Update cells when statuses/accounts change from other sources

Tusker/MastodonCache.swift

@@ -7,6 +7,7 @@
 //
 
 import Foundation
+import Combine
 import Pachyderm
 
 class MastodonCache {
@@ -16,6 +17,9 @@ class MastodonCache {
     private static var relationships = [String: Relationship]()
     private static var notifications = [String: Pachyderm.Notification]()
     
+    static let statusSubject = PassthroughSubject<Status, Never>()
+    static let accountSubject = PassthroughSubject<Account, Never>()
+
     // MARK: - Statuses
     static func status(for id: String) -> Status? {
         return statuses[id]
@@ -28,6 +32,8 @@ class MastodonCache {
             add(status: reblog)
             add(account: reblog.account)
         }
+        
+        statusSubject.send(status)
     }
     
     static func status(for id: String, completion: @escaping (Status?) -> Void) {
@@ -57,6 +63,7 @@ class MastodonCache {
     
     static func set(account: Account, for id: String) {
         accounts[id] = account
+        accountSubject.send(account)
     }
     
     static func account(for id: String, completion: @escaping (Account?) -> Void) {

Tusker/Screens/Conversation/ConversationTableViewController.swift

@@ -116,12 +116,12 @@ class ConversationTableViewController: EnhancedTableViewController {
         if statusID == mainStatusID {
             guard let cell = tableView.dequeueReusableCell(withIdentifier: "mainStatusCell", for: indexPath) as? ConversationMainStatusTableViewCell else { fatalError() }
             cell.selectionStyle = .none
-            cell.updateUI(for: statusID)
+            cell.updateUI(statusID: statusID)
             cell.delegate = self
             return cell
         } else {
             guard let cell = tableView.dequeueReusableCell(withIdentifier: "statusCell", for: indexPath) as? StatusTableViewCell else { fatalError() }
-            cell.updateUI(for: statusID)
+            cell.updateUI(statusID: statusID)
             cell.delegate = self
             return cell
         }

Tusker/Screens/Notifications/NotificationsTableViewController.swift

@@ -92,8 +92,7 @@ class NotificationsTableViewController: EnhancedTableViewController {
         switch notification.kind {
         case .mention:
             guard let cell = tableView.dequeueReusableCell(withIdentifier: "statusCell", for: indexPath) as? StatusTableViewCell else { fatalError() }
-            let status = notification.status!
+            cell.updateUI(statusID: notification.status!.id)
-            cell.updateUI(for: status.id)
             cell.delegate = self
             return cell
         case .favourite, .reblog:

Tusker/Screens/Profile/ProfileTableViewController.swift

@@ -183,8 +183,7 @@ class ProfileTableViewController: EnhancedTableViewController, PreferencesAdapti
             return cell
         case 1:
             guard let cell = tableView.dequeueReusableCell(withIdentifier: "statusCell", for: indexPath) as? StatusTableViewCell else { fatalError() }
-            let statusID = statusIDs[indexPath.row]
+            cell.updateUI(statusID: statusIDs[indexPath.row])
-            cell.updateUI(for: statusID)
             cell.delegate = self
             return cell
         default:

Tusker/Screens/Timeline/TimelineTableViewController.swift

@@ -102,7 +102,7 @@ class TimelineTableViewController: EnhancedTableViewController {
     override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
         guard let cell = tableView.dequeueReusableCell(withIdentifier: "statusCell", for: indexPath) as? StatusTableViewCell else { fatalError() }
 
-        cell.updateUI(for: statusID(for: indexPath))
+        cell.updateUI(statusID: statusID(for: indexPath))
         cell.delegate = self
 
         return cell

Tusker/Views/Status/ConversationMainStatusTableViewCell.swift

@@ -7,6 +7,7 @@
 //
 
 import UIKit
+import Combine
 import Pachyderm
 
 class ConversationMainStatusTableViewCell: UITableViewCell, PreferencesAdaptive {
@@ -47,6 +48,14 @@ class ConversationMainStatusTableViewCell: UITableViewCell, PreferencesAdaptive
     var avatarURL: URL?
     var updateTimestampWorkItem: DispatchWorkItem?
     
+    var statusUpdater: Cancellable?
+    var accountUpdater: Cancellable?
+    
+    deinit {
+        statusUpdater?.cancel()
+        accountUpdater?.cancel()
+    }
+    
     override func awakeFromNib() {
         displayNameLabel.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(accountPressed)))
         usernameLabel.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(accountPressed)))
@@ -55,6 +64,16 @@ class ConversationMainStatusTableViewCell: UITableViewCell, PreferencesAdaptive
         attachmentsView.delegate = self
         attachmentsView.layer.cornerRadius = 5
         attachmentsView.layer.masksToBounds = true
+        
+        statusUpdater = MastodonCache.statusSubject
+            .filter { $0.id == self.statusID }
+            .receive(on: DispatchQueue.main)
+            .sink(receiveValue: updateStatusState(status:))
+        
+        accountUpdater = MastodonCache.accountSubject
+            .filter { $0.id == self.accountID }
+            .receive(on: DispatchQueue.main)
+            .sink(receiveValue: updateUI(account:))
     }
     
     func updateUIForPreferences() {
@@ -64,11 +83,11 @@ class ConversationMainStatusTableViewCell: UITableViewCell, PreferencesAdaptive
         displayNameLabel.text = account.realDisplayName
     }
     
-    func updateUI(for statusID: String) {
+    func updateUI(statusID: String) {
-        self.statusID = statusID
-        
         guard let status = MastodonCache.status(for: statusID) else { fatalError("Missing cached status \(statusID)") }
         
