Open a new window when clicking on a tag on macOS

Gallery/Base.lproj/Main.storyboard

@@ -27,7 +27,7 @@
         <!--Home-->
         <scene sceneID="tne-QT-ifu">
             <objects>
-                <viewController id="BYZ-38-t0r" customClass="HomeViewController" customModule="Gallery" customModuleProvider="target" sceneMemberID="viewController">
+                <viewController storyboardIdentifier="HomeViewController" id="BYZ-38-t0r" customClass="HomeViewController" customModule="Gallery" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" contentMode="scaleToFill" id="8bC-Xf-vdC">
                         <rect key="frame" x="0.0" y="0.0" width="800" height="600"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>

Gallery/EditTagsViewController.swift

@@ -70,6 +70,32 @@ class EditTagsViewController: UIViewController, UITableViewDelegate, UITableView
             newViewController.tag = (post?.tags![index!.row] as! Tag).name
         }
     }
+    
+    override func shouldPerformSegue(withIdentifier identifier: String, sender: Any?) -> Bool {
+        if identifier == "showTag" {
+            #if targetEnvironment(macCatalyst)
+            guard let cell = sender as? TagViewCell else {
+                return false
+            }
+            
+            guard let name = cell.label.text else {
+                return false
+            }
+            
+            let activity = NSUserActivity(activityType: "postsOf")
+            activity.userInfo = ["tags": name]
+            activity.isEligibleForHandoff = true
+            
+            UIApplication.shared.requestSceneSessionActivation(nil, userActivity: activity, options: nil, errorHandler: nil)
+            
+            return false
+            #else
+            return true
+            #endif
+        }
+        
+        return super.shouldPerformSegue(withIdentifier: identifier, sender: sender)
+    }
 }
 
 extension EditTagsViewController {

Gallery/HomeViewController.swift

@@ -8,7 +8,14 @@ class HomeViewController: UIViewController, UIDocumentPickerDelegate {
     
     let documentsPath : URL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0].absoluteURL
     
-    let windowTitle = "Home"
+    var tags: String?
+    
+    func updateWindowTitle() {
+        let windowTitle = tags ?? "All Posts"
+        
+        self.view.window?.windowScene!.title = windowTitle
+        navigationItem.title = windowTitle
+    }
     
     func importFile(path: URL) {
         guard let appDelegate =
@@ -54,13 +61,9 @@ class HomeViewController: UIViewController, UIDocumentPickerDelegate {
     override func viewWillAppear(_ animated: Bool) {
         super.viewWillAppear(animated)
                 
-        collectionManager = PostsManager(collectionView: collectionView, tag: nil)
+        collectionManager = PostsManager(collectionView: collectionView, tag: tags)
-    }
         
-    override func viewDidAppear(_ animated: Bool) {
+        updateWindowTitle()
-        super.viewDidAppear(animated)
-        
-        self.view.window?.windowScene!.title = windowTitle
     }
     
     @IBAction func importAction(_ sender: Any) {
@@ -113,3 +116,10 @@ class HomeViewController: UIViewController, UIDocumentPickerDelegate {
         return super.shouldPerformSegue(withIdentifier: identifier, sender: sender)
     }
 }
+
+extension HomeViewController {
+    static func loadFromStoryboard() -> HomeViewController? {
+        let storyboard = UIStoryboard(name: "Main", bundle: .main)
+        return storyboard.instantiateViewController(withIdentifier: "HomeViewController") as? HomeViewController
+    }
+}

Gallery/PostDetailViewController.swift

@@ -64,17 +64,7 @@ class PostDetailViewController: UIViewController, UIPopoverPresentationControlle
             }
         }
             
-        #if !targetEnvironment(macCatalyst)
         updateWindowTitle()
-        #endif
-    }
-    
-    override func viewDidAppear(_ animated: Bool) {
-        super.viewDidAppear(animated)
-        
-        #if targetEnvironment(macCatalyst)
-        updateWindowTitle()
-        #endif
     }
     
     @objc func closePopup() {

Gallery/PostsManager.swift

@@ -110,7 +110,7 @@ class PostsManager: NSObject, UICollectionViewDataSource, UICollectionViewDelega
         
         managedContext = appDelegate.persistentContainer.viewContext
         
-        setTag(tag: nil)
+        setTag(tag: tag)
     }
     
     func reload(request: NSFetchRequest<NSManagedObject>) {

Gallery/SceneDelegate.swift

@@ -51,6 +51,14 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
         return nil
     }
     
+    func getTagsFromActivity(activity: NSUserActivity ) -> String? {
+        if let photoID = activity.userInfo?["tags"] as? String {
+           return photoID
+        }
+        
+        return nil
+    }
+    
     func configure(window: UIWindow?, with activity: NSUserActivity) -> Bool {
         if activity.activityType == "post" {
             if let post = getPostFromActivity(activity: activity) {
@@ -73,6 +81,18 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
                     if let navigationController = window?.rootViewController as? UINavigationController {
                         navigationController.pushViewController(editTagsController, animated: false)
                         
+                        return true
+                    }
+                }
+            }
+        } else if activity.activityType == "postsOf" {
+            if let tags = getTagsFromActivity(activity: activity) {
+                if let homeController = HomeViewController.loadFromStoryboard() {
+                    homeController.tags = tags
+                    
+                    if let navigationController = window?.rootViewController as? UINavigationController {
+                        navigationController.pushViewController(homeController, animated: false)
+                        
                         return true
                     }
                 }