assertEquals(1, messages.size());
         final var message = Iterables.getOnlyElement(messages);
         final var onlyContent = Iterables.getOnlyElement(message.contents);
@@ -103,7 +103,7 @@ public class MessageTransformationTest extends BaseTransformationTest {
                 MessageTransformation.of(
                         reactionC, Instant.now(), REMOTE, "stanza-d", null, "id-user-d"));
 
-        final var messages = database.messageDao().getMessages(1L);
+        final var messages = database.messageDao().getMessagesForTesting(1L);
         Assert.assertEquals(1, messages.size());
         final var dbMessage = Iterables.getOnlyElement(messages);
         Assert.assertEquals(4, dbMessage.reactions.size());
@@ -136,7 +136,7 @@ public class MessageTransformationTest extends BaseTransformationTest {
                         null));
 
         // the correction should not show up as a message
-        Assert.assertEquals(0, database.messageDao().getMessages(1L).size());
+        Assert.assertEquals(0, database.messageDao().getMessagesForTesting(1L).size());
 
         final var messageWithTypo = new Message();
         messageWithTypo.setId("1");
@@ -153,7 +153,7 @@ public class MessageTransformationTest extends BaseTransformationTest {
                         messageWithTypo.getFrom().asBareJid(),
                         null));
 
-        final var messages = database.messageDao().getMessages(1L);
+        final var messages = database.messageDao().getMessagesForTesting(1L);
 
         Assert.assertEquals(1, messages.size());
 
@@ -181,7 +181,7 @@ public class MessageTransformationTest extends BaseTransformationTest {
                         messageWithTypo.getFrom().asBareJid(),
                         null));
 
-        Assert.assertEquals(1, database.messageDao().getMessages(1L).size());
+        Assert.assertEquals(1, database.messageDao().getMessagesForTesting(1L).size());
 
         final var messageCorrection = new Message();
         messageCorrection.setId("2");
@@ -199,7 +199,7 @@ public class MessageTransformationTest extends BaseTransformationTest {
                         messageCorrection.getFrom().asBareJid(),
                         null));
 
-        final var messages = database.messageDao().getMessages(1L);
+        final var messages = database.messageDao().getMessagesForTesting(1L);
 
         Assert.assertEquals(1, messages.size());
 
@@ -233,7 +233,7 @@ public class MessageTransformationTest extends BaseTransformationTest {
                 MessageTransformation.of(
                         reactionB, Instant.now(), REMOTE, "stanza-c", null, "id-user-b"));
 
-        final var messages = database.messageDao().getMessages(1L);
+        final var messages = database.messageDao().getMessagesForTesting(1L);
         Assert.assertEquals(1, messages.size());
         final var dbMessage = Iterables.getOnlyElement(messages);
         Assert.assertEquals(1, dbMessage.reactions.size());
@@ -298,7 +298,7 @@ public class MessageTransformationTest extends BaseTransformationTest {
                 MessageTransformation.of(
                         m4, Instant.ofEpochMilli(1000), REMOTE, ogStanzaId, null, "id-user-a"));
 
-        final var messages = database.messageDao().getMessages(1L);
+        final var messages = database.messageDao().getMessagesForTesting(1L);
         Assert.assertEquals(1, messages.size());
         final var dbMessage = Iterables.getOnlyElement(messages);
         Assert.assertEquals(1, dbMessage.reactions.size());
@@ -363,7 +363,7 @@ public class MessageTransformationTest extends BaseTransformationTest {
                 MessageTransformation.of(
                         m4, Instant.ofEpochMilli(1000), REMOTE, ogStanzaId, null, "id-user-a"));
 
-        final var messages = database.messageDao().getMessages(1L);
+        final var messages = database.messageDao().getMessagesForTesting(1L);
         Assert.assertEquals(1, messages.size());
         final var dbMessage = Iterables.getOnlyElement(messages);
         Assert.assertEquals(2, dbMessage.reactions.size());
@@ -415,7 +415,7 @@ public class MessageTransformationTest extends BaseTransformationTest {
                         null,
                         "id-user-c"));
 
-        final var messages = database.messageDao().getMessages(1L);
+        final var messages = database.messageDao().getMessagesForTesting(1L);
         Assert.assertEquals(1, messages.size());
         final var dbMessage = Iterables.getOnlyElement(messages);
         Assert.assertEquals(2, dbMessage.reactions.size());
@@ -451,7 +451,7 @@ public class MessageTransformationTest extends BaseTransformationTest {
                 MessageTransformation.of(
                         m2, Instant.now(), REMOTE, "stanza-b", m2.getFrom().asBareJid(), null));
 
-        final var messages = database.messageDao().getMessages(1L);
+        final var messages = database.messageDao().getMessagesForTesting(1L);
         Assert.assertEquals(2, messages.size());
         final var response = Iterables.get(messages, 1);
         Assert.assertNotNull(response.inReplyToMessageEntityId);
@@ -486,7 +486,7 @@ public class MessageTransformationTest extends BaseTransformationTest {
                 MessageTransformation.of(
                         m2, Instant.now(), REMOTE, null, m2.getFrom().asBareJid(), null));
 
-        final var messages = database.messageDao().getMessages(1L);
+        final var messages = database.messageDao().getMessagesForTesting(1L);
         final var message = Iterables.getOnlyElement(messages);
 
         Assert.assertEquals(1L, message.states.size());
@@ -513,7 +513,7 @@ public class MessageTransformationTest extends BaseTransformationTest {
                 MessageTransformation.of(
                         m2, Instant.now(), REMOTE, null, m2.getFrom().asBareJid(), null));
 
-        final var messages = database.messageDao().getMessages(1L);
+        final var messages = database.messageDao().getMessagesForTesting(1L);
         final var message = Iterables.getOnlyElement(messages);
         Assert.assertEquals(Modification.RETRACTION, message.modification);
         Assert.assertEquals(PartType.RETRACTION, Iterables.getOnlyElement(message.contents).type);

app/src/main/java/im/conversations/android/database/dao/MessageDao.java

@@ -1,6 +1,8 @@
 package im.conversations.android.database.dao;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.VisibleForTesting;
+import androidx.paging.PagingSource;
 import androidx.room.Dao;
 import androidx.room.Insert;
 import androidx.room.Query;
@@ -420,6 +422,7 @@ public abstract class MessageDao {
                     + " reactionBy=:fromBare")
     protected abstract void deleteReactionsByFromBare(long messageEntityId, BareJid fromBare);
 
+    @VisibleForTesting
     @Transaction
     @Query(
             "SELECT message.id as"
@@ -431,7 +434,20 @@ public abstract class MessageDao {
                 + " message.senderIdentity=axolotl_identity.address AND"
                 + " message_version.identityKey=axolotl_identity.identityKey WHERE chat.id=:chatId"
                 + " AND latestVersion IS NOT NULL ORDER BY message.receivedAt")
-    public abstract List<MessageWithContentReactions> getMessages(long chatId);
+    public abstract List<MessageWithContentReactions> getMessagesForTesting(long chatId);
+
+    @Transaction
+    @Query(
+            "SELECT message.id as"
+                    + " id,sentAt,outgoing,toBare,toResource,fromBare,fromResource,modification,latestVersion"
+                    + " as version,inReplyToMessageEntityId,encryption,message_version.identityKey,trust"
+                    + " FROM chat JOIN message on message.chatId=chat.id JOIN message_version ON"
+                    + " message.latestVersion=message_version.id LEFT JOIN axolotl_identity ON"
+                    + " chat.accountId=axolotl_identity.accountId AND"
+                    + " message.senderIdentity=axolotl_identity.address AND"
+                    + " message_version.identityKey=axolotl_identity.identityKey WHERE chat.id=:chatId"
+                    + " AND latestVersion IS NOT NULL ORDER BY message.receivedAt DESC")
+    public abstract PagingSource<Integer,MessageWithContentReactions> getMessages(long chatId);
 
     public void setInReplyTo(
             ChatIdentifier chat,

app/src/main/java/im/conversations/android/database/model/MessageWithContentReactions.java

@@ -1,7 +1,10 @@
 package im.conversations.android.database.model;
 
 import androidx.room.Relation;
+
+import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableSortedSet;
+import com.google.common.collect.Iterables;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Multimaps;
 import im.conversations.android.database.entity.MessageContentEntity;
@@ -68,4 +71,11 @@ public class MessageWithContentReactions {
                 (a, b) -> Integer.compare(b.getValue(), a.getValue()),
                 aggregatedReactions.entrySet());
     }
+
+    public String textContent() {
+        final var content = Iterables.getFirst(this.contents,null);
+        final var text = Strings.nullToEmpty(content == null ? null : content.body);
+        return text;
+        //return text.substring(0,Math.min(text.length(),20));
+    }
 }

app/src/main/java/im/conversations/android/repository/ChatRepository.java

@@ -7,6 +7,8 @@ import im.conversations.android.database.model.ChatFilter;
 import im.conversations.android.database.model.ChatInfo;
 import im.conversations.android.database.model.ChatOverviewItem;
 import im.conversations.android.database.model.GroupIdentifier;
+import im.conversations.android.database.model.MessageWithContentReactions;
+
 import java.util.List;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -30,4 +32,8 @@ public class ChatRepository extends AbstractRepository {
     public LiveData<ChatInfo> getChatInfo(final long chatId) {
         return this.database.chatDao().getChatInfo(chatId);
     }
+
+    public PagingSource<Integer, MessageWithContentReactions> getMessages(final long chatId) {
+        return this.database.messageDao().getMessages(chatId);
+    }
 }

app/src/main/java/im/conversations/android/ui/RecyclerViewScroller.java

@@ -0,0 +1,107 @@
+package im.conversations.android.ui;
+
+import androidx.paging.PagingDataAdapter;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.lang.ref.WeakReference;
+import java.util.Objects;
+
+public class RecyclerViewScroller {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(RecyclerViewScroller.class);
+
+    private final RecyclerView recyclerView;
+
+
+    public RecyclerViewScroller(RecyclerView recyclerView) {
+        this.recyclerView = recyclerView;
+    }
+
+    public void scrollToPosition(final int position) {
+        final ReliableScroller reliableScroller = new ReliableScroller(recyclerView);
+        reliableScroller.scrollToPosition(position);
+    }
+
+    private static class ReliableScroller {
+
+        private static final int MAX_DELAY = 2000;
+        private static final int INTERVAL = 50;
+
+        private final WeakReference<RecyclerView> recyclerViewReference;
+
+        private int accumulatedDelay = 0;
+
+
+        private ReliableScroller(RecyclerView recyclerView) {
+            this.recyclerViewReference = new WeakReference<>(recyclerView);
+        }
+
+        private void scrollToPosition(final int position) {
+            final var recyclerView = this.recyclerViewReference.get();
+            if (recyclerView == null) {
+                return;
+            }
+            final var isItemLoaded = isItemLoaded(recyclerView, position);
+            final var isSurroundingRendered = isSurroundingRendered(recyclerView, position);
+            final var doneUpdating = !recyclerView.hasPendingAdapterUpdates();
+            final var viewHolder = recyclerView.findViewHolderForAdapterPosition(position);
+            LOGGER.info("Item is loaded {}, isSurroundingRendered {}, doneUpdating {} accumulatedDelay {}", isItemLoaded, isSurroundingRendered, doneUpdating, accumulatedDelay);
+            if ((isItemLoaded && isSurroundingRendered && doneUpdating && viewHolder != null) || accumulatedDelay >= MAX_DELAY) {
+                final var layoutManager = recyclerView.getLayoutManager();
+                if (viewHolder != null && layoutManager instanceof LinearLayoutManager llm) {
+                    final var child = viewHolder.itemView;
+                    final int offset = recyclerView.getHeight() / 2 - child.getHeight() / 2;
+                    LOGGER.info("scrollToPositionWithOffset({},{})", position, offset);
+                    llm.scrollToPositionWithOffset(position, offset);
+                } else {
+                     LOGGER.info("scrollToPosition({})", position);
+                    recyclerView.scrollToPosition(position);
+                }
+                return;
+            }
+            recyclerView.scrollToPosition(position);
+            accumulatedDelay += INTERVAL;
+            recyclerView.postDelayed(()->{
+                scrollToPosition(position);
+            },INTERVAL);
+        }
+
+        private static boolean isSurroundingRendered(final RecyclerView recyclerView, final int requestedPosition) {
+            final var layoutManager = recyclerView.getLayoutManager();
+            if (layoutManager instanceof LinearLayoutManager llm) {
+                final var first = llm.findFirstVisibleItemPosition();
+                final var last = llm.findLastVisibleItemPosition();
+                if (first == -1 || last == -1) {
+                    return false;
+                }
+                final var isItemLoaded = isItemLoaded(recyclerView, first) && isItemLoaded(recyclerView, last);
+                if (isItemLoaded) {
+                    final var requestedIsOnly = first == requestedPosition && last == requestedPosition;
+                    final var firstCompletelyVisible = llm.findFirstCompletelyVisibleItemPosition();
+                    final var lastCompletelyVisible = llm.findLastCompletelyVisibleItemPosition();
+
+                    final var requestedInRange = firstCompletelyVisible <= requestedPosition && requestedPosition <= lastCompletelyVisible;
+                    LOGGER.info("firstComp {} lastComp {} requested {} inRange {}", firstCompletelyVisible, lastCompletelyVisible, requestedPosition, requestedInRange);
+                    return requestedIsOnly || requestedInRange;
+                } else {
+                    return false;
+                }
+            } else {
+                return false;
+            }
+        }
+
+        private static boolean isItemLoaded(final RecyclerView recyclerView, final int position) {
+            final var adapter = recyclerView.getAdapter();
+            if (adapter instanceof PagingDataAdapter<?,?> pagingDataAdapter) {
+                return Objects.nonNull(pagingDataAdapter.peek(position));
+            } else {
+                return true;
+            }
+        }
+    }
+}

