message manager updates badge count

// FREEBIE

src/Messages/TSMessagesManager.m

@@ -115,9 +115,24 @@ NS_ASSUME_NONNULL_BEGIN
 
     OWSSingletonAssert();
 
+    [self startObserving];
+
     return self;
 }
 
+- (void)startObserving
+{
+    [[NSNotificationCenter defaultCenter] addObserver:self
+                                             selector:@selector(yapDatabaseModified:)
+                                                 name:YapDatabaseModifiedNotification
+                                               object:nil];
+}
+
+- (void)yapDatabaseModified:(NSNotification *)notification
+{
+    [self updateApplicationBadgeCount];
+}
+
 #pragma mark - Debugging
 
 - (NSString *)descriptionForEnvelope:(OWSSignalServiceProtosEnvelope *)envelope
@@ -1068,6 +1083,12 @@ NS_ASSUME_NONNULL_BEGIN
     return numberOfItems;
 }
 
+- (void)updateApplicationBadgeCount
+{
+    NSUInteger numberOfItems = [self unreadMessagesCount];
+    [[UIApplication sharedApplication] setApplicationIconBadgeNumber:numberOfItems];
+}
+
 - (NSUInteger)unreadMessagesInThread:(TSThread *)thread {
     __block NSUInteger numberOfItems;
     [self.dbConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {