Add support for presenting/opening files on iOS

osu.Framework.iOS/IOSFilePresenter.cs

@@ -0,0 +1,61 @@
+// Copyright (c) ppy Pty Ltd <[email protected]>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+using System.IO;
+using Foundation;
+using UIKit;
+using UniformTypeIdentifiers;
+
+namespace osu.Framework.iOS
+{
+    internal class IOSFilePresenter : UIDocumentInteractionControllerDelegate
+    {
+        private readonly IOSWindow window;
+        private readonly UIDocumentInteractionController viewController = new UIDocumentInteractionController();
+
+        internal IOSFilePresenter(IOSWindow window)
+        {
+            this.window = window;
+        }
+
+        public bool OpenFile(string filename)
+        {
+            setupViewController(filename);
+
+            if (viewController.PresentPreview(true))
+                return true;
+
+            var gameView = window.UIWindow.RootViewController!.View!;
+            return viewController.PresentOpenInMenu(gameView.Bounds, gameView, true);
+        }
+
+        public bool PresentFile(string filename)
+        {
+            setupViewController(filename);
+
+            var gameView = window.UIWindow.RootViewController!.View!;
+            return viewController.PresentOptionsMenu(gameView.Bounds, gameView, true);
+        }
+
+        private void setupViewController(string filename)
+        {
+            var url = NSUrl.FromFilename(filename);
+
+            viewController.Url = url;
+            viewController.Delegate = this;
+
+            if (OperatingSystem.IsIOSVersionAtLeast(14))
+                viewController.Uti = UTType.CreateFromExtension(Path.GetExtension(filename))?.Identifier ?? UTTypes.Data.Identifier;
+        }
+
+        public override UIViewController ViewControllerForPreview(UIDocumentInteractionController controller) => window.UIWindow.RootViewController!;
+
+        public override void WillBeginSendingToApplication(UIDocumentInteractionController controller, string? application)
+        {
+            // this path is triggered when a user opens the presented document in another application,
+            // the menu does not dismiss afterward and locks the game indefinitely. dismiss it manually.
+            viewController.DismissMenu(true);
+        }
+    }
+}

osu.Framework.iOS/IOSGameHost.cs

@@ -23,12 +23,19 @@ namespace osu.Framework.iOS
 {
     public class IOSGameHost : SDLGameHost
     {
+        private IOSFilePresenter presenter = null!;
+
         public IOSGameHost()
             : base(string.Empty)
         {
         }
 
-        protected override IWindow CreateWindow(GraphicsSurfaceType preferredSurface) => new IOSWindow(preferredSurface, Options.FriendlyGameName);
+        protected override IWindow CreateWindow(GraphicsSurfaceType preferredSurface)
+        {
+            var window = new IOSWindow(preferredSurface, Options.FriendlyGameName);
+            presenter = new IOSFilePresenter(window);
+            return window;
+        }
 
         protected override void SetupConfig(IDictionary<FrameworkSetting, object> defaultOverrides)
         {
@@ -42,9 +49,9 @@ protected override void SetupConfig(IDictionary<FrameworkSetting, object> defaul
 
         public override Storage GetStorage(string path) => new IOSStorage(path, this);
 
-        public override bool OpenFileExternally(string filename) => false;
+        public override bool OpenFileExternally(string filename) => presenter.OpenFile(filename);
 
-        public override bool PresentFileExternally(string filename) => false;
+        public override bool PresentFileExternally(string filename) => presenter.PresentFile(filename);
 
         public override void OpenUrlExternally(string url)
         {

osu.Framework.iOS/IOSWindow.cs

@@ -18,7 +18,9 @@ namespace osu.Framework.iOS
 {
     internal class IOSWindow : SDL3MobileWindow
     {
-        private UIWindow? window;
+        private UIWindow? uiWindow;
+
+        public UIWindow UIWindow => uiWindow!;
 
         public override Size Size
         {
@@ -27,7 +29,7 @@ protected set
             {
                 base.Size = value;
 
-                if (window != null)
+                if (uiWindow != null)
                     updateSafeArea();
             }
         }
@@ -43,7 +45,7 @@ public override void Create()
 
             base.Create();
 
-            window = Runtime.GetNSObject<UIWindow>(WindowHandle);
+            uiWindow = Runtime.GetNSObject<UIWindow>(WindowHandle);
             updateSafeArea();
         }
 
@@ -73,14 +75,14 @@ private static void runFrame(IntPtr userdata)
 
         private void updateSafeArea()
         {
-            Debug.Assert(window != null);
+            Debug.Assert(uiWindow != null);
 
             SafeAreaPadding.Value = new MarginPadding
             {
-                Top = (float)window.SafeAreaInsets.Top * Scale,
-                Left = (float)window.SafeAreaInsets.Left * Scale,
-                Bottom = (float)window.SafeAreaInsets.Bottom * Scale,
-                Right = (float)window.SafeAreaInsets.Right * Scale,
+                Top = (float)uiWindow.SafeAreaInsets.Top * Scale,
+                Left = (float)uiWindow.SafeAreaInsets.Left * Scale,
+                Bottom = (float)uiWindow.SafeAreaInsets.Bottom * Scale,
+                Right = (float)uiWindow.SafeAreaInsets.Right * Scale,
             };
         }
     }