Take focus from game during calls on iOS

osu.Framework.Tests/Visual/Platform/TestSceneActiveState.cs

@@ -9,6 +9,7 @@
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
 using osu.Framework.Graphics.Sprites;
+using osu.Framework.Logging;
 using osu.Framework.Platform;
 using osuTK.Graphics;
 
@@ -49,7 +50,12 @@ protected override void LoadComplete()
                 },
             };
 
-            isActive.BindValueChanged(active => isActiveBox.Colour = active.NewValue ? Color4.Green : Color4.Red, true);
+            isActive.BindValueChanged(active =>
+            {
+                Logger.Log($"Game activity changed from {active.OldValue} to {active.NewValue}");
+                isActiveBox.Colour = active.NewValue ? Color4.Green : Color4.Red;
+            }, true);
+
             cursorInWindow?.BindValueChanged(active => cursorInWindowBox.Colour = active.NewValue ? Color4.Green : Color4.Red, true);
         }
 

osu.Framework.iOS/IOSCallObserver.cs

@@ -0,0 +1,41 @@
+// 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.Linq;
+using CallKit;
+using Foundation;
+
+namespace osu.Framework.iOS
+{
+    internal class IOSCallObserver : NSObject, ICXCallObserverDelegate
+    {
+        public event Action? OnCall;
+        public event Action? OnCallEnded;
+
+        private readonly CXCallController callController;
+
+        public IOSCallObserver()
+        {
+            callController = new CXCallController();
+            callController.CallObserver.SetDelegate(this, null);
+
+            if (callController.CallObserver.Calls.Any(c => !c.HasEnded))
+                OnCall?.Invoke();
+        }
+
+        public void CallChanged(CXCallObserver callObserver, CXCall call)
+        {
+            if (!call.HasEnded)
+                OnCall?.Invoke();
+            else
+                OnCallEnded?.Invoke();
+        }
+
+        protected override void Dispose(bool disposing)
+        {
+            callController.Dispose();
+            base.Dispose(disposing);
+        }
+    }
+}

osu.Framework.iOS/IOSWindow.cs

@@ -10,8 +10,8 @@
 using osu.Framework.Graphics;
 using osu.Framework.Platform;
 using osu.Framework.Platform.SDL3;
-using static SDL.SDL3;
 using UIKit;
+using static SDL.SDL3;
 
 namespace osu.Framework.iOS
 {
@@ -21,6 +21,8 @@ internal class IOSWindow : SDL3MobileWindow, IIOSWindow
 
         public UIViewController ViewController => UIWindow.RootViewController!;
 
+        private IOSCallObserver? callObserver;
+
         public override Size Size
         {
             get => base.Size;
@@ -47,8 +49,31 @@ public override void Create()
 
             var appDelegate = (GameApplicationDelegate)UIApplication.SharedApplication.Delegate;
             appDelegate.DragDrop += TriggerDragDrop;
+
+            // osu! cannot operate when a call takes place, as the audio is completely cut from the game, making it behave in unexpected manner.
+            // while this is o!f code, it's simpler to do this here rather than in osu!.
+            // we can reconsider this if there are framework consumers which find this behaviour undesirable.
+            callObserver = new IOSCallObserver();
+            callObserver.OnCall += onCall;
+            callObserver.OnCallEnded += onCallEnded;
+        }
+
+        private bool inCall;
+
+        private void onCall()
+        {
+            inCall = true;
+            UpdateActiveState();
         }
 
+        private void onCallEnded()
+        {
+            inCall = false;
+            UpdateActiveState();
+        }
+
+        protected override bool ShouldBeActive => base.ShouldBeActive && !inCall;
+
         protected override unsafe void RunMainLoop()
         {
             // Delegate running the main loop to CADisplayLink.
@@ -62,6 +87,12 @@ protected override unsafe void RunMainLoop()
             SDL_SetiOSAnimationCallback(SDLWindowHandle, 1, &runFrame, ObjectHandle.Handle);
         }
 
+        public override void Dispose()
+        {
+            base.Dispose();
+            callObserver?.Dispose();
+        }
+
         [UnmanagedCallersOnly(CallConvs = new[] { typeof(CallConvCdecl) })]
         private static void runFrame(IntPtr userdata)
         {

osu.Framework/Platform/SDL3/SDL3Window.cs

@@ -676,7 +676,7 @@ internal virtual void SetIconFromGroup(IconGroup iconGroup)
 
         #endregion
 
-        public void Dispose()
+        public virtual void Dispose()
         {
             Close();
             SDL_Quit();

osu.Framework/Platform/SDL3/SDL3Window_Windowing.cs

@@ -122,22 +122,10 @@ private void initialiseWindowingAfterCreation()
             WindowMode.TriggerChange();
         }
 
-        private bool focused;
-
         /// <summary>
         /// Whether the window currently has focus.
         /// </summary>
-        public bool Focused
-        {
-            get => focused;
-            protected set
-            {
-                if (value == focused)
-                    return;
-
-                isActive.Value = focused = value;
-            }
-        }
+        public bool Focused { get; private set; }
 
         public WindowMode DefaultWindowMode => RuntimeInfo.IsMobile ? Configuration.WindowMode.Fullscreen : Configuration.WindowMode.Windowed;
 
@@ -222,9 +210,17 @@ public Size MaxSize
         /// </summary>
         public Bindable<WindowMode> WindowMode { get; } = new Bindable<WindowMode>();
 
+        public IBindable<bool> IsActive => isActive;
+
         private readonly BindableBool isActive = new BindableBool();
 
-        public IBindable<bool> IsActive => isActive;
+        /// <summary>
+        /// Whether <see cref="IsActive"/> should be <c>true</c>.
+        /// Takes effect on next call to <see cref="UpdateActiveState"/>.
+        /// </summary>
+        protected virtual bool ShouldBeActive => Focused;
+
+        protected void UpdateActiveState() => isActive.Value = ShouldBeActive;
 
         private readonly BindableBool cursorInWindow = new BindableBool();
 
@@ -505,11 +501,13 @@ private unsafe void handleWindowEvent(SDL_WindowEvent evtWindow)
                 case SDL_EventType.SDL_EVENT_WINDOW_RESTORED:
                 case SDL_EventType.SDL_EVENT_WINDOW_FOCUS_GAINED:
                     Focused = true;
+                    UpdateActiveState();
                     break;
 
                 case SDL_EventType.SDL_EVENT_WINDOW_MINIMIZED:
                 case SDL_EventType.SDL_EVENT_WINDOW_FOCUS_LOST:
                     Focused = false;
+                    UpdateActiveState();
                     break;
 
                 case SDL_EventType.SDL_EVENT_WINDOW_CLOSE_REQUESTED: