fix: Updated workaround for iOS 16 UITextInput.SelectedTextRange cr…

…ashes

Pro: It does not break app compatibility, selection works

Con: This does not work _currently_ with the dynamic registrar [1] which is the default when building for iOS simulators. OTOH there's a workaround for that [2].

[1] Unless building with the iOS SDK for Xcode 14 (currently only previews) once xamarin/xamarin-macios#15712 is merged

[2] Adding `--registrar=static` to the simulator builds will fix this, sadly build times will be longer (so better use [1] asap)

src/Uno.UI/FeatureConfiguration.cs

@@ -375,15 +375,6 @@ public static class TextBox
 			/// </summary>
 			/// <remarks>This feature is used to avoid screenshot comparisons false positives</remarks>
 			public static bool HideCaret { get; set; } = false;
-
-#if __IOS__
-			/// <summary>
-			/// As of iOS 16 Beta 4, the selection events are crashing the application. This feature configuration is added
-			/// to provide the ability to restore the original behavior if/when the underlying UIKit is fixed.
-			/// See https://github.com/unoplatform/uno/issues/9430 for additional details.
-			/// </summary>
-			public static bool IOS16EnableSelectionSupport { get; set; }
-#endif
 		}
 
 		public static class ScrollViewer

src/Uno.UI/UI/Xaml/Controls/TextBox/SinglelineTextBoxView.iOS.cs

@@ -1,8 +1,10 @@
 using CoreGraphics;
+using ObjCRuntime;
 using Uno.UI.DataBinding;
 using Uno.UI.Views.Controls;
 using System;
 using System.Collections.Generic;
+using System.Runtime.InteropServices;
 using System.Text;
 using UIKit;
 using Uno.Extensions;
@@ -23,8 +25,6 @@ public partial class SinglelineTextBoxView : UITextField, ITextBoxView, Dependen
 		private readonly WeakReference<TextBox> _textBox;
 		private readonly SerialDisposable _foregroundChanged = new SerialDisposable();
 
-		private static bool _issue9430WarnSingle = false;
-
 		public SinglelineTextBoxView(TextBox textBox)
 		{
 			_textBox = new WeakReference<TextBox>(textBox);
@@ -33,24 +33,6 @@ public SinglelineTextBoxView(TextBox textBox)
 			Initialize();
 		}
 
-		internal static SinglelineTextBoxView CreateSinglelineTextBoxView(TextBox textBox)
-		{
-			if (UIDevice.CurrentDevice.CheckSystemVersion(16, 0) && !FeatureConfiguration.TextBox.IOS16EnableSelectionSupport)
-			{
-				if (!_issue9430WarnSingle && typeof(SinglelineTextBoxView).Log().IsEnabled(LogLevel.Error))
-				{
-					_issue9430WarnSingle = true;
-					typeof(SinglelineTextBoxView).Log().Error($"TextBox selection events are disabled on iOS 16. See https://github.com/unoplatform/uno/issues/9430 for additional details.");
-				}
-
-				return new SinglelineTextBoxView(textBox);
-			}
-			else
-			{
-				return new SinglelineTextBoxViewWithSelection(textBox);
-			}
-		}
-
 		internal TextBox TextBox => _textBox.GetTarget();
 
 		private void OnEditingChanged(object sender, EventArgs e)
@@ -224,31 +206,30 @@ public void RefreshFont()
 		{
 			UpdateFont();
 		}
-	}
 
-	/// <summary>
-	/// Workaround for https://github.com/unoplatform/uno/issues/9430
-	/// </summary>
-	internal partial class SinglelineTextBoxViewWithSelection : SinglelineTextBoxView
-	{
-		public SinglelineTextBoxViewWithSelection(TextBox textBox)
-			: base(textBox)
-		{
-		}
+		/// <summary>
+		/// Workaround for https://github.com/unoplatform/uno/issues/9430
+		/// </summary>
+		[DllImport(Constants.ObjectiveCLibrary, EntryPoint = "objc_msgSendSuper")]
+		static extern IntPtr IntPtr_objc_msgSendSuper(IntPtr receiver, IntPtr selector);
+
+		[DllImport(Constants.ObjectiveCLibrary, EntryPoint = "objc_msgSendSuper")]
+		static extern void void_objc_msgSendSuper(IntPtr receiver, IntPtr selector, IntPtr arg);
 
-		public override UITextRange SelectedTextRange
+		[Export("selectedTextRange")]
+		public new IntPtr SelectedTextRange
 		{
 			get
 			{
-				return base.SelectedTextRange;
+				return IntPtr_objc_msgSendSuper(SuperHandle, Selector.GetHandle("selectedTextRange"));
 			}
 			set
 			{
 				var textBox = TextBox;
 
-				if (textBox != null && base.SelectedTextRange != value)
+				if (textBox != null && IntPtr_objc_msgSendSuper(SuperHandle, Selector.GetHandle("selectedTextRange")) != value)
 				{
-					base.SelectedTextRange = value;
+					void_objc_msgSendSuper(SuperHandle, Selector.GetHandle("setSelectedTextRange:"), value);
 					textBox.OnSelectionChanged();
 				}
 			}

src/Uno.UI/UI/Xaml/Controls/TextBox/TextBox.iOS.cs

@@ -103,7 +103,7 @@ private void UpdateTextBoxView()
 						return;
 					}
 
-					_textBoxView = SinglelineTextBoxView.CreateSinglelineTextBoxView(this);
+					_textBoxView = new SinglelineTextBoxView(this);
 
 					_contentElement.Content = _textBoxView;
 					_textBoxView.SetTextNative(Text);