app/src/main/java/im/conversations/android/ui/adapter/ChatOverviewAdapter.java

@@ -10,7 +10,7 @@ import androidx.recyclerview.widget.DiffUtil;
 import androidx.recyclerview.widget.RecyclerView;
 import im.conversations.android.R;
 import im.conversations.android.database.model.ChatOverviewItem;
-import im.conversations.android.databinding.ItemChatoverviewBinding;
+import im.conversations.android.databinding.ItemChatOverviewBinding;
 import im.conversations.android.ui.AvatarFetcher;
 import java.util.function.Consumer;
 import org.slf4j.Logger;
@@ -33,7 +33,7 @@ public class ChatOverviewAdapter
         return new ChatOverviewViewHolder(
                 DataBindingUtil.inflate(
                         LayoutInflater.from(parent.getContext()),
-                        R.layout.item_chatoverview,
+                        R.layout.item_chat_overview,
                         parent,
                         false));
     }
@@ -68,9 +68,9 @@ public class ChatOverviewAdapter
 
     public static class ChatOverviewViewHolder extends RecyclerView.ViewHolder {
 
-        private final ItemChatoverviewBinding binding;
+        private final ItemChatOverviewBinding binding;
 
-        public ChatOverviewViewHolder(@NonNull ItemChatoverviewBinding binding) {
+        public ChatOverviewViewHolder(@NonNull ItemChatOverviewBinding binding) {
             super(binding.getRoot());
             this.binding = binding;
         }

