[iOS, Mac] Fix for CursorPosition not updating when typing into Entry control

src/Controls/tests/TestCases.HostApp/Issues/Issue20911.cs

@@ -0,0 +1,41 @@
+namespace Controls.TestCases.HostApp.Issues;
+
+[Issue(IssueTracker.Github, 20911, "Updating text in the Entry does not update CursorPosition during the TextChanged event", PlatformAffected.iOS)]
+public class Issue20911 : ContentPage
+{
+	Entry entry;
+	Label cursorPositonStatusLabel;
+
+	public Issue20911()
+	{
+		entry = new Entry
+		{
+			AutomationId = "ValidateEntryCursorPosition",
+		};
+
+		cursorPositonStatusLabel = new Label
+		{
+			AutomationId = "CursorPositionStatusLabel",
+			Text = "Cursor Position: 0",
+			FontSize = 16,
+		};
+
+		Button button = new Button
+		{
+			AutomationId = "ValidateEntryCursorPositionBtn",
+			Text = "Validate Entry Cursor Position",
+		};
+
+		button.Clicked += (sender, e) =>
+		{
+			cursorPositonStatusLabel.Text = $"{entry.CursorPosition}";
+		};
+
+		Content = new VerticalStackLayout
+		{
+			Padding = new Thickness(20),
+			Spacing = 10,
+			Children = { entry, cursorPositonStatusLabel, button }
+		};
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue20911.cs

@@ -0,0 +1,29 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue20911 : _IssuesUITest
+{
+	public Issue20911(TestDevice device) : base(device)
+	{
+	}
+
+	public override string Issue => "Updating text in the Entry does not update CursorPosition during the TextChanged event";
+
+	[Test]
+	[Category(UITestCategories.Entry)]
+	public void VerifyEntryCursorPositionOnTextChanged()
+	{
+		App.WaitForElement("ValidateEntryCursorPosition");
+
+		App.EnterText("ValidateEntryCursorPosition", "Test");
+
+		App.WaitForElement("ValidateEntryCursorPositionBtn");
+		App.Tap("ValidateEntryCursorPositionBtn");
+
+		var cursorPositionStatus = App.FindElement("CursorPositionStatusLabel").GetText();
+		Assert.That(cursorPositionStatus, Is.EqualTo("4"));
+	}
+}

src/Core/src/Core/Extensions/ITextInputExtensions.cs

@@ -50,6 +50,14 @@ public static bool TextWithinMaxLength(this ITextInput textInput, string? text,
 
 			return shouldChange;
 		}
+
+		internal static void UpdateCursorPosition(this ITextInput textInput, int cursorPosition)
+		{
+			if (textInput.CursorPosition != cursorPosition)
+			{
+				textInput.CursorPosition = cursorPosition;
+			}
+		}
 #endif
 
 #if ANDROID

src/Core/src/Handlers/Entry/EntryHandler.iOS.cs

@@ -190,12 +190,16 @@ void OnEditingBegan(object? sender, EventArgs e)
 
 			void OnEditingChanged(object? sender, EventArgs e)
 			{
-				if (sender is MauiTextField platformView)
+				if (sender is MauiTextField platformView && VirtualView is not null)
 				{
-					VirtualView?.UpdateText(platformView.Text);
-				}
-			}
+					// Update cursor position before updating text so that when TextChanged event fires,
+					// the CursorPosition property reflects the current native cursor position
+					VirtualView.UpdateCursorPosition(platformView.GetCursorPosition());
 
+					VirtualView.UpdateText(platformView.Text);
+				}
+			}	
+
 			void OnEditingEnded(object? sender, EventArgs e)
 			{
 				if (sender is MauiTextField platformView && VirtualView is IEntry virtualView)