[Windows] Respect `ClearButtonVisibility = ClearButtonVisibility.Neve…

…r` for `<Entry>`s (dotnet#23158)

### Description of Change

The style interception code works sometimes but not always. 

Relevant XAML template in WinUI 3 is
[here](https://github.com/microsoft/microsoft-ui-xaml/blob/98a60c8f30c84f297a175dd2884d54ecd1c8a4a9/controls/dev/CommonStyles/TextBox_themeresources.xaml#L311-L341).

### Issues Fixed

Fixes dotnet#23112
Related to dotnet#13714

PR that introduced the modified code: dotnet#3444

src/Controls/tests/TestCases.HostApp/Issues/Issue23158.xaml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             xmlns:local="clr-namespace:Maui.Controls.Sample.Issues"
+             x:Class="Maui.Controls.Sample.Issues.Issue23158"
+             x:DataType="local:Issue23158">
+
+  <VerticalStackLayout Padding="30,0">
+    <Button AutomationId="AddEntry" Text="Add entry dynamically" Margin="0,0,0,30" Clicked="AddEntryButton_Clicked"/>
+
+    <!-- First entry. -->
+    <Label Text="Entry.ClearButtonVisibility=Never"/>
+    <Entry x:Name="Entry1" ClearButtonVisibility="Never" Text="A"/>
+
+    <!-- Second entry. -->
+    <Label Text="Entry.ClearButtonVisibility=WhileEditing"/>
+    <Entry x:Name="Entry2" ClearButtonVisibility="WhileEditing" Text="B"/>
+
+    <!-- Third entry. See #23112. -->
+    <Label Text="Dynamically Entry.ClearButtonVisibility=Never + Focus"/>
+    <VerticalStackLayout x:Name="Entry3Container"/> <!-- Container for a dynamically added entry. -->
+
+    <Label AutomationId="TestInstructions" Margin="0,30,0,0" FontAttributes="Bold"
+           Text="Instructions: Click the top-most button and the third entry should not contain any clear button!"/>
+  </VerticalStackLayout>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue23158.xaml.cs

@@ -0,0 +1,26 @@
+namespace Maui.Controls.Sample.Issues;
+
+[XamlCompilation(XamlCompilationOptions.Compile)]
+[Issue(IssueTracker.Github, 23158, "Respect Entry.ClearButtonVisibility on Windows", PlatformAffected.UWP)]
+public partial class Issue23158 : ContentPage
+{
+	public Issue23158()
+	{
+		InitializeComponent();
+	}
+
+	private void AddEntryButton_Clicked(object sender, EventArgs e)
+	{
+		Entry entry = new Entry() 
+		{ 
+			Text = "Some Text",
+			AutomationId = "Entry3"
+		};
+
+		Entry3Container.Children.Add(entry);
+
+		// Intentionally, after the entry is added to its layout container.
+		entry.ClearButtonVisibility = ClearButtonVisibility.Never;
+		entry.Focus();
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue23158.cs

@@ -0,0 +1,31 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue23158 : _IssuesUITest
+{
+	public override string Issue => "Respect Entry.ClearButtonVisibility on Windows";
+
+	public Issue23158(TestDevice device) : base(device)
+	{
+	}
+
+#if !MACCATALYST
+	[Test]
+	[Category(UITestCategories.Entry)]
+	public void ValidateEntryClearButtonVisibilityBehavior()
+	{
+		App.WaitForElement("TestInstructions");
+
+		// Click the button to add dynamically Entry3.
+		App.Click("AddEntry");
+
+		// Click the new entry to see if there is the clear button or not. No such button should be present.
+		App.Tap("Entry3");
+
+		VerifyScreenshot();
+	}
+#endif
+}

src/Core/src/Platform/Windows/MauiTextBox.cs

@@ -1,6 +1,6 @@
-#nullable enable
-using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Media;
 
 namespace Microsoft.Maui.Platform
 {
@@ -9,8 +9,6 @@ public static class MauiTextBox
 		const string ContentElementName = "ContentElement";
 		const string PlaceholderTextContentPresenterName = "PlaceholderTextContentPresenter";
 		const string DeleteButtonElementName = "DeleteButton";
-		const string ButtonStatesName = "ButtonStates";
-		const string ButtonVisibleStateName = "ButtonVisible";
 
 		public static void InvalidateAttachedProperties(DependencyObject obj)
 		{
@@ -39,15 +37,17 @@ static void OnVerticalTextAlignmentPropertyChanged(DependencyObject d, Dependenc
 
 			var scrollViewer = element?.GetDescendantByName<ScrollViewer>(ContentElementName);
 			if (scrollViewer is not null)
+			{
 				scrollViewer.VerticalAlignment = verticalAlignment;
+			}
 
 			var placeholder = element?.GetDescendantByName<TextBlock>(PlaceholderTextContentPresenterName);
 			if (placeholder is not null)
+			{
 				placeholder.VerticalAlignment = verticalAlignment;
+			}
 		}
 
-		// IsDeleteButtonEnabled
-
 		public static bool GetIsDeleteButtonEnabled(DependencyObject obj) =>
 			(bool)obj.GetValue(IsDeleteButtonEnabledProperty);
 
@@ -60,56 +60,25 @@ public static void SetIsDeleteButtonEnabled(DependencyObject obj, bool value) =>
 
 		static void OnIsDeleteButtonEnabledPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs? e = null)
 		{
-			// TODO: cache the buttonStates and buttonVisibleState values on the textBox
-
-			var element = d as FrameworkElement;
-
-			VisualStateGroup? buttonStates = null;
-			VisualState? buttonVisibleState = null;
-			var deleteButton = element?.GetDescendantByName<Button>(DeleteButtonElementName);
-			if (deleteButton?.Parent is Grid rootGrid)
-				(buttonStates, buttonVisibleState) = InterceptDeleteButtonVisualStates(rootGrid);
-
-			var states = buttonStates?.States;
-			if (element is not null && states is not null && buttonVisibleState is not null)
+			if (d is not FrameworkElement element)
 			{
-				var isEnabled = GetIsDeleteButtonEnabled(element);
-				var contains = states.Contains(buttonVisibleState);
-				if (isEnabled && !contains)
-					states.Add(buttonVisibleState);
-				else if (!isEnabled && contains)
-					states.Remove(buttonVisibleState);
+				return;
 			}
-		}
 
-		static (VisualStateGroup? Group, VisualState? State) InterceptDeleteButtonVisualStates(FrameworkElement? element)
-		{
-			// not the content we expected
-			if (element is null)
-				return (null, null);
-
-			// find "ButtonStates"
-			var visualStateGroups = VisualStateManager.GetVisualStateGroups(element);
-			VisualStateGroup? buttonStates = null;
-			foreach (var group in visualStateGroups)
-			{
-				if (group.Name == ButtonStatesName)
-					buttonStates = group;
-			}
-
-			// no button states
-			if (buttonStates is null)
-				return (null, null);
+			Button? deleteButton = element.GetDescendantByName<Button>(DeleteButtonElementName);
 
-			// find and return the "ButtonVisible" state
-			foreach (var state in buttonStates.States)
+			if (deleteButton is not null)
 			{
-				if (state.Name == ButtonVisibleStateName)
-					return (buttonStates, state);
+				if (GetIsDeleteButtonEnabled(element))
+				{
+					deleteButton.RenderTransform = null;
+				}
+				else
+				{
+					// This is a workaround to move the button to be effectively invisible. It is not perfect.
+					deleteButton.RenderTransform = new TranslateTransform() { X = -int.MaxValue, Y = -int.MaxValue };
+				}
 			}
-
-			// no button visible state
-			return (null, null);
 		}
 	}
 }