feat: Support CloseRequested and Suspending on macOS

src/Uno.Foundation/Deferral.cs

@@ -1,25 +1,28 @@
-using System;
-using System.Collections.Generic;
-using System.Runtime.InteropServices;
-using System.Text;
+using System.Runtime.InteropServices;
 
 namespace Windows.Foundation
 {
 	public delegate void DeferralCompletedHandler();
 
 	public sealed partial class Deferral : IClosable
 	{
-		private readonly DeferralCompletedHandler _handler;
-
-		/// <summary>Initializes a new Deferral object and specifies a DeferralCompletedHandler to be called upon completion of the deferral.</summary>
+		private readonly DeferralCompletedHandler _handler;
+
+		/// <summary>
+		/// Initializes a new Deferral object and specifies a DeferralCompletedHandler
+		/// to be called upon completion of the deferral.
+		/// </summary>
 		/// <param name="handler">A DeferralCompletedHandler to be called upon completion of the deferral.</param>
 		public Deferral([In] DeferralCompletedHandler handler)
 		{
 			_handler = handler;
 		}
 
-		/// <summary>If the DeferralCompletedHandler has not yet been invoked, this will call it and drop the reference to the delegate.</summary>
-		public void Complete() { _handler?.Invoke(); }
+		/// <summary>
+		/// If the DeferralCompletedHandler has not yet been invoked,
+		/// this will call it and drop the reference to the delegate.
+		/// </summary>
+		public void Complete() => _handler?.Invoke();
 
 		public void Close() { }
 	}

src/Uno.UI/Controls/Window.macOS.cs

@@ -19,6 +19,8 @@
 using Uno.Logging;
 using Windows.Foundation;
 using Windows.UI.ViewManagement;
+using Windows.UI.Core.Preview;
+using System.Threading.Tasks;
 
 namespace Uno.UI.Controls
 {
@@ -39,6 +41,7 @@ public partial class Window : NSWindow
 		public Window(CGRect contentRect, NSWindowStyle aStyle, NSBackingStore bufferingType, bool deferCreation)
 			: base(contentRect, aStyle, bufferingType, deferCreation)
 		{
+			Delegate = new WindowDelegate();
 			_inputPane = InputPane.GetForCurrentView();
 			_inputPane.Window = this;
 		}
@@ -114,5 +117,40 @@ internal void MakeVisible(NSView view, BringIntoViewMode? bringIntoViewMode, boo
 			scrollView.ScrollRectToVisible(viewRectInScrollView);
 		}
 
+		private class WindowDelegate : NSWindowDelegate
+		{
+			public override async void DidBecomeMain(NSNotification notification)
+			{
+				// Ensure custom cursor is reset after window activation.
+				// Artificial delay is necessary due to the fact that setting cursor
+				// immediately after window becoming main does not have any effect.
+				await Task.Delay(100);
+				CoreWindow.GetForCurrentThread().RefreshCursor();
+			}
+
+			public override bool WindowShouldClose(NSObject sender)
+			{
+				var manager = SystemNavigationManagerPreview.GetForCurrentView();
+				if (!manager.HasConfirmedClose)
+				{
+					var isHandled = manager.OnCloseRequested();
+					if (isHandled)
+					{
+						return false;
+					}
+				}
+
+				// closing should continue, perform suspension
+
+				if (!Application.Current.Suspended)
+				{
+					Application.Current.OnSuspending();
+					return Application.Current.Suspended;
+				}
+
+				// all prerequisites passed, can safely close
+				return true;
+			}
+		}
 	}
 }

src/Uno.UI/UI/Xaml/Application.cs

@@ -83,16 +83,16 @@ public ApplicationTheme RequestedTheme
 			}
 		}
 
-		public ResourceDictionary Resources { get; } = new ResourceDictionary();
-
-#pragma warning disable CS0067 // The event is never used
-		public event EventHandler<object> Resuming;
-#pragma warning restore CS0067 // The event is never used
-
-#pragma warning disable CS0067 // The event is never used
-		public event SuspendingEventHandler Suspending;
+		public ResourceDictionary Resources { get; } = new ResourceDictionary();
+
+#pragma warning disable CS0067 // The event is never used
+		public event EventHandler<object> Resuming;
+#pragma warning restore CS0067 // The event is never used
+
+#pragma warning disable CS0067 // The event is never used
+		public event SuspendingEventHandler Suspending;
 #pragma warning restore CS0067 // The event is never used
-
+
 		public event UnhandledExceptionEventHandler UnhandledException;
 
 		public void OnSystemThemeChanged()
@@ -157,8 +157,9 @@ internal void OnResuming()
 
 		internal void OnSuspending()
 		{
-			CoreApplication.RaiseSuspending(new SuspendingEventArgs(new SuspendingOperation(DateTime.Now.AddSeconds(30))));
-
+			var suspendingEventArgs = new SuspendingEventArgs(new SuspendingOperation(DateTime.Now.AddSeconds(30)));
+			CoreApplication.RaiseSuspending(suspendingEventArgs);
+
 			OnSuspendingPartial();
 		}
 

src/Uno.UI/UI/Xaml/Application.macOS.cs

@@ -40,6 +40,10 @@ public Application(IntPtr handle) : base(handle)
 
 		}
 
+		public override bool ApplicationShouldTerminateAfterLastWindowClosed(NSApplication sender) => true;
+
+		internal bool Suspended { get; private set; }
+
 		static partial void StartPartial(ApplicationInitializationCallback callback)
 		{
 			callback(new ApplicationInitializationCallbackParams());
@@ -73,6 +77,19 @@ public override void DidFinishLaunching(NSNotification notification)
 			}
 		}
 
+		partial void OnSuspendingPartial()
+		{
+			var operation = new SuspendingOperation(DateTime.Now.AddSeconds(0), () =>
+			{
+				Suspended = true;
+				NSApplication.SharedApplication.KeyWindow.PerformClose(null);
+			});
+
+			Suspending?.Invoke(this, new SuspendingEventArgs(operation));
+
+			operation.EventRaiseCompleted();
+		}
+
 		/// <summary>
 		/// This method enables UI Tests to get the output path
 		/// of the current application, in the context of the simulator.

src/Uno.UI/UI/Xaml/Controls/ContentDialog/ContentDialogClosingDeferral.cs

@@ -1,15 +1,21 @@
-using System;
+using Windows.Foundation;
 
 namespace Windows.UI.Xaml.Controls
 {
-	public partial class ContentDialogClosingDeferral : IDeferral
+	public partial class ContentDialogClosingDeferral
 	{
-		private Action _deferralAction;
+		private DeferralCompletedHandler _handler;
 
+		/// <summary>
+		/// This constructor does not exist in UWP
+		/// </summary>
 		public ContentDialogClosingDeferral() { }
 
-		Action IDeferral.DeferralAction { get => _deferralAction; set => _deferralAction = value; }
+		internal ContentDialogClosingDeferral(DeferralCompletedHandler handler)
+		{
+			_handler = handler;
+		}
 
-		public void Complete() => _deferralAction?.Invoke();
+		public void Complete() => _handler?.Invoke();
 	}
 }

src/Uno.UI/UI/Xaml/Controls/ContentDialog/ContentDialogClosingEventArgs.cs

@@ -1,4 +1,5 @@
 using System;
+using Uno.Helpers;
 
 namespace Windows.UI.Xaml.Controls
 {
@@ -13,6 +14,7 @@ internal ContentDialogClosingEventArgs(Action<ContentDialogClosingEventArgs> com
 
 			Result = result;
 		}
+
 		internal bool IsDeferred => _deferralManager != null;
 
 		public bool Cancel { get; set; }
@@ -21,7 +23,11 @@ internal ContentDialogClosingEventArgs(Action<ContentDialogClosingEventArgs> com
 
 		public ContentDialogClosingDeferral GetDeferral()
 		{
-			_deferralManager = _deferralManager ?? new DeferralManager<ContentDialogClosingDeferral>(() => _complete(this));
+			if (_deferralManager == null)
+			{
+				_deferralManager = new DeferralManager<ContentDialogClosingDeferral>(h => new ContentDialogClosingDeferral(h));
+				_deferralManager.Completed += (s, e) => _complete(this);
+			}
 
 			return _deferralManager.GetDeferral();
 		}

src/Uno.UWP/ApplicationModel/ISuspendingDeferral.cs

@@ -0,0 +1,7 @@
+namespace Windows.ApplicationModel
+{
+	public partial interface ISuspendingDeferral
+	{
+		void Complete();
+	}
+}

src/Uno.UWP/ApplicationModel/ISuspendingEventArgs.cs

@@ -0,0 +1,7 @@
+namespace Windows.ApplicationModel
+{
+	public partial interface ISuspendingEventArgs
+	{
+		SuspendingOperation SuspendingOperation { get; }
+	}
+}

src/Uno.UWP/ApplicationModel/ISuspendingOperation.cs

@@ -0,0 +1,11 @@
+using System;
+
+namespace Windows.ApplicationModel
+{
+	public partial interface ISuspendingOperation
+	{
+		DateTimeOffset Deadline { get; }
+
+		SuspendingDeferral GetDeferral();
+	}
+}

src/Uno.UWP/ApplicationModel/SuspendingDeferral.cs

@@ -1,19 +1,31 @@
 #nullable enable
 
 using System;
-using Uno;
+using System.Diagnostics;
 using Windows.Foundation;
-using Windows.Foundation.Metadata;
+
 namespace Windows.ApplicationModel
 {
 	public sealed partial class SuspendingDeferral
 	{
-		private Action? _deferralDone;
+		private readonly Action? _deferralDone;
+		private readonly DeferralCompletedHandler? _handler;
+
+		/// <summary>
+		/// This can be removed with other breaking changes
+		/// </summary>
+		/// <param name="deferralDone"></param>
+		[DebuggerHidden]
+		public SuspendingDeferral(Action? deferralDone)	=>
+			_deferralDone = deferralDone;
 
