[Mac Catalyst] Set window dimensions

src/Core/src/Handlers/Window/WindowHandler.iOS.cs

@@ -1,17 +1,38 @@
 using System;
-using ObjCRuntime;
+using Foundation;
 using UIKit;
 
 namespace Microsoft.Maui.Handlers
 {
 	public partial class WindowHandler : ElementHandler<IWindow, UIWindow>
 	{
+		readonly WindowProxy _proxy = new();
+
 		protected override void ConnectHandler(UIWindow platformView)
 		{
 			base.ConnectHandler(platformView);
 
-			UpdateVirtualViewFrame(platformView);
+			// For newer Mac Catalyst versions, we want to wait until we get effective window dimensions from the platform.
+			if (OperatingSystem.IsMacCatalystVersionAtLeast(16))
+			{
+				_proxy.Connect(VirtualView, platformView);
+			} 
+			else 
+			{
+				UpdateVirtualViewFrame(platformView);
+			}
+		}
+
+		protected override void DisconnectHandler(UIWindow platformView)
+		{
+			if (OperatingSystem.IsMacCatalystVersionAtLeast(16)) 
+			{
+				_proxy.Disconnect();
+			}
+
+			base.DisconnectHandler(platformView);
 		}
+
 		public static void MapTitle(IWindowHandler handler, IWindow window) =>
 			handler.PlatformView.UpdateTitle(window);
 
@@ -23,8 +44,7 @@ public static void MapContent(IWindowHandler handler, IWindow window)
 
 			handler.PlatformView.RootViewController = nativeContent;
 
-			if (window.VisualDiagnosticsOverlay != null)
-				window.VisualDiagnosticsOverlay.Initialize();
+			window.VisualDiagnosticsOverlay?.Initialize();
 		}
 
 		public static void MapX(IWindowHandler handler, IWindow view) =>
@@ -82,12 +102,53 @@ public static void MapMenuBar(IWindowHandler handler, IWindow view)
 		public static void MapRequestDisplayDensity(IWindowHandler handler, IWindow window, object? args)
 		{
 			if (args is DisplayDensityRequest request)
+			{
 				request.SetResult(handler.PlatformView.GetDisplayDensity());
+			}
 		}
 
 		void UpdateVirtualViewFrame(UIWindow window)
 		{
 			VirtualView.FrameChanged(window.Bounds.ToRectangle());
 		}
+
+		class WindowProxy
+		{
+			WeakReference<IWindow>? _virtualView;
+
+			IWindow? VirtualView => _virtualView is not null && _virtualView.TryGetTarget(out var v) ? v : null;
+			IDisposable? _effectiveGeometryObserver;
+
+			public void Connect(IWindow virtualView, UIWindow platformView)
+			{
+				_virtualView = new(virtualView);
+
+				// https://developer.apple.com/documentation/uikit/uiwindowscene/effectivegeometry?language=objc#Discussion mentions:
+				// > This property is key-value observing (KVO) compliant. Observing effectiveGeometry is the recommended way
+				// > to receive notifications of changes to the window scene’s geometry. These changes can occur because of
+				// > user interaction or as a result of the system resolving a geometry request.
+				_effectiveGeometryObserver = platformView.WindowScene?.AddObserver("effectiveGeometry", NSKeyValueObservingOptions.OldNew, HandleEffectiveGeometryObserved);
+			}
+
+			public void Disconnect()
+			{
+				_effectiveGeometryObserver?.Dispose();
+			}
+
+			void HandleEffectiveGeometryObserved(NSObservedChange obj)
+			{
+				if (obj is not null && VirtualView is IWindow virtualView && obj.NewValue is UIWindowSceneGeometry newGeometry)
+				{
+					var newRectangle = newGeometry.SystemFrame.ToRectangle();
+
+					if (double.IsNaN(newRectangle.X) || double.IsNaN(newRectangle.Y) || double.IsNaN(newRectangle.Width) || double.IsNaN(newRectangle.Height)) 
+					{
+						return;
+					}
+
+					virtualView.FrameChanged(newRectangle);
+				}
+			}
+		}
 	}
 }

src/Core/src/Hosting/LifecycleEvents/AppHostBuilderExtensions.iOS.cs

@@ -105,21 +105,30 @@ static void OnConfigureWindow(IiOSLifecycleBuilder iOS)
 		{
 			// Pre iOS 13 doesn't support scenes
 			if (!OperatingSystem.IsIOSVersionAtLeast(13))
+			{
 				return;
+			}
 
 			iOS = iOS
 				.WindowSceneDidUpdateCoordinateSpace((windowScene, _, _, _) =>
 				{
-					if (!OperatingSystem.IsIOSVersionAtLeast(13))
+					// Mac Catalyst version 16+ supports effectiveGeometry property on window scenes.
+					if (!OperatingSystem.IsIOSVersionAtLeast(13) || (OperatingSystem.IsMacCatalystVersionAtLeast(16)))
+					{
 						return;
+					}
 
 					if (windowScene.Delegate is not IUIWindowSceneDelegate wsd ||
 						wsd.GetWindow() is not UIWindow platformWindow)
+					{
 						return;
+					}
 
 					var window = platformWindow.GetWindow();
 					if (window is null)
+					{
 						return;
+					}
 
 					window.FrameChanged(platformWindow.Frame.ToRectangle());
 				});

src/Core/src/Platform/iOS/WindowExtensions.cs

@@ -2,6 +2,8 @@
 using System.Collections.Generic;
 using System.Text;
 using System.Threading.Tasks;
+using CoreGraphics;
+using Microsoft.Extensions.Logging;
 using Microsoft.Maui.Devices;
 using UIKit;
 
@@ -15,23 +17,46 @@ internal static void UpdateTitle(this UIWindow platformWindow, IWindow window)
 			// If you set it to an empty string the title reverts back to the 
 			// default app title.
 			if (OperatingSystem.IsIOSVersionAtLeast(13) && platformWindow.WindowScene is not null)
+			{
 				platformWindow.WindowScene.Title = window.Title ?? String.Empty;
+			}
 		}
 
 		internal static void UpdateX(this UIWindow platformWindow, IWindow window) =>
-			platformWindow.UpdateUnsupportedCoordinate(window);
+			platformWindow.UpdateCoordinates(window);
 
 		internal static void UpdateY(this UIWindow platformWindow, IWindow window) =>
-			platformWindow.UpdateUnsupportedCoordinate(window);
+			platformWindow.UpdateCoordinates(window);
 
 		internal static void UpdateWidth(this UIWindow platformWindow, IWindow window) =>
-			platformWindow.UpdateUnsupportedCoordinate(window);
+			platformWindow.UpdateCoordinates(window);
 
 		internal static void UpdateHeight(this UIWindow platformWindow, IWindow window) =>
-			platformWindow.UpdateUnsupportedCoordinate(window);
+			platformWindow.UpdateCoordinates(window);
 
-		internal static void UpdateUnsupportedCoordinate(this UIWindow platformWindow, IWindow window) =>
-			window.FrameChanged(platformWindow.Bounds.ToRectangle());
+		internal static void UpdateCoordinates(this UIWindow platformWindow, IWindow window)
+		{
+			if (OperatingSystem.IsMacCatalyst() && OperatingSystem.IsIOSVersionAtLeast(16) && platformWindow.WindowScene is {} windowScene)
+			{
+				if (double.IsNaN(window.X) || double.IsNaN(window.Y) || double.IsNaN(window.Width) || double.IsNaN(window.Height)) 
+				{
+					return;
+				}
+
+				var preferences = new UIWindowSceneGeometryPreferencesMac()
+				{
+					SystemFrame = new CGRect(window.X, window.Y, window.Width, window.Height)
+				};
+
+				windowScene.RequestGeometryUpdate(preferences, (error) => {
+					window.Handler?.MauiContext?.CreateLogger<UIWindow>()?.LogError("Requesting geometry update failed with error '{error}'.", error);
+				});
+			}
+			else
+			{
+				window.FrameChanged(platformWindow.Bounds.ToRectangle());
+			}
+		}
 
 		public static void UpdateMaximumWidth(this UIWindow platformWindow, IWindow window) =>
 			platformWindow.UpdateMaximumSize(window.MaximumWidth, window.MaximumHeight);
@@ -45,7 +70,9 @@ public static void UpdateMaximumSize(this UIWindow platformWindow, IWindow windo
 		internal static void UpdateMaximumSize(this UIWindow platformWindow, double width, double height)
 		{
 			if (!OperatingSystem.IsIOSVersionAtLeast(13))
+			{
 				return;
+			}
 
 			var restrictions = platformWindow.WindowScene?.SizeRestrictions;
 			if (restrictions is null)
@@ -71,7 +98,9 @@ public static void UpdateMinimumSize(this UIWindow platformWindow, IWindow windo
 		internal static void UpdateMinimumSize(this UIWindow platformWindow, double width, double height)
 		{
 			if (!OperatingSystem.IsIOSVersionAtLeast(13))
+			{
 				return;
+			}
 
 			var restrictions = platformWindow.WindowScene?.SizeRestrictions;
 			if (restrictions is null)

src/Core/src/PublicAPI/net-ios/PublicAPI.Unshipped.txt

@@ -80,3 +80,4 @@ override Microsoft.Maui.Platform.MauiCALayer.Dispose(bool disposing) -> void
 override Microsoft.Maui.Platform.MauiCALayer.RemoveFromSuperLayer() -> void
 override Microsoft.Maui.Handlers.BorderHandler.PlatformArrange(Microsoft.Maui.Graphics.Rect rect) -> void
 override Microsoft.Maui.Handlers.EditorHandler.NeedsContainer.get -> bool
+override Microsoft.Maui.Handlers.WindowHandler.DisconnectHandler(UIKit.UIWindow! platformView) -> void

src/Core/src/PublicAPI/net-maccatalyst/PublicAPI.Unshipped.txt

@@ -80,3 +80,4 @@ override Microsoft.Maui.Platform.MauiCALayer.Dispose(bool disposing) -> void
 override Microsoft.Maui.Platform.MauiCALayer.RemoveFromSuperLayer() -> void
 override Microsoft.Maui.Handlers.BorderHandler.PlatformArrange(Microsoft.Maui.Graphics.Rect rect) -> void
 override Microsoft.Maui.Handlers.EditorHandler.NeedsContainer.get -> bool
+override Microsoft.Maui.Handlers.WindowHandler.DisconnectHandler(UIKit.UIWindow! platformView) -> void