Bring back iOS application delegates and fix many issues

SampleGame.iOS/AppDelegate.cs

@@ -0,0 +1,15 @@
+// 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 Foundation;
+using osu.Framework;
+using osu.Framework.iOS;
+
+namespace SampleGame.iOS
+{
+    [Register("AppDelegate")]
+    public class AppDelegate : GameApplicationDelegate
+    {
+        protected override Game CreateGame() => new SampleGameGame();
+    }
+}

SampleGame.iOS/Program.cs

@@ -0,0 +1,15 @@
+// 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 UIKit;
+
+namespace SampleGame.iOS
+{
+    public static class Program
+    {
+        public static void Main(string[] args)
+        {
+            UIApplication.Main(args, null, typeof(AppDelegate));
+        }
+    }
+}

osu.Framework.Templates/templates/template-empty/TemplateGame.iOS/AppDelegate.cs

@@ -0,0 +1,12 @@
+using osu.Framework.iOS;
+using TemplateGame.Game;
+
+namespace TemplateGame.iOS
+{
+    /// <inheritdoc />
+    public class AppDelegate : GameApplicationDelegate
+    {
+        /// <inheritdoc />
+        protected override osu.Framework.Game CreateGame() => new TemplateGameGame();
+    }
+}

osu.Framework.Templates/templates/template-empty/TemplateGame.iOS/Program.cs

@@ -0,0 +1,16 @@
+using UIKit;
+
+namespace TemplateGame.iOS
+{
+    /// <summary>
+    /// </summary>
+    public static class Program
+    {
+        /// <summary>
+        /// </summary>
+        public static void Main(string[] args)
+        {
+            UIApplication.Main(args, null, typeof(AppDelegate));
+        }
+    }
+}

osu.Framework.Templates/templates/template-flappy/FlappyDon.iOS/AppDelegate.cs

@@ -0,0 +1,12 @@
+using FlappyDon.Game;
+using osu.Framework.iOS;
+
+namespace FlappyDon.iOS
+{
+    /// <inheritdoc />
+    public class AppDelegate : GameApplicationDelegate
+    {
+        /// <inheritdoc />
+        protected override osu.Framework.Game CreateGame() => new FlappyDonGame();
+    }
+}

osu.Framework.Templates/templates/template-flappy/FlappyDon.iOS/Program.cs

@@ -0,0 +1,16 @@
+using UIKit;
+
+namespace FlappyDon.iOS
+{
+    /// <summary>
+    /// </summary>
+    public static class Program
+    {
+        /// <summary>
+        /// </summary>
+        public static void Main(string[] args)
+        {
+            UIApplication.Main(args, null, typeof(AppDelegate));
+        }
+    }
+}

osu.Framework.Tests.iOS/AppDelegate.cs

@@ -0,0 +1,14 @@
+// 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 Foundation;
+using osu.Framework.iOS;
+
+namespace osu.Framework.Tests
+{
+    [Register("AppDelegate")]
+    public class AppDelegate : GameApplicationDelegate
+    {
+        protected override Game CreateGame() => new VisualTestGame();
+    }
+}

osu.Framework.Tests.iOS/Program.cs

@@ -0,0 +1,15 @@
+// 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 UIKit;
+
+namespace osu.Framework.Tests
+{
+    public static class Program
+    {
+        public static void Main(string[] args)
+        {
+            UIApplication.Main(args, null, typeof(AppDelegate));
+        }
+    }
+}

osu.Framework.iOS/GameApplication.cs → osu.Framework.iOS/GameApplicationDelegate.cs

@@ -2,48 +2,66 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
-using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using AVFoundation;
 using Foundation;
 using ManagedBass;
 using ManagedBass.Fx;
 using ManagedBass.Mix;
 using SDL;
+using UIKit;
+using static SDL.SDL3;
 
 namespace osu.Framework.iOS
 {
-    public static class GameApplication
+    /// <summary>
+    /// Base <see cref="UIApplicationDelegate"/> implementation for osu!framework applications.
+    /// </summary>
+    public abstract class GameApplicationDelegate : UIApplicationDelegate
     {
-        private const string output_volume = @"outputVolume";
+        internal event Action<string>? DragDrop;
 
-        private static IOSGameHost host = null!;
-        private static Game game = null!;
+        private const string output_volume = "outputVolume";
 
         private static readonly OutputVolumeObserver output_volume_observer = new OutputVolumeObserver();
 
