add NotificationItem model.

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

@@ -23,6 +23,8 @@ public class RoomSubscription extends RealmObject {
   private boolean open;
   private boolean alert;
   private int unread;
+  private long _updatedAt;
+  private long ls; //last seen.
 
   public String get_id() {
     return _id;
@@ -80,7 +82,35 @@ public class RoomSubscription extends RealmObject {
     this.unread = unread;
   }
 
+  public long get_updatedAt() {
+    return _updatedAt;
+  }
+
+  public void set_updatedAt(long _updatedAt) {
+    this._updatedAt = _updatedAt;
+  }
+
+  public long getLs() {
+    return ls;
+  }
+
+  public void setLs(long ls) {
+    this.ls = ls;
+  }
+
   public static JSONObject customizeJson(JSONObject roomSubscriptionJson) throws JSONException {
+    if (!roomSubscriptionJson.isNull("ls")) {
+      long ls = roomSubscriptionJson.getJSONObject("ls").getLong("$date");
+      roomSubscriptionJson.remove("ls");
+      roomSubscriptionJson.put("ls", ls);
+    }
+
+    if (!roomSubscriptionJson.isNull("_updatedAt")) {
+      long updatedAt = roomSubscriptionJson.getJSONObject("_updatedAt").getLong("$date");
+      roomSubscriptionJson.remove("_updatedAt");
+      roomSubscriptionJson.put("_updatedAt", updatedAt);
+    }
+
     return roomSubscriptionJson;
   }
 }

app/src/main/java/chat/rocket/android/model/internal/NotificationItem.java

+package chat.rocket.android.model.internal;
+
+import io.realm.RealmObject;
+import io.realm.annotations.PrimaryKey;
+
+/**
+ * View model for notification.
+ */
+public class NotificationItem extends RealmObject {
+  @PrimaryKey private String roomId;
+  private String title;
+  private String description;
+  private int unreadCount;
+  private String senderName;
+  private long contentUpdatedAt; //subscription._updatedAt
+  private long lastSeenAt; //max(notification dismissed, subscription.ls)
+
+  public String getRoomId() {
+    return roomId;
+  }
+
+  public void setRoomId(String roomId) {
+    this.roomId = roomId;
+  }
+
+  public String getTitle() {
+    return title;
+  }
+
+  public void setTitle(String title) {
+    this.title = title;
+  }
+
+  public String getDescription() {
+    return description;
+  }
+
+  public void setDescription(String description) {
+    this.description = description;
+  }
+
+  public int getUnreadCount() {
+    return unreadCount;
+  }
+
+  public void setUnreadCount(int unreadCount) {
+    this.unreadCount = unreadCount;
+  }
+
+  public String getSenderName() {
+    return senderName;
+  }
+
+  public void setSenderName(String senderName) {
+    this.senderName = senderName;
+  }
+
+  public long getContentUpdatedAt() {
+    return contentUpdatedAt;
+  }
+
+  public void setContentUpdatedAt(long contentUpdatedAt) {
+    this.contentUpdatedAt = contentUpdatedAt;
+  }
+
+  public long getLastSeenAt() {
+    return lastSeenAt;
+  }
+
+  public void setLastSeenAt(long lastSeenAt) {
+    this.lastSeenAt = lastSeenAt;
+  }
+}

app/src/main/java/chat/rocket/android/service/RocketChatWebSocketThread.java

@@ -22,7 +22,7 @@ import chat.rocket.android.service.observer.GetUsersOfRoomsProcedureObserver;
 import chat.rocket.android.service.observer.LoadMessageProcedureObserver;
 import chat.rocket.android.service.observer.MethodCallObserver;
 import chat.rocket.android.service.observer.NewMessageObserver;
-import chat.rocket.android.service.observer.ReactiveNotificationCancelManager;
+import chat.rocket.android.service.observer.NotificationItemObserver;
 import chat.rocket.android.service.observer.ReactiveNotificationManager;
 import chat.rocket.android.service.observer.SessionObserver;
 import chat.rocket.android.service.observer.TokenLoginObserver;
@@ -49,7 +49,7 @@ public class RocketChatWebSocketThread extends HandlerThread {
       NewMessageObserver.class,
       CurrentUserObserver.class,
       ReactiveNotificationManager.class,
-      ReactiveNotificationCancelManager.class
+      NotificationItemObserver.class
   };
   private final Context appContext;
   private final String serverConfigId;

app/src/main/java/chat/rocket/android/service/ddp/stream/StreamNotifyUserSubscriptionsChanged.java

