[Mac] Fix for preventing macOS picker dialog from closing immediately when opened with Tab

src/Controls/tests/TestCases.HostApp/Issues/Issue33463.cs

@@ -0,0 +1,30 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 33463, "[macOS]Picker items are not visible", PlatformAffected.macOS)]
+public class Issue33463 : TestContentPage
+{
+    protected override void Init()
+    {
+        var picker = new Picker
+        {
+            AutomationId = "TestPicker",
+            Title = "Select an item"
+        };
+        picker.Items.Add("Item 1");
+        picker.Items.Add("Item 2");
+        picker.Items.Add("Item 3");
+
+        var entry = new Entry
+        {
+            AutomationId = "TestEntry",
+            Placeholder = "Entry for TAB focus"
+        };
+
+        Content = new VerticalStackLayout
+        {
+            Padding = 12,
+            Spacing = 10,
+            Children = { picker, entry }
+        };
+    }
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue33463.cs

@@ -0,0 +1,34 @@
+#if MACCATALYST // The reported scenario is specific to macOS, where the picker dialog closes automatically when opened using the Tab key, so this test is enabled only for macOS.
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue33463 : _IssuesUITest
+{
+	public Issue33463(TestDevice testDevice) : base(testDevice)
+	{
+	}
+
+	public override string Issue => "[macOS]Picker items are not visible";
+
+	[Test]
+	[Category(UITestCategories.Picker)]
+	public void PickerShouldRemainOpenWhenOpenedUsingTabKey()
+	{
+		App.WaitForElement("TestPicker");
+
+		App.Tap("TestPicker");
+		App.WaitForElement("Done");
+		App.Tap("Done");
+
+		App.SendTabKey();
+		Task.Delay(800).Wait();
+
+		var doneButton = App.FindElement("Done");
+		Assert.That(doneButton, Is.Not.Null, 
+			"The picker dialog should remain open when it is opened using the Tab key.");
+	}
+}
+#endif

src/Core/src/Handlers/Picker/PickerHandler.cs

@@ -33,7 +33,7 @@ public partial class PickerHandler : IPickerHandler
 
 		public static CommandMapper<IPicker, IPickerHandler> CommandMapper = new(ViewCommandMapper)
 		{
-#if ANDROID
+#if ANDROID || MACCATALYST
 			[nameof(IPicker.Focus)] = MapFocus,
 			[nameof(IPicker.Unfocus)] = MapUnfocus
 #endif

src/Core/src/Handlers/Picker/PickerHandler.iOS.cs

@@ -9,6 +9,9 @@ public partial class PickerHandler : ViewHandler<IPicker, MauiPicker>
 	{
 		readonly MauiPickerProxy _proxy = new();
 		UIPickerView? _pickerView;
+#if MACCATALYST
+		UIAlertController? _currentPickerController;
+#endif
 
 #if !MACCATALYST
 		protected override MauiPicker CreatePlatformView()
@@ -59,7 +62,8 @@ void DisplayAlert(MauiPicker uITextField, int selectedIndex)
 
 			// The UIPickerView is displayed as a subview of the UIAlertController when an empty string is provided as the title, instead of using the VirtualView title. 
 			// This behavior deviates from the expected native macOS behavior.
-			var pickerController = UIAlertController.Create("", "", UIAlertControllerStyle.ActionSheet);
+			_currentPickerController = UIAlertController.Create("", "", UIAlertControllerStyle.ActionSheet);
+			var pickerController = _currentPickerController;
 
 			// needs translation
 			pickerController.AddAction(UIAlertAction.Create("Done",
@@ -84,11 +88,13 @@ void DisplayAlert(MauiPicker uITextField, int selectedIndex)
 
 			EventHandler? editingDidEndHandler = null;
 
-			editingDidEndHandler = async (s, e) =>
+			editingDidEndHandler = (s, e) =>
 			{
-				await pickerController.DismissViewControllerAsync(true);
 				if (VirtualView is IPicker virtualView)
 					virtualView.IsFocused = virtualView.IsOpen = false;
+
+				_currentPickerController = null;
+
 				uITextField.EditingDidEnd -= editingDidEndHandler;
 			};
 
@@ -202,6 +208,32 @@ internal static void MapIsOpen(IPickerHandler handler, IPicker picker)
 			handler.PlatformView?.UpdateIsOpen(picker);
 		}
 
+#if MACCATALYST
+		internal static void MapFocus(IPickerHandler handler, IPicker picker, object? args)
+		{
+			if (handler.IsConnected() && handler is PickerHandler)
+			{
+				ViewHandler.MapFocus(handler, picker, args);
+			}
+		}
+
+		internal static void MapUnfocus(IPickerHandler handler, IPicker picker, object? args)
+		{
+			if (handler.IsConnected() && handler is PickerHandler pickerHandler)
+			{
+				// Dismiss the picker controller when Unfocus() is explicitly called
+				if (pickerHandler._currentPickerController != null)
+				{
+					var controller = pickerHandler._currentPickerController;
+					pickerHandler._currentPickerController = null;
+					controller.DismissViewController(true, null);
+				}
+
+				ViewHandler.MapUnfocus(handler, picker, args);
+			}
+		}
+#endif
+
 		void UpdatePickerFromPickerSource(PickerSource? pickerSource)
 		{
 			if (VirtualView == null || PlatformView == null || pickerSource == null)