-        public static unsafe void Main(Game target)
-        {
-            NativeLibrary.SetDllImportResolver(typeof(Bass).Assembly, (_, assembly, path) => NativeLibrary.Load("@rpath/bass.framework/bass", assembly, path));
-            NativeLibrary.SetDllImportResolver(typeof(BassFx).Assembly, (_, assembly, path) => NativeLibrary.Load("@rpath/bass_fx.framework/bass_fx", assembly, path));
-            NativeLibrary.SetDllImportResolver(typeof(BassMix).Assembly, (_, assembly, path) => NativeLibrary.Load("@rpath/bassmix.framework/bassmix", assembly, path));
-            NativeLibrary.SetDllImportResolver(typeof(SDL3).Assembly, (_, assembly, path) => NativeLibrary.Load("@rpath/SDL3.framework/SDL3", assembly, path));
+        private IOSGameHost host = null!;
 
-            game = target;
+        public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
+        {
+            mapLibraryNames();
 
-            SDL3.SDL_RunApp(0, null, &main, IntPtr.Zero);
-        }
+            SDL_SetMainReady();
+            SDL_SetiOSEventPump(true);
 
-        [UnmanagedCallersOnly(CallConvs = new[] { typeof(CallConvCdecl) })]
-        private static unsafe int main(int argc, byte** argv)
-        {
             var audioSession = AVAudioSession.SharedInstance();
             audioSession.AddObserver(output_volume_observer, output_volume, NSKeyValueObservingOptions.New, 0);
 
             host = new IOSGameHost();
-            host.Run(game);
+            host.Run(CreateGame());
+            return true;
+        }
 
-            return 0;
+        public override bool OpenUrl(UIApplication application, NSUrl url, string sourceApplication, NSObject annotation)
+        {
+            // copied verbatim from SDL: https://github.com/libsdl-org/SDL/blob/d252a8fe126b998bd1b0f4e4cf52312cd11de378/src/video/uikit/SDL_uikitappdelegate.m#L508-L535
+            // the hope is that the SDL app delegate class does not have such handling exist there, but Apple does not provide a corresponding notification to make that possible.
+            NSUrl? fileUrl = url.FilePathUrl;
+            DragDrop?.Invoke(fileUrl != null ? fileUrl.Path! : url.AbsoluteString!);
+            return true;
+        }
+
+        /// <summary>
+        /// Creates the <see cref="Game"/> class to launch.
+        /// </summary>
+        protected abstract Game CreateGame();
+
+        private static void mapLibraryNames()
+        {
+            NativeLibrary.SetDllImportResolver(typeof(Bass).Assembly, (_, assembly, path) => NativeLibrary.Load("@rpath/bass.framework/bass", assembly, path));
+            NativeLibrary.SetDllImportResolver(typeof(BassFx).Assembly, (_, assembly, path) => NativeLibrary.Load("@rpath/bass_fx.framework/bass_fx", assembly, path));
+            NativeLibrary.SetDllImportResolver(typeof(BassMix).Assembly, (_, assembly, path) => NativeLibrary.Load("@rpath/bassmix.framework/bassmix", assembly, path));
+            NativeLibrary.SetDllImportResolver(typeof(SDL3).Assembly, (_, assembly, path) => NativeLibrary.Load("@rpath/SDL3.framework/SDL3", assembly, path));
         }
 
         private class OutputVolumeObserver : NSObject

osu.Framework.iOS/IOSWindow.cs

@@ -47,6 +47,9 @@ public override void Create()
 
             uiWindow = Runtime.GetNSObject<UIWindow>(WindowHandle);
             updateSafeArea();
+
+            var appDelegate = (GameApplicationDelegate)UIApplication.SharedApplication.Delegate;
+            appDelegate.DragDrop += TriggerDragDrop;
         }
 
         protected override unsafe void RunMainLoop()
@@ -59,8 +62,6 @@ protected override unsafe void RunMainLoop()
             // iOS may be a good forward direction if this ever comes up, as a user may see a potentially higher
             // frame rate with multi-threaded mode turned on, but it is going to give them worse input latency
             // and higher power usage.
-
-            SDL_SetiOSEventPump(false);
             SDL_SetiOSAnimationCallback(SDLWindowHandle, 1, &runFrame, ObjectHandle.Handle);
         }
 

osu.Framework/Platform/SDL3/SDL3Window.cs

@@ -666,6 +666,8 @@ internal virtual void SetIconFromGroup(IconGroup iconGroup)
         /// </summary>
         public event Action<string>? DragDrop;
 
+        protected void TriggerDragDrop(string filename) => DragDrop?.Invoke(filename);
+
         #endregion
 
         public void Dispose()

osu.Framework/Platform/SDL3/SDL3Window_Input.cs

@@ -217,7 +217,7 @@ private void handleDropEvent(SDL_DropEvent evtDrop)
                 case SDL_EventType.SDL_EVENT_DROP_FILE:
                     string? str = evtDrop.GetData();
                     if (str != null)
-                        DragDrop?.Invoke(str);
+                        TriggerDragDrop(str);
 
                     break;
             }