@@ -5,6 +5,8 @@ import chat.rocket.android.api.DDPClientWraper;
 import chat.rocket.android.model.ddp.RoomSubscription;
 import chat.rocket.android.realm_helper.RealmHelper;
 import io.realm.RealmObject;
+import org.json.JSONException;
+import org.json.JSONObject;
 
 public class StreamNotifyUserSubscriptionsChanged extends AbstractStreamNotifyUserEventSubscriber {
   public StreamNotifyUserSubscriptionsChanged(Context context, String hostname,
@@ -20,6 +22,10 @@ public class StreamNotifyUserSubscriptionsChanged extends AbstractStreamNotifyUs
     return RoomSubscription.class;
   }
 
+  @Override protected JSONObject customizeFieldJson(JSONObject json) throws JSONException {
+    return RoomSubscription.customizeJson(super.customizeFieldJson(json));
+  }
+
   @Override protected String getPrimaryKeyForModel() {
     return "rid";
   }

app/src/main/java/chat/rocket/android/service/observer/CurrentUserObserver.java

@@ -3,6 +3,7 @@ package chat.rocket.android.service.observer;
 import android.content.Context;
 import chat.rocket.android.api.DDPClientWraper;
 import chat.rocket.android.api.MethodCallHelper;
+import chat.rocket.android.helper.LogcatIfError;
 import chat.rocket.android.model.ddp.User;
 import chat.rocket.android.realm_helper.RealmHelper;
 import chat.rocket.android.service.Registerable;
@@ -65,7 +66,7 @@ public class CurrentUserObserver extends AbstractModelObserver<User> {
         listeners.add(listener);
       }
       return null;
-    });
+    }).continueWith(new LogcatIfError());
   }
 
   @DebugLog

app/src/main/java/chat/rocket/android/service/observer/NotificationItemObserver.java

