Add window titles to main and compose scenes

Tusker/Scenes/ComposeSceneDelegate.swift

@@ -7,11 +7,14 @@
 //
 
 import UIKit
+import Combine
 
 class ComposeSceneDelegate: UIResponder, UIWindowSceneDelegate {
 
     var window: UIWindow?
     
+    private var cancellables = Set<AnyCancellable>()
+    
     func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
         guard let windowScene = scene as? UIWindowScene else {
             return
@@ -56,6 +59,11 @@ class ComposeSceneDelegate: UIResponder, UIWindowSceneDelegate {
         composeVC.delegate = self
         let nav = EnhancedNavigationViewController(rootViewController: composeVC)
         
+        updateTitle(draft: composeVC.draft)
+        composeVC.uiState.$draft
+            .sink { [unowned self] in self.updateTitle(draft: $0) }
+            .store(in: &cancellables)
+        
         window = UIWindow(windowScene: windowScene)
         window!.rootViewController = nav
         window!.makeKeyAndVisible()
@@ -78,6 +86,19 @@ class ComposeSceneDelegate: UIResponder, UIWindowSceneDelegate {
         return scene.userActivity
     }
     
+    private func updateTitle(draft: Draft) {
+        guard let scene = window?.windowScene,
+              let mastodonController = scene.session.mastodonController else {
+            return
+        }
+        if let inReplyToID = draft.inReplyToID,
+           let inReplyTo = mastodonController.persistentContainer.status(for: inReplyToID) {
+            scene.title = "Reply to @\(inReplyTo.account.acct)"
+        } else {
+            scene.title = "New Post"
+        }
+    }
+    
     @objc private func themePrefChanged() {
         window?.overrideUserInterfaceStyle = Preferences.shared.theme
     }

Tusker/Scenes/MainSceneDelegate.swift

@@ -185,6 +185,15 @@ class MainSceneDelegate: UIResponder, UIWindowSceneDelegate, TuskerSceneDelegate
         LocalData.shared.setMostRecentAccount(account)
         window!.windowScene!.session.mastodonController = MastodonController.getForAccount(account)
         
+        // iPadOS shows the title below the App Name
+        // macOS uses the title as the window title, but uses the subtitle in addition to the default window title (the app name)
+        // so this way we get basically the same behavior on both
+        if ProcessInfo.processInfo.isiOSAppOnMac || ProcessInfo.processInfo.isMacCatalystApp {
+            window!.windowScene!.subtitle = account.instanceURL.host!
+        } else {
+            window!.windowScene!.title = account.instanceURL.host!
+        }
+        
         let newRoot = createAppUI()
         if let container = window?.rootViewController as? AccountSwitchingContainerViewController {
             let direction: AccountSwitchingContainerViewController.AnimationDirection