unread message indicator

app/src/main/java/chat/rocket/android/fragment/chatroom/RoomFragment.java

@@ -6,6 +6,7 @@ import android.content.Intent;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
+import android.support.design.widget.Snackbar;
 import android.support.v4.view.GravityCompat;
 import android.support.v4.widget.DrawerLayout;
 import android.support.v4.widget.SlidingPaneLayout;
@@ -32,6 +33,7 @@ import chat.rocket.android.helper.RecyclerViewScrolledToBottomListener;
 import chat.rocket.android.helper.TextUtils;
 import chat.rocket.android.layouthelper.chatroom.MessageFormManager;
 import chat.rocket.android.layouthelper.chatroom.MessageListAdapter;
+import chat.rocket.android.layouthelper.chatroom.NewMessageIndicatorManager;
 import chat.rocket.android.layouthelper.chatroom.PairedMessage;
 import chat.rocket.android.layouthelper.extra_action.MessageExtraActionBehavior;
 import chat.rocket.android.layouthelper.extra_action.upload.AbstractUploadActionItem;
@@ -73,6 +75,9 @@ public class RoomFragment extends AbstractChatRoomFragment
   private RealmObjectObserver<LoadMessageProcedure> procedureObserver;
   private MessageFormManager messageFormManager;
   private RecyclerViewAutoScrollManager autoScrollManager;
+  private NewMessageIndicatorManager newMessageIndicatorManager;
+  private Snackbar unreadIndicator;
+  private boolean previousUnreadMessageExists;
 
   public RoomFragment() {
   }
@@ -148,7 +153,14 @@ public class RoomFragment extends AbstractChatRoomFragment
     LinearLayoutManager layoutManager = new LinearLayoutManager(getContext(),
         LinearLayoutManager.VERTICAL, true);
     listView.setLayoutManager(layoutManager);
-    autoScrollManager = new RecyclerViewAutoScrollManager(layoutManager);
+    autoScrollManager = new RecyclerViewAutoScrollManager(layoutManager) {
+      @Override
+      protected void onAutoScrollMissed() {
+        if (newMessageIndicatorManager != null) {
+          newMessageIndicatorManager.updateNewMessageCount(getUnreadMessageCount());
+        }
+      }
+    };
     adapter.registerAdapterDataObserver(autoScrollManager);
 
     scrollListener = new LoadMoreScrollListener(layoutManager, 40) {
@@ -161,10 +173,59 @@ public class RoomFragment extends AbstractChatRoomFragment
     listView.addOnScrollListener(
         new RecyclerViewScrolledToBottomListener(layoutManager, 1, this::markAsReadIfNeeded));
 
+    newMessageIndicatorManager = new NewMessageIndicatorManager() {
+      @Override
+      protected void onShowIndicator(int count, boolean onlyAlreadyShown) {
+        if ((onlyAlreadyShown && unreadIndicator != null && unreadIndicator.isShown())
+            || !onlyAlreadyShown) {
+          unreadIndicator = getUnreadCountIndicatorView(count);
+          unreadIndicator.show();
+        }
+      }
+
+      @Override
+      protected void onHideIndicator() {
+        if (unreadIndicator != null && unreadIndicator.isShown()) {
+          unreadIndicator.dismiss();
+        }
+      }
+    };
+
     setupSideMenu();
     setupMessageComposer();
   }
 