+package chat.rocket.android.service.observer;
+
+import android.app.Notification;
+import android.app.PendingIntent;
+import android.content.Context;
+import android.content.Intent;
+import android.graphics.Bitmap;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v4.app.NotificationCompat;
+import android.support.v4.app.NotificationManagerCompat;
+import android.support.v4.content.ContextCompat;
+import bolts.Task;
+import chat.rocket.android.R;
+import chat.rocket.android.activity.MainActivity;
+import chat.rocket.android.api.DDPClientWraper;
+import chat.rocket.android.helper.Avatar;
+import chat.rocket.android.helper.TextUtils;
+import chat.rocket.android.model.ServerConfig;
+import chat.rocket.android.model.internal.NotificationItem;
+import chat.rocket.android.realm_helper.RealmHelper;
+import chat.rocket.android.realm_helper.RealmStore;
+import io.realm.Realm;
+import io.realm.RealmResults;
+import java.util.List;
+
+/**
+ * observes NotificationItem and notify/cancel notification.
+ */
+public class NotificationItemObserver extends AbstractModelObserver<NotificationItem> {
+  public NotificationItemObserver(Context context, String hostname, RealmHelper realmHelper,
+      DDPClientWraper ddpClient) {
+    super(context, hostname, realmHelper, ddpClient);
+  }
+
+  @Override public RealmResults<NotificationItem> queryItems(Realm realm) {
+    return realm.where(NotificationItem.class).findAll();
+  }
+
+  @Override public void onUpdateResults(List<NotificationItem> results) {
+    if (results.isEmpty()) {
+      return;
+    }
+
+    for (NotificationItem item : results) {
+      final String notificationId = item.getRoomId();
+
+      if (item.getUnreadCount() > 0
+          && item.getContentUpdatedAt() > item.getLastSeenAt()) {
+        generateNotificationFor(item)
+            .onSuccess(task -> {
+              Notification notification = task.getResult();
+              if (notification != null) {
+                NotificationManagerCompat.from(context)
+                    .notify(notificationId.hashCode(), notification);
+              }
+              return null;
+            });
+      } else {
+        NotificationManagerCompat.from(context).cancel(notificationId.hashCode());
+      }
+    }
+  }
+
+  private Task<Notification> generateNotificationFor(NotificationItem item) {
+    final String username = item.getSenderName();
+    final String roomId = item.getRoomId();
+    final String title = item.getTitle();
+    final String description = TextUtils.or(item.getDescription(), "").toString();
+    final int unreadCount = item.getUnreadCount();
+
+    if (TextUtils.isEmpty(username)) {
+      return Task.forResult(generateNotification(roomId, title, description, unreadCount, null));
+    }
+
+    int size = context.getResources().getDimensionPixelSize(R.dimen.notification_avatar_size);
+    return new Avatar(hostname, username).getBitmap(context, size)
+        .continueWithTask(task -> {
+          Bitmap icon = task.isFaulted() ? null : task.getResult();
+          final Notification notification =
+              generateNotification(roomId, title, description, unreadCount, icon);
+          return Task.forResult(notification);
+        });
+  }
+
+  private Notification generateNotification(String roomId, String title,
+      @NonNull String description, int unreadCount, @Nullable Bitmap icon) {
+    Intent intent = new Intent(context, MainActivity.class);
+    intent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT | Intent.FLAG_ACTIVITY_CLEAR_TOP);
+    ServerConfig config = RealmStore.getDefault().executeTransactionForRead(realm ->
+        realm.where(ServerConfig.class).equalTo("hostname", hostname).findFirst());
+    if (config != null) {
+      intent.putExtra("serverConfigId", config.getServerConfigId());
+      intent.putExtra("roomId", roomId);
+    }
+
+    PendingIntent pendingIntent = PendingIntent.getActivity(context.getApplicationContext(),
+        (int) (System.currentTimeMillis() % Integer.MAX_VALUE),
+        intent, PendingIntent.FLAG_ONE_SHOT);
+
+    NotificationCompat.Builder builder = new NotificationCompat.Builder(context)
+        .setContentTitle(title)
+        .setContentText(description)
+        .setNumber(unreadCount)
+        .setColor(ContextCompat.getColor(context, R.color.colorPrimary))
+        .setSmallIcon(R.drawable.rocket_chat_notification_24dp)
+        .setContentIntent(pendingIntent);
+
+    if (icon != null) {
+      builder.setLargeIcon(icon);
+    }
+
+    if (description.length() > 20) {
+      return new NotificationCompat.BigTextStyle(builder)
+          .bigText(description)
+          .build();
+    } else {
+      return builder.build();
+    }
+  }
+}

app/src/main/java/chat/rocket/android/service/observer/ReactiveNotificationCancelManager.java

-package chat.rocket.android.service.observer;
-
-import android.content.Context;
-import android.support.v4.app.NotificationManagerCompat;
-import chat.rocket.android.api.DDPClientWraper;
-import chat.rocket.android.model.ddp.RoomSubscription;
-import chat.rocket.android.realm_helper.RealmHelper;
-import hugo.weaving.DebugLog;
-import io.realm.Realm;
-import io.realm.RealmResults;
-import java.util.List;
-
-/**
- * observing room subscriptions with unread>0.
- */
-public class ReactiveNotificationCancelManager extends AbstractModelObserver<RoomSubscription> {
-  public ReactiveNotificationCancelManager(Context context, String hostname,
-      RealmHelper realmHelper, DDPClientWraper ddpClient) {
-    super(context, hostname, realmHelper, ddpClient);
-  }
-
-  @Override public RealmResults<RoomSubscription> queryItems(Realm realm) {
-    return realm.where(RoomSubscription.class)
-        .equalTo("open", true)
-        .equalTo("unread", 0)
-        .findAll();
-  }
-
-  @DebugLog
-  @Override public void onUpdateResults(List<RoomSubscription> roomSubscriptions) {
-    // TODO implement!
-
-    for (RoomSubscription roomSubscription : roomSubscriptions) {
-      final String roomId = roomSubscription.getRid();
-      NotificationManagerCompat.from(context).cancel(roomId.hashCode());
-    }
-  }
-}

app/src/main/java/chat/rocket/android/service/observer/ReactiveNotificationManager.java

 package chat.rocket.android.service.observer;
 
-import android.app.Notification;
-import android.app.PendingIntent;
 import android.content.Context;
-import android.content.Intent;
-import android.support.v4.app.NotificationCompat;
-import android.support.v4.app.NotificationManagerCompat;
-import android.support.v4.content.ContextCompat;
-import chat.rocket.android.R;
-import chat.rocket.android.activity.MainActivity;
 import chat.rocket.android.api.DDPClientWraper;
-import chat.rocket.android.model.ServerConfig;
+import chat.rocket.android.helper.LogcatIfError;
+import chat.rocket.android.log.RCLog;
 import chat.rocket.android.model.ddp.RoomSubscription;
+import chat.rocket.android.model.internal.NotificationItem;
 import chat.rocket.android.realm_helper.RealmHelper;
-import chat.rocket.android.realm_helper.RealmStore;
 import hugo.weaving.DebugLog;
 import io.realm.Realm;
 import io.realm.RealmResults;
 import java.util.List;
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
 
 /**
  * observing room subscriptions with unread>0.
@@ -31,7 +27,6 @@ public class ReactiveNotificationManager extends AbstractModelObserver<RoomSubsc
   @Override public RealmResults<RoomSubscription> queryItems(Realm realm) {
     return realm.where(RoomSubscription.class)
         .equalTo("open", true)
-        .greaterThan("unread", 0)
         .findAll();
   }
 
@@ -39,30 +34,37 @@ public class ReactiveNotificationManager extends AbstractModelObserver<RoomSubsc
   @Override public void onUpdateResults(List<RoomSubscription> roomSubscriptions) {
     // TODO implement!
 
+    JSONArray notifications = new JSONArray();
     for (RoomSubscription roomSubscription : roomSubscriptions) {
       final String roomId = roomSubscription.getRid();
+      NotificationItem item = realmHelper.executeTransactionForRead(realm ->
+          realm.where(NotificationItem.class).equalTo("roomId", roomId).findFirst());
 
-      Intent intent = new Intent(context, MainActivity.class);
-      intent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT | Intent.FLAG_ACTIVITY_CLEAR_TOP);
-      ServerConfig config = RealmStore.getDefault().executeTransactionForRead(realm ->
-          realm.where(ServerConfig.class).equalTo("hostname", hostname).findFirst());
-      if (config != null) {
-        intent.putExtra("serverConfigId", config.getServerConfigId());
-        intent.putExtra("roomId", roomId);
-      }
-
-      PendingIntent pendingIntent = PendingIntent.getActivity(context.getApplicationContext(),
-          (int) (System.currentTimeMillis() % Integer.MAX_VALUE),
-          intent, PendingIntent.FLAG_ONE_SHOT);
+      long lastSeenAt = Math.max(item != null ? item.getLastSeenAt() : 0, roomSubscription.getLs());
+      try {
+        JSONObject notification = new JSONObject()
+            .put("roomId", roomSubscription.getRid())
+            .put("title", roomSubscription.getName())
+            .put("description", "new message")
+            .put("unreadCount", roomSubscription.getUnread())
+            .put("contentUpdatedAt", roomSubscription.get_updatedAt())
+            .put("lastSeenAt", lastSeenAt);
 
-      NotificationCompat.Builder builder = new NotificationCompat.Builder(context)
-          .setContentTitle(roomSubscription.getName())
-          .setColor(ContextCompat.getColor(context, R.color.colorPrimary))
-          .setSmallIcon(R.drawable.rocket_chat_notification_24dp)
-          .setContentIntent(pendingIntent);
+        if (RoomSubscription.TYPE_DIRECT_MESSAGE.equals(roomSubscription.getT())) {
+          notification.put("senderName", roomSubscription.getName());
+        } else {
+          notification.put("senderName", JSONObject.NULL);
+        }
 
-      Notification notification =  builder.build();
-      NotificationManagerCompat.from(context).notify(roomId.hashCode(), notification);
+        notifications.put(notification);
+      } catch (JSONException exception) {
+        RCLog.w(exception);
+      }
     }
+
+    realmHelper.executeTransaction(realm -> {
+      realm.createOrUpdateAllFromJson(NotificationItem.class, notifications);
+      return null;
+    }).continueWith(new LogcatIfError());
   }
 }