+        self.statusID = status.id
+        
         let account: Account
         if let reblog = status.reblog {
             account = reblog.account
@@ -76,9 +95,25 @@ class ConversationMainStatusTableViewCell: UITableViewCell, PreferencesAdaptive
             account = status.account
         }
         self.accountID = account.id
-        
+        updateUI(account: account)
         updateUIForPreferences()
         
+        updateTimestamp()
+        
+        attachmentsView.updateUI(status: status)
+
+        let realStatus = status.reblog ?? status
+        updateStatusState(status: realStatus)
+
+        contentLabel.statusID = statusID
+    }
+    
+    private func updateStatusState(status: Status) {
+        favorited = status.favourited ?? false
+        reblogged = status.reblogged ?? false
+    }
+    
+    private func updateUI(account: Account) {
         usernameLabel.text = "@\(account.acct)"
         avatarImageView.image = nil
         avatarURL = account.avatar
@@ -89,15 +124,6 @@ class ConversationMainStatusTableViewCell: UITableViewCell, PreferencesAdaptive
                 self.avatarURL = nil
             }
         }
-        updateTimestamp()
-        
-        attachmentsView.updateUI(status: status)
-
-        let realStatus = status.reblog ?? status
-        favorited = realStatus.favourited ?? false
-        reblogged = realStatus.reblogged ?? false
-        
-        contentLabel.statusID = statusID
     }
     
     func updateTimestamp() {

Tusker/Views/Status/StatusTableViewCell.swift

@@ -7,6 +7,7 @@
 //
 
 import UIKit
+import Combine
 import Pachyderm
 
 protocol StatusTableViewCellDelegate: TuskerNavigationDelegate {    
@@ -50,6 +51,16 @@ class StatusTableViewCell: UITableViewCell, PreferencesAdaptive {
     var updateTimestampWorkItem: DispatchWorkItem?
     var attachmentDataTasks: [URLSessionDataTask] = []
     
+    var statusUpdater: Cancellable?
+    var accountUpdater: Cancellable?
+    var rebloggerAccountUpdater: Cancellable?
+
+    deinit {
+        statusUpdater?.cancel()
+        accountUpdater?.cancel()
+        rebloggerAccountUpdater?.cancel()
+    }
+    
     override func awakeFromNib() {
         displayNameLabel.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(accountPressed)))
         usernameLabel.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(accountPressed)))
@@ -59,6 +70,24 @@ class StatusTableViewCell: UITableViewCell, PreferencesAdaptive {
         attachmentsView.delegate = self
         attachmentsView.layer.cornerRadius = 5
         attachmentsView.layer.masksToBounds = true
+        
+        statusUpdater = MastodonCache.statusSubject
+            .filter { $0.id == self.statusID || $0.id == self.reblogStatusID }
+            .receive(on: DispatchQueue.main)
+            .sink(receiveValue: updateStatusState(status:))
+        
+        accountUpdater = MastodonCache.accountSubject
+            .filter { $0.id == self.accountID }
+            .receive(on: DispatchQueue.main)
+            .sink(receiveValue: updateUI(account:))
+        
+        rebloggerAccountUpdater = MastodonCache.accountSubject
+            .filter { $0.id == self.rebloggerID }
+            .receive(on: DispatchQueue.main)
+            .sink(receiveValue: { (_) in
+                // this method is responsible for setting the reblog label text
+                self.updateUIForPreferences()
+            })
     }
 
     func updateUIForPreferences() {
@@ -71,8 +100,9 @@ class StatusTableViewCell: UITableViewCell, PreferencesAdaptive {
         displayNameLabel.text = account.realDisplayName
     }
 
-    func updateUI(for statusID: String) {
+    func updateUI(statusID: String) {
         guard var status = MastodonCache.status(for: statusID) else { fatalError("Missing cached status \(statusID)") }
+        self.statusID = statusID
         
         if let reblogID = status.reblog?.id,
             let reblog = MastodonCache.status(for: reblogID) {
@@ -87,10 +117,26 @@ class StatusTableViewCell: UITableViewCell, PreferencesAdaptive {
         }
         let account = status.account
         self.accountID = account.id
-        self.statusID = status.id
+        updateUI(account: account)
 
         updateUIForPreferences()
 
+        updateTimestamp()
+
+        attachmentsView.updateUI(status: status)
+
+        let realStatus = status.reblog ?? status
+        updateStatusState(status: realStatus)
+
+        contentLabel.statusID = status.id
+    }
+    
+    private func updateStatusState(status: Status) {
+        favorited = status.favourited ?? false
+        reblogged = status.reblogged ?? false
+    }
+    
+    private func updateUI(account: Account) {
         usernameLabel.text = "@\(account.acct)"
         avatarImageView.image = nil
         avatarURL = account.avatar
@@ -101,15 +147,6 @@ class StatusTableViewCell: UITableViewCell, PreferencesAdaptive {
                 self.avatarURL = nil
             }
         }
-        updateTimestamp()
-        
-        attachmentsView.updateUI(status: status)
-
-        let realStatus = status.reblog ?? status
-        favorited = realStatus.favourited ?? false
-        reblogged = realStatus.reblogged ?? false
-        
-        contentLabel.statusID = status.id
     }
     
     func updateTimestamp() {
@@ -247,7 +284,6 @@ extension StatusTableViewCell: TableViewSwipeActionProvider {
                     }
                     completion(true)
                     MastodonCache.add(status: status)
-                    self.updateUI(for: self.reblogStatusID ?? self.statusID)
                 }
             })
         }
@@ -275,7 +311,6 @@ extension StatusTableViewCell: TableViewSwipeActionProvider {
                     }
                     completion(true)
                     MastodonCache.add(status: status)
-                    self.updateUI(for: self.reblogStatusID ?? self.statusID)
                 }
             })
         }