app/src/main/java/im/conversations/android/ui/adapter/MessageAdapter.java

@@ -0,0 +1,75 @@
+package im.conversations.android.ui.adapter;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.annotation.NonNull;
+import androidx.databinding.DataBindingUtil;
+import androidx.paging.PagingDataAdapter;
+import androidx.recyclerview.widget.DiffUtil;
+import androidx.recyclerview.widget.RecyclerView;
+
+import im.conversations.android.R;
+import im.conversations.android.database.model.MessageWithContentReactions;
+import im.conversations.android.databinding.ItemMessageReceivedBinding;
+
+public class MessageAdapter extends PagingDataAdapter<MessageWithContentReactions, MessageAdapter.AbstractMessageViewHolder> {
+
+    public MessageAdapter(@NonNull DiffUtil.ItemCallback<MessageWithContentReactions> diffCallback) {
+        super(diffCallback);
+    }
+
+    @NonNull
+    @Override
+    public AbstractMessageViewHolder onCreateViewHolder(final @NonNull ViewGroup parent, final int viewType) {
+        final var layoutInflater = LayoutInflater.from(parent.getContext());
+        if (viewType == 0) {
+            return new MessageReceivedViewHolder(DataBindingUtil.inflate(
+                    layoutInflater,
+                    R.layout.item_message_received,
+                    parent,
+                    false));
+        }
+        throw new IllegalArgumentException(String.format("viewType %d not implemented", viewType));
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull AbstractMessageViewHolder holder, int position) {
+        final var message = getItem(position);
+        if (message == null) {
+            holder.setMessage(null);
+        }
+        holder.setMessage(message);
+    }
+
+    protected abstract static class AbstractMessageViewHolder extends RecyclerView.ViewHolder {
+
+        private AbstractMessageViewHolder(@NonNull View itemView) {
+            super(itemView);
+        }
+
+        protected abstract void setMessage(final MessageWithContentReactions message);
+    }
+
+    public static class MessageReceivedViewHolder extends AbstractMessageViewHolder {
+
+        private final ItemMessageReceivedBinding binding;
+
+
+        public MessageReceivedViewHolder(@NonNull ItemMessageReceivedBinding binding) {
+            super(binding.getRoot());
+            this.binding = binding;
+        }
+
+        @Override
+        protected void setMessage(final MessageWithContentReactions message) {
+            if (message == null) {
+                this.binding.setMessage(null);
+                this.binding.text.setText("(placeholder)");
+            } else {
+                this.binding.setMessage(message);
+            }
+        }
+    }
+}

app/src/main/java/im/conversations/android/ui/adapter/MessageComparator.java

@@ -0,0 +1,18 @@
+package im.conversations.android.ui.adapter;
+
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.DiffUtil;
+
+import im.conversations.android.database.model.MessageWithContentReactions;
+
+public class MessageComparator extends DiffUtil.ItemCallback<MessageWithContentReactions> {
+    @Override
+    public boolean areItemsTheSame(@NonNull MessageWithContentReactions oldItem, @NonNull MessageWithContentReactions newItem) {
+        return oldItem.id == newItem.id;
+    }
+
+    @Override
+    public boolean areContentsTheSame(@NonNull MessageWithContentReactions oldItem, @NonNull MessageWithContentReactions newItem) {
+        return false;
+    }
+}

app/src/main/java/im/conversations/android/ui/fragment/main/ChatFragment.java

@@ -1,50 +1,96 @@
 package im.conversations.android.ui.fragment.main;
 
 import android.os.Bundle;
+import android.os.Handler;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import androidx.annotation.NonNull;
 import androidx.databinding.DataBindingUtil;
 import androidx.fragment.app.Fragment;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.Observer;
+import androidx.lifecycle.Transformations;
 import androidx.lifecycle.ViewModelProvider;
+import androidx.paging.CombinedLoadStates;
+import androidx.paging.LoadState;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+
 import im.conversations.android.R;
 import im.conversations.android.databinding.FragmentChatBinding;
 import im.conversations.android.ui.Activities;
 import im.conversations.android.ui.NavControllers;
+import im.conversations.android.ui.RecyclerViewScroller;
+import im.conversations.android.ui.adapter.MessageAdapter;
+import im.conversations.android.ui.adapter.MessageComparator;
 import im.conversations.android.ui.model.ChatViewModel;
+import kotlin.Unit;
+import kotlin.jvm.functions.Function1;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.Objects;
+
 public class ChatFragment extends Fragment {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(ChatFragment.class);
 
     private FragmentChatBinding binding;
     private ChatViewModel chatViewModel;
+    private MessageAdapter messageAdapter;
+    private RecyclerViewScroller recyclerViewScroller;
 
     @Override
     public View onCreateView(
             @NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         super.onCreateView(inflater, container, savedInstanceState);
         this.binding = DataBindingUtil.inflate(inflater, R.layout.fragment_chat, container, false);
-        final long chatId = ChatFragmentArgs.fromBundle(getArguments()).getChat();
+        final long chatId = ChatFragmentArgs.fromBundle(requireArguments()).getChat();
         final ViewModelProvider viewModelProvider =
                 new ViewModelProvider(this, getDefaultViewModelProviderFactory());
         this.chatViewModel = viewModelProvider.get(ChatViewModel.class);
         this.chatViewModel.setChatId(chatId);
         this.binding.setChatViewModel(this.chatViewModel);
         this.binding.setLifecycleOwner(getViewLifecycleOwner());
+        final var linearLayoutManager = new LinearLayoutManager(requireContext());
+        //linearLayoutManager.setStackFromEnd(true);
+        linearLayoutManager.setReverseLayout(true);
+        this.binding.messages.setLayoutManager(linearLayoutManager);
+        this.recyclerViewScroller = new RecyclerViewScroller(this.binding.messages);
+        this.messageAdapter = new MessageAdapter(new MessageComparator());
+        this.binding.messages.setAdapter(this.messageAdapter);
+
+        this.chatViewModel
+                .getMessages()
+                .observe(
+                        getViewLifecycleOwner(),
+                        pagingData -> {
+                            LOGGER.info("submitData()");
+                            messageAdapter.submitData(getLifecycle(), pagingData);
+                        });
         this.binding.materialToolbar.setNavigationOnClickListener(
                 view -> {
                     NavControllers.findNavController(requireActivity(), R.id.nav_host_fragment)
                             .popBackStack();
                 });
+        this.binding.addContent.setOnClickListener(v ->{
+            scrollToPosition(messageAdapter.getItemCount() - 1);
+
+        });
         this.binding.messageLayout.setEndIconOnClickListener(
                 v -> {
-                    LOGGER.info("On send pressed");
+                    scrollToPosition(0);
                 });
         Activities.setStatusAndNavigationBarColors(requireActivity(), binding.getRoot(), true);
         return this.binding.getRoot();
     }
+
+    private void scrollToPosition(final int position) {
+        LOGGER.info("scrollToPosition({})",position);
+        this.recyclerViewScroller.scrollToPosition(position);
+    }
+
 }

app/src/main/java/im/conversations/android/ui/model/ChatViewModel.java

@@ -6,8 +6,18 @@ import androidx.lifecycle.AndroidViewModel;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.Transformations;
+import androidx.lifecycle.ViewModelKt;
+import androidx.paging.Pager;
+import androidx.paging.PagingConfig;
+import androidx.paging.PagingData;
+import androidx.paging.PagingLiveData;
+
 import im.conversations.android.database.model.ChatInfo;
+import im.conversations.android.database.model.ChatOverviewItem;
+import im.conversations.android.database.model.MessageWithContentReactions;
 import im.conversations.android.repository.ChatRepository;
+import kotlinx.coroutines.CoroutineScope;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -18,6 +28,7 @@ public class ChatViewModel extends AndroidViewModel {
     private final ChatRepository chatRepository;
     private final MutableLiveData<Long> chatId = new MutableLiveData<>();
     private final LiveData<ChatInfo> chatInfo;
+    private final LiveData<PagingData<MessageWithContentReactions>> messages;
 
     public ChatViewModel(@NonNull Application application) {
         super(application);
@@ -26,6 +37,16 @@ public class ChatViewModel extends AndroidViewModel {
                 Transformations.switchMap(
                         this.chatId,
                         chatId -> chatId == null ? null : chatRepository.getChatInfo(chatId));
+        final var messages = Transformations.switchMap(this.chatId, chatId -> {
+            final Pager<Integer, MessageWithContentReactions> pager =
+                    new Pager<>(
+                            new PagingConfig(30),
+                            () -> chatRepository.getMessages(chatId));
+            return PagingLiveData.getLiveData(pager);
+        });
+        final var  viewModelScope = ViewModelKt.getViewModelScope(this);
+        this.messages =  PagingLiveData.cachedIn(messages, viewModelScope);
+
     }
 
     public void setChatId(final long chatId) {
@@ -36,4 +57,8 @@ public class ChatViewModel extends AndroidViewModel {
         return Transformations.map(
                 this.chatInfo, chatInfo -> chatInfo == null ? null : chatInfo.name());
     }
+
+    public LiveData<PagingData<MessageWithContentReactions>> getMessages() {
+        return this.messages;
+    }
 }

app/src/main/res/drawable/background_message_received.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <solid android:color="?colorSecondaryContainer"/>
+    <corners android:radius="16dp"/>
+</shape>

app/src/main/res/layout/fragment_chat.xml

@@ -37,7 +37,7 @@
                 app:menu="@menu/fragment_chat"/>
         </com.google.android.material.appbar.AppBarLayout>
 
-        <androidx.constraintlayout.widget.ConstraintLayout
+        <RelativeLayout
             android:id="@+id/chat"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
@@ -45,64 +45,73 @@
             app:layout_behavior="@string/appbar_scrolling_view_behavior">
 
             <androidx.recyclerview.widget.RecyclerView
-                android:id="@+id/chats"
+                android:id="@+id/messages"
                 android:layout_width="match_parent"
-                android:layout_height="0dp"
+                android:layout_height="match_parent"
-                app:layout_constraintBottom_toTopOf="@+id/message_layout"
+                android:layout_above="@+id/compose_box"
-                app:layout_constraintTop_toTopOf="parent" />
+                app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
+                tools:listitem="@layout/item_message_received"/>
 
-            <Button
+            <androidx.constraintlayout.widget.ConstraintLayout
-                android:layout_marginStart="8dp"
+                android:id="@+id/compose_box"
-                android:id="@+id/add_content"
+                android:layout_alignParentBottom="true"
-                style="?attr/materialIconButtonStyle"
+                android:layout_width="match_parent"
-                android:layout_width="wrap_content"
+                android:layout_height="wrap_content">
-                android:layout_height="wrap_content"
-                app:icon="@drawable/ic_add_circle_outline_24dp"
-                app:iconTint="?colorOnSurface"
-                app:iconSize="24dp"
-                android:padding="8dp"
-                app:layout_constraintBottom_toBottomOf="@+id/message_layout"
-                app:layout_constraintEnd_toStartOf="@+id/message_layout"
-                app:layout_constraintStart_toStartOf="parent" />
 
-            <com.google.android.material.textfield.TextInputLayout
+                <Button
-                android:id="@+id/message_layout"
+                    android:id="@+id/add_content"
-                style="@style/Widget.Material3.TextInputLayout.FilledBox"
+                    style="?attr/materialIconButtonStyle"
-                android:theme="@style/ThemeOverlay.C3.TextSelection.Secondary"
+                    android:layout_width="wrap_content"
-                android:layout_width="0dp"
-                android:layout_height="wrap_content"
-                android:layout_margin="8dp"
-                android:minHeight="48dp"
-                app:boxBackgroundColor="?colorTertiaryContainer"
-                app:boxCornerRadiusBottomEnd="24dp"
-                app:boxCornerRadiusBottomStart="24dp"
-                app:boxCornerRadiusTopEnd="24dp"
-                app:boxCornerRadiusTopStart="24dp"
-                app:boxStrokeWidth="0dp"
-                app:boxStrokeWidthFocused="0dp"
-                app:endIconDrawable="@drawable/ic_send_24dp"
-                app:endIconMode="custom"
-                app:endIconTint="?colorOnTertiaryContainer"
-                app:expandedHintEnabled="false"
-                app:helperTextEnabled="false"
-                app:hintEnabled="false"
-                app:layout_constraintBottom_toBottomOf="parent"
-                app:layout_constraintEnd_toEndOf="parent"
-                app:layout_constraintStart_toEndOf="@+id/add_content">
-
-                <com.google.android.material.textfield.TextInputEditText
-                    style="@style/Widget.C3.TextInputEditText.FilledBox.Tertiary"
-                    android:theme="@style/ThemeOverlay.C3.TextSelection.Secondary"
-                    android:id="@+id/message"
-                    android:layout_width="match_parent"
                     android:layout_height="wrap_content"
-                    android:hint="@string/send_message"
                     android:padding="8dp"
-                    android:maxHeight="112dp" />
+                    app:icon="@drawable/ic_add_circle_outline_24dp"
+                    app:iconSize="24dp"
+                    app:iconTint="?colorOnSurface"
+                    app:layout_constraintBottom_toBottomOf="@+id/message_layout"
+                    app:layout_constraintStart_toStartOf="parent" />
 
-            </com.google.android.material.textfield.TextInputLayout>
+                <com.google.android.material.textfield.TextInputLayout
+                    android:id="@+id/message_layout"
+                    style="@style/Widget.Material3.TextInputLayout.FilledBox"
+                    android:theme="@style/ThemeOverlay.C3.TextSelection.Secondary"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_margin="8dp"
+                    android:minHeight="48dp"
+                    app:boxBackgroundColor="?colorTertiaryContainer"
+                    app:boxCornerRadiusBottomEnd="24dp"
+                    app:boxCornerRadiusBottomStart="24dp"
+                    app:boxCornerRadiusTopEnd="24dp"
+                    app:boxCornerRadiusTopStart="24dp"
+                    app:boxStrokeWidth="0dp"
+                    app:boxStrokeWidthFocused="0dp"
+                    app:endIconDrawable="@drawable/ic_send_24dp"
+                    app:endIconMode="custom"
+                    app:endIconTint="?colorOnTertiaryContainer"
+                    app:expandedHintEnabled="false"
+                    app:helperTextEnabled="false"
+                    app:hintEnabled="false"
+                    app:layout_constraintTop_toTopOf="parent"
+                    app:layout_constraintBottom_toBottomOf="parent"
+                    app:layout_constraintEnd_toEndOf="parent"
+                    app:layout_constraintStart_toEndOf="@+id/add_content">
 
-        </androidx.constraintlayout.widget.ConstraintLayout>
+                    <com.google.android.material.textfield.TextInputEditText
+                        style="@style/Widget.C3.TextInputEditText.FilledBox.Tertiary"
+                        android:theme="@style/ThemeOverlay.C3.TextSelection.Secondary"
+                        android:id="@+id/message"
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:hint="@string/send_message"
+                        android:padding="8dp"
+                        android:maxHeight="112dp" />
+
+                </com.google.android.material.textfield.TextInputLayout>
+
+            </androidx.constraintlayout.widget.ConstraintLayout>
+
+
+        </RelativeLayout>
     </androidx.coordinatorlayout.widget.CoordinatorLayout>
 
     <data>

app/src/main/res/layout/fragment_overview.xml

@@ -18,7 +18,7 @@
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"
                 app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
-                tools:listitem="@layout/item_chatoverview"
+                tools:listitem="@layout/item_chat_overview"
                 android:fillViewport="true"
                 app:layout_behavior="@string/appbar_scrolling_view_behavior" />
 

app/src/main/res/layout/item_message_received.xml

@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="utf-8"?>
+<layout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools">
+
+    <androidx.constraintlayout.widget.ConstraintLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <ImageView
+            android:id="@+id/avatar"
+            android:layout_width="@dimen/avatar_chat_overview_size"
+            android:layout_height="@dimen/avatar_chat_overview_size"
+            android:layout_marginStart="8dp"
+            android:scaleType="centerCrop"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintStart_toStartOf="parent" />
+
+        <androidx.constraintlayout.widget.ConstraintLayout
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginHorizontal="8dp"
+            android:background="@drawable/background_message_received"
+            android:minHeight="40dp"
+            android:padding="8dp"
+            android:layout_marginTop="4dp"
+            app:layout_constrainedWidth="true"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintHorizontal_bias="0.0"
+            app:layout_constraintStart_toEndOf="@id/avatar"
+            app:layout_constraintTop_toTopOf="parent">
+
+            <TextView
+                android:id="@+id/text"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:textColor="?colorOnSecondaryContainer"
+                app:layout_constraintBottom_toBottomOf="parent"
+                app:layout_constraintStart_toStartOf="parent"
+                app:layout_constraintTop_toTopOf="parent"
+                android:text="@{message.textContent}"
+                tools:text="Fusce vitae vehicula risus, nec ornare lorem. Quisque facilisis mattis velit ac porttitor. Aenean aliquet pretium varius. Quisque neque felis, mattis sit amet leo ac, tempus dapibus nibh." />
+
+        </androidx.constraintlayout.widget.ConstraintLayout>
+
+
+    </androidx.constraintlayout.widget.ConstraintLayout>
+
+    <data>
+        <import type="android.view.View" />
+        <variable
+            name="message"
+            type="im.conversations.android.database.model.MessageWithContentReactions" />
+    </data>
+</layout>