[MacCatalyst] Fix DatePicker Opened/Closed events not being raised

src/Controls/tests/TestCases.HostApp/Issues/Issue34848.cs

@@ -0,0 +1,46 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 34848, "DatePicker Opened and Closed events are not raised on MacCatalyst", PlatformAffected.macOS)]
+public class Issue34848 : TestContentPage
+{
+	DatePicker _datePicker;
+	Label _openStatusLabel;
+	Label _closeStatusLabel;
+	protected override void Init()
+	{
+		_openStatusLabel = new Label
+		{
+			AutomationId = "Issue34848OpenStatusLabel",
+			Text = "Opened: Unknown",
+			HorizontalOptions = LayoutOptions.Center
+		};
+
+		_closeStatusLabel = new Label
+		{
+			AutomationId = "Issue34848CloseStatusLabel",
+			Text = "Closed: Unknown",
+			HorizontalOptions = LayoutOptions.Center
+		};
+
+		_datePicker = new DatePicker
+		{
+			AutomationId = "Issue34848TestDatePicker",
+			Date = DateTime.Today,
+			HorizontalOptions = LayoutOptions.Center
+		};
+
+		_datePicker.Opened += (s, e) => _openStatusLabel.Text = "Opened";
+		_datePicker.Closed += (s, e) => _closeStatusLabel.Text = "Closed";
+
+		Content = new VerticalStackLayout
+		{
+			Spacing = 10,
+			Children =
+			{
+				_openStatusLabel,
+				_closeStatusLabel,
+				_datePicker
+			}
+		};
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue34848.cs

@@ -0,0 +1,41 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue34848 : _IssuesUITest
+{
+	public Issue34848(TestDevice testDevice) : base(testDevice) { }
+
+	public override string Issue => "DatePicker Opened and Closed events are not raised on MacCatalyst";
+
+	[Test]
+	[Category(UITestCategories.DatePicker)]
+	public void DatePickerOpenedAndClosedEventsAreRaised()
+	{
+		App.WaitForElement("Issue34848OpenStatusLabel");
+		App.WaitForElement("Issue34848CloseStatusLabel");
+		App.WaitForElement("Issue34848TestDatePicker");
+
+		// Open the DatePicker
+		App.Tap("Issue34848TestDatePicker");
+
+#if IOS
+		// iOS DatePicker uses a wheel picker, so we can just tap the "Done" button to close it
+		App.Tap("Done");
+#elif WINDOWS
+		// On Windows, we can tap a date to close the DatePicker
+		App.Tap("16");
+#elif ANDROID
+		// On Android, we can tap the "Cancel" button to close the DatePicker
+		App.Tap("Cancel");
+#else
+		// On MacCatalyst, we can tap outside the DatePicker to close it
+		App.TapCoordinates(30, 30);
+#endif
+
+		Assert.That(App.WaitForElement("Issue34848OpenStatusLabel").GetText(), Is.EqualTo("Opened"));
+		Assert.That(App.WaitForElement("Issue34848CloseStatusLabel").GetText(), Is.EqualTo("Closed"));
+	}
+}

src/Core/src/Handlers/DatePicker/DatePickerHandler.MacCatalyst.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using Foundation;
 using UIKit;
 using RectangleF = CoreGraphics.CGRect;
@@ -7,7 +8,11 @@ namespace Microsoft.Maui.Handlers
 {
 	public partial class DatePickerHandler : ViewHandler<IDatePicker, UIDatePicker>
 	{
+		static readonly NSString WindowDidCloseNotification = new("NSWindowDidCloseNotification");
+
 		readonly UIDatePickerProxy _proxy = new();
+		NSObject? _windowCloseObserver;
+		bool _isDatePickerOpen;
 
 		protected override UIDatePicker CreatePlatformView()
 		{
@@ -26,16 +31,129 @@ protected override void ConnectHandler(UIDatePicker platformView)
 				platformView.Date = dt.ToNSDate();
 			}
 
+			// The compact UIDatePicker on MacCatalyst uses internal UITextField subviews
+			// for the date segments. Wire up EditingDidBegin directly on those fields.
+			WireTextFields(platformView);
+
 			base.ConnectHandler(platformView);
 		}
 
 		protected override void DisconnectHandler(UIDatePicker platformView)
 		{
 			_proxy.Disconnect(platformView);
 
+			UnwireTextFields(platformView);
+
+			if (_windowCloseObserver is not null)
+			{
+				NSNotificationCenter.DefaultCenter.RemoveObserver(_windowCloseObserver);
+				_windowCloseObserver = null;
+			}
+
+			_isDatePickerOpen = false;
+
 			base.DisconnectHandler(platformView);
 		}
 