+  private void scrollToLatestMessage() {
+    RecyclerView listView = (RecyclerView) rootView.findViewById(R.id.recyclerview);
+    if (listView != null) {
+      listView.smoothScrollToPosition(0);
+    }
+  }
+
+  private Snackbar getUnreadCountIndicatorView(int count) {
+    // TODO: replace with another custom View widget, not to hide message composer.
+    final String caption = getResources().getString(
+        R.string.fmt_dialog_view_latest_message_title, count);
+
+    return Snackbar.make(rootView, caption, Snackbar.LENGTH_LONG)
+        .setAction(R.string.dialog_view_latest_message_action, view -> scrollToLatestMessage());
+  }
+
+  private int getUnreadMessageCount() {
+    RoomSubscription room = realmHelper.executeTransactionForRead(realm ->
+        realm.where(RoomSubscription.class).equalTo(RoomSubscription.ROOM_ID, roomId).findFirst());
+    if (room != null) {
+      return realmHelper.executeTransactionForReadResults(realm ->
+          realm.where(Message.class)
+              .equalTo(Message.ROOM_ID, roomId)
+              .greaterThanOrEqualTo(Message.TIMESTAMP, room.getLastSeen())
+              .notEqualTo(Message.USER_ID, userId)
+              .findAll()).size();
+    } else {
+      return 0;
+    }
+  }
+
   @Override
   public void onDestroyView() {
     RecyclerView listView = (RecyclerView) rootView.findViewById(R.id.recyclerview);
@@ -244,7 +305,11 @@ public class RoomFragment extends AbstractChatRoomFragment
                 .put(Message.SYNC_STATE, SyncState.NOT_SYNCED)
                 .put(Message.TIMESTAMP, System.currentTimeMillis())
                 .put(Message.ROOM_ID, roomId)
-                .put(Message.MESSAGE, messageText))));
+                .put(Message.MESSAGE, messageText)))
+            .onSuccess(_task -> {
+              scrollToLatestMessage();
+              return null;
+            }));
     messageFormManager.registerExtraActionItem(new ImageUploadActionItem());
     messageFormManager.registerExtraActionItem(new AudioUploadActionItem());
     messageFormManager.registerExtraActionItem(new VideoUploadActionItem());
@@ -289,6 +354,12 @@ public class RoomFragment extends AbstractChatRoomFragment
       setToolbarRoomIcon(0);
     }
     setToolbarTitle(roomSubscription.getName());
+
+    boolean unreadMessageExists = roomSubscription.isAlert();
+    if (newMessageIndicatorManager != null && previousUnreadMessageExists && !unreadMessageExists) {
+      newMessageIndicatorManager.reset();
+    }
+    previousUnreadMessageExists = unreadMessageExists;
   }
 
   private void onUpdateLoadMessageProcedure(LoadMessageProcedure procedure) {
@@ -360,7 +431,6 @@ public class RoomFragment extends AbstractChatRoomFragment
     roomObserver.sub();
     procedureObserver.sub();
     closeSideMenuIfNeeded();
-    markAsReadIfNeeded();
   }
 
   @Override

app/src/main/java/chat/rocket/android/helper/RecyclerViewAutoScrollManager.java

@@ -20,6 +20,12 @@ public class RecyclerViewAutoScrollManager extends RecyclerView.AdapterDataObser
 
     if (linearLayoutManager.findFirstVisibleItemPosition() <= positionStart) {
       linearLayoutManager.scrollToPosition(positionStart);
+    } else {
+      onAutoScrollMissed();
     }
   }
+
+  protected void onAutoScrollMissed() {
+    //do nothing by default.
+  }
 }

app/src/main/java/chat/rocket/android/layouthelper/chatroom/NewMessageIndicatorManager.java

+package chat.rocket.android.layouthelper.chatroom;
+
+/**
+ * manager class for showing "You have XX messages" indicator.
+ */
+public abstract class NewMessageIndicatorManager {
+  private int count;
+  private boolean onlyAlreadyShown;
+
+  /**
+   * update the number of unread message.
+   */
+  public void updateNewMessageCount(int count) {
+    if (count > 0) {
+      this.count = count;
+      update();
+      onlyAlreadyShown = true;
+    } else {
+      reset();
+    }
+  }
+
+  /**
+   * Should call this method when user checked new message.
+   */
+  public void reset() {
+    count = 0;
+    onlyAlreadyShown = false;
+    update();
+  }
+
+  private void update() {
+    if (count > 0) {
+      onShowIndicator(count, onlyAlreadyShown);
+    } else {
+      onHideIndicator();
+    }
+  }
+
+  protected abstract void onShowIndicator(int count, boolean onlyAlreadyShown);
+
+  protected abstract void onHideIndicator();
+}

app/src/main/java/chat/rocket/android/model/ddp/Message.java

@@ -25,6 +25,7 @@ public class Message extends RealmObject {
   @SuppressWarnings({"PMD.AvoidFieldNameMatchingTypeName"})
   public static final String MESSAGE = "msg";
   public static final String USER = "u";
+  public static final String USER_ID = "u._id";
   public static final String GROUPABLE = "groupable";
   public static final String ATTACHMENTS = "attachments";
   public static final String URLS = "urls";

app/src/main/res/values/strings.xml

@@ -18,6 +18,9 @@
     <string name="resend">Resend</string>
     <string name="discard">Discard</string>
 
+    <string name="fmt_dialog_view_latest_message_title">New %d messages</string>
+    <string name="dialog_view_latest_message_action">View</string>
+
     <string name="file_uploading_title">Uploading…</string>
 
     <string name="dialog_user_registration_email">Email</string>