-		public SuspendingDeferral(Action? deferralDone)
-			=> _deferralDone = deferralDone;
+		internal SuspendingDeferral(DeferralCompletedHandler handler) =>
+			_handler = handler;
 
 		public void Complete()
-			=> _deferralDone?.Invoke();
+		{
+			_deferralDone?.Invoke();
+			_handler?.Invoke();
+		}
 	}
 }

src/Uno.UWP/ApplicationModel/SuspendingEventArgs.cs

@@ -1,9 +1,6 @@
-using System;
-using Windows.Foundation;
-using Windows.Foundation.Metadata;
 namespace Windows.ApplicationModel
 {
-	public sealed partial class SuspendingEventArgs
+	public sealed partial class SuspendingEventArgs : ISuspendingEventArgs
 	{
 		internal SuspendingEventArgs(SuspendingOperation operation)
 		{

src/Uno.UWP/ApplicationModel/SuspendingOperation.cs

@@ -1,12 +1,13 @@
 #nullable enable
 
 using System;
-using Windows.Foundation;
-using Windows.Foundation.Metadata;
+using Uno.Helpers;
+
 namespace Windows.ApplicationModel
 {
-	public sealed partial class SuspendingOperation
+	public sealed partial class SuspendingOperation : ISuspendingOperation
 	{
+		private DeferralManager<SuspendingDeferral>? _deferralManager;
 		private readonly Action? _deferralDone;
 
 		internal SuspendingOperation(DateTimeOffset offset, Action? deferralDone = null)
@@ -15,9 +16,20 @@ internal SuspendingOperation(DateTimeOffset offset, Action? deferralDone = null)
 			_deferralDone = deferralDone;
 		}
 
+		internal bool IsDeferred => _deferralManager != null;
+
+		internal void EventRaiseCompleted() => _deferralManager?.EventRaiseCompleted();
+
 		public DateTimeOffset Deadline { get; }
 
 		public SuspendingDeferral GetDeferral()
-			=> new SuspendingDeferral(_deferralDone);
+		{
+			if (_deferralManager == null)
+			{
+				_deferralManager = new DeferralManager<SuspendingDeferral>(h => new SuspendingDeferral(h));
+				_deferralManager.Completed += (s, e) => _deferralDone?.Invoke();
+			}
+			return _deferralManager.GetDeferral();
+		}		
 	}
 }

src/Uno.UWP/Generated/3.0.0.0/Windows.ApplicationModel/ISuspendingDeferral.cs

@@ -2,12 +2,12 @@
 #pragma warning disable 114 // new keyword hiding
 namespace Windows.ApplicationModel
 {
-	#if __ANDROID__ || __IOS__ || NET461 || __WASM__ || __MACOS__
+	#if false || false || false || false || false
 	[global::Uno.NotImplemented]
 	#endif
 	public  partial interface ISuspendingDeferral 
 	{
-		#if __ANDROID__ || __IOS__ || NET461 || __WASM__ || __MACOS__
+		#if false || false || false || false || false
 		void Complete();
 		#endif
 	}

src/Uno.UWP/Generated/3.0.0.0/Windows.ApplicationModel/ISuspendingOperation.cs

@@ -2,18 +2,18 @@
 #pragma warning disable 114 // new keyword hiding
 namespace Windows.ApplicationModel
 {
-	#if __ANDROID__ || __IOS__ || NET461 || __WASM__ || __MACOS__
+	#if false || false || false || false || false
 	[global::Uno.NotImplemented]
 	#endif
 	public  partial interface ISuspendingOperation 
 	{
-		#if __ANDROID__ || __IOS__ || NET461 || __WASM__ || __MACOS__
+		#if false || false || false || false || false
 		global::System.DateTimeOffset Deadline
 		{
 			get;
 		}
 		#endif
-		#if __ANDROID__ || __IOS__ || NET461 || __WASM__ || __MACOS__
+		#if false || false || false || false || false
 		global::Windows.ApplicationModel.SuspendingDeferral GetDeferral();
 		#endif
 		// Forced skipping of method Windows.ApplicationModel.ISuspendingOperation.Deadline.get