+
+		// Recursively traverses the view hierarchy and yields all UITextField subviews.
+		// Used to find the internal text fields of the compact UIDatePicker on MacCatalyst.
+		static IEnumerable<UITextField> GetTextFields(UIView view)
+		{
+			foreach (var subview in view.Subviews)
+			{
+
+				if (subview is UITextField textField)
+				{
+					yield return textField;
+				}
+				else
+				{
+					foreach (var nested in GetTextFields(subview))
+					{
+						yield return nested;
+					}
+				}
+			}
+		}
+
+		void WireTextFields(UIView view)
+		{
+			foreach (var textField in GetTextFields(view))
+			{
+				textField.EditingDidBegin += OnEditingDidBegin;
+			}
+		}
+
+		void UnwireTextFields(UIView view)
+		{
+			foreach (var textField in GetTextFields(view))
+			{
+				textField.EditingDidBegin -= OnEditingDidBegin;
+			}
+		}
+
+		void OnEditingDidBegin(object? sender, EventArgs e)
+		{
+			if (_isDatePickerOpen)
+			{
+				return;
+			}
+
+			_isDatePickerOpen = true;
+
+			// Register a one-shot observer scoped to this picker's open lifetime.
+			// On MacCatalyst the popover runs in an AppKit NSWindow; tapping outside
+			// dismisses it at the AppKit level without firing UITextField EditingDidEnd.
+			// Registering here (not in ConnectHandler) avoids spurious fires from
+			// unrelated window closes while the picker is not open.
+			_windowCloseObserver = NSNotificationCenter.DefaultCenter.AddObserver(WindowDidCloseNotification, OnWindowClosed);
+
+			if (VirtualView is IDatePicker virtualView)
+			{
+				virtualView.IsFocused = virtualView.IsOpen = true;
+			}
+		}
+
+		void OnWindowClosed(NSNotification notification)
+		{
+			// One-shot: remove the observer immediately so it won't fire again.
+			if (_windowCloseObserver is not null)
+			{
+				NSNotificationCenter.DefaultCenter.RemoveObserver(_windowCloseObserver);
+				_windowCloseObserver = null;
+			}
+
+			_isDatePickerOpen = false;
+
+			if (VirtualView is IDatePicker virtualView)
+			{
+				virtualView.IsFocused = virtualView.IsOpen = false;
+			}
+
+			// On MacCatalyst the internal UITextFields stay as first responder
+			// (visually highlighted) even after the popover window closes.
+			// EndEditing(true) on the parent view does not propagate to them,
+			// so we must directly resign each tracked text field on the next
+			// run-loop iteration (the notification fires before UIKit is ready).
+			ResignTextFields();
+		}
+
+		void ResignTextFields()
+		{
+			var platformView = PlatformView;
+			CoreFoundation.DispatchQueue.MainQueue.DispatchAsync(() =>
+			{
+				foreach (var textField in GetTextFields(platformView))
+				{
+					if (textField.IsFirstResponder)
+					{
+						textField.ResignFirstResponder();
+					}
+				}
+			});
+		}
+
 		public static partial void MapFormat(IDatePickerHandler handler, IDatePicker datePicker)
 		{
 			handler.PlatformView?.UpdateFormat(datePicker);
@@ -102,15 +220,11 @@ public void Connect(DatePickerHandler handler, IDatePicker virtualView, UIDatePi
 				_handler = new(handler);
 				_virtualView = new(virtualView);
 
-				platformView.EditingDidBegin += OnStarted;
-				platformView.EditingDidEnd += OnEnded;
 				platformView.ValueChanged += OnValueChanged;
 			}
 
 			public void Disconnect(UIDatePicker platformView)
 			{
-				platformView.EditingDidBegin -= OnStarted;
-				platformView.EditingDidEnd -= OnEnded;
 				platformView.ValueChanged -= OnValueChanged;
 			}
 
@@ -122,18 +236,6 @@ void OnValueChanged(object? sender, EventArgs? e)
 				if (VirtualView is IDatePicker virtualView)
 					virtualView.IsFocused = true;
 			}
-
-			void OnStarted(object? sender, EventArgs eventArgs)
-			{
-				if (VirtualView is IDatePicker virtualView)
-					virtualView.IsFocused = true;
-			}
-
-			void OnEnded(object? sender, EventArgs eventArgs)
-			{
-				if (VirtualView is IDatePicker virtualView)
-					virtualView.IsFocused = false;
-			}
 		}
 	}
-}
+}