Handle unread count change notifications in Folder. Update the unread count when needed.

Frameworks/Account/Account.swift

@@ -290,8 +290,8 @@ public final class Account: DisplayNameProvider, UnreadCountProvider, Container,
 	
 	@objc func unreadCountDidChange(_ note: Notification) {
 
-		if let object = note.object as? AnyObject {
-			if objectIsChild(object) {
+		if let object = note.object {
+			if objectIsChild(object as AnyObject) {
 				updateUnreadCount()
 			}
 		}

Frameworks/Account/Folder.swift

@@ -48,6 +48,8 @@ public final class Folder: DisplayNameProvider, Container, UnreadCountProvider {
 		
 		self.account = account
 		self.name = name
+
+		NotificationCenter.default.addObserver(self, selector: #selector(unreadCountDidChange(_:)), name: .UnreadCountDidChange, object: nil)
 	}
 
 	// MARK: - Disk Dictionary
@@ -116,12 +118,29 @@ public final class Folder: DisplayNameProvider, Container, UnreadCountProvider {
 		children += [feed]
 		return true
 	}
+
+	// MARK: Notifications
+
+	@objc func unreadCountDidChange(_ note: Notification) {
+
+		if let object = note.object {
+			if objectIsChild(object as AnyObject) {
+				updateUnreadCount()
+			}
+		}
+	}
+
 }
 
 // MARK: - Private
 
 private extension Folder {
 
+	func updateUnreadCount() {
+		
+		unreadCount = calculateUnreadCount(children)
+	}
+
 	func childrenContainsFeed(_ feed: Feed) -> Bool {
 		
 		return children.contains(where: { (object) -> Bool in