Fix Issue #1160 (#1234)

* Fixed code for Issue #1160

* Changed how to refer to Subviews

* Revert and deprecate RoundedStackView

src/CommunityToolkit.Maui.Core/Views/Alert/AlertView.macios.cs

@@ -83,16 +83,11 @@ void ConstraintInParent()
 	[MemberNotNull(nameof(Container))]
 	void Initialize()
 	{
-		Container = new RoundedStackView(
-			VisualOptions.CornerRadius.X,
-			VisualOptions.CornerRadius.Y,
-			VisualOptions.CornerRadius.Width,
-			VisualOptions.CornerRadius.Height)
+		Container = new UIStackView()
 		{
 			Alignment = UIStackViewAlignment.Fill,
 			Distribution = UIStackViewDistribution.EqualSpacing,
 			Axis = UILayoutConstraintAxis.Horizontal,
-			BackgroundColor = VisualOptions.BackgroundColor,
 			TranslatesAutoresizingMaskIntoConstraints = false
 		};
 
@@ -103,5 +98,16 @@ void Initialize()
 
 		TranslatesAutoresizingMaskIntoConstraints = false;
 		AddSubview(Container);
+
+		var subView = new RoundedView(
+			VisualOptions.CornerRadius.X,
+			VisualOptions.CornerRadius.Y,
+			VisualOptions.CornerRadius.Width,
+			VisualOptions.CornerRadius.Height)
+		{
+			BackgroundColor = VisualOptions.BackgroundColor,
+			AutoresizingMask = UIViewAutoresizing.FlexibleHeight | UIViewAutoresizing.FlexibleWidth
+		};
+		Subviews[0].InsertSubview(subView, atIndex: 0);
 	}
 }

src/CommunityToolkit.Maui.Core/Views/RoundedStackView.macios.cs

@@ -6,6 +6,7 @@ namespace CommunityToolkit.Maui.Core.Views;
 /// <summary>
 /// A rounded <see cref="UIStackView"/>
 /// </summary>
+[Obsolete]
 public class RoundedStackView : UIStackView
 {
 	/// <summary>

src/CommunityToolkit.Maui.Core/Views/RoundedView.macios.cs

@@ -0,0 +1,78 @@
+using System.Runtime.InteropServices;
+using CoreAnimation;
+
+namespace CommunityToolkit.Maui.Core.Views;
+
+/// <summary>
+/// A rounded <see cref="UIView"/>
+/// </summary>
+public class RoundedView : UIView
+{
+	/// <summary>
+	/// Initialize <see cref="RoundedView"/>
+	/// </summary>
+	public RoundedView(NFloat leftPadding, NFloat topPadding, NFloat rightPadding, NFloat bottomPadding)
+	{
+		LeftPadding = leftPadding;
+		TopPadding = topPadding;
+		RightPadding = rightPadding;
+		BottomPadding = bottomPadding;
+	}
+
+	/// <summary>
+	/// Left Padding
+	/// </summary>
+	public NFloat LeftPadding { get; }
+
+	/// <summary>
+	/// Top Padding
+	/// </summary>
+	public NFloat TopPadding { get; }
+
+	/// <summary>
+	/// Right Padding
+	/// </summary>
+	public NFloat RightPadding { get; }
+
+	/// <summary>
+	/// Bottom Padding
+	/// </summary>
+	public NFloat BottomPadding { get; }
+
+	/// <inheritdoc />
+	public override void Draw(CGRect rect)
+	{
+		ClipsToBounds = true;
+
+		var path = GetRoundedPath(rect, LeftPadding, TopPadding, RightPadding, BottomPadding);
+		var maskLayer = new CAShapeLayer
+		{
+			Frame = rect,
+			Path = path
+		};
+
+		Layer.Mask = maskLayer;
+		Layer.MasksToBounds = true;
+	}
+
+	static CGPath? GetRoundedPath(CGRect rect, NFloat left, NFloat top, NFloat right, NFloat bottom)
+	{
+		var path = new UIBezierPath();
+		path.MoveTo(new CGPoint(rect.Width - right, rect.Y));
+
+		path.AddArc(new CGPoint(rect.X + rect.Width - right, rect.Y + right), right, (NFloat)(Math.PI * 1.5), (NFloat)Math.PI * 2, true);
+		path.AddLineTo(new CGPoint(rect.Width, rect.Height - bottom));
+
+		path.AddArc(new CGPoint(rect.X + rect.Width - bottom, rect.Y + rect.Height - bottom), bottom, 0, (NFloat)(Math.PI * .5), true);
+		path.AddLineTo(new CGPoint(left, rect.Height));
+
+		path.AddArc(new CGPoint(rect.X + left, rect.Y + rect.Height - left), left, (NFloat)(Math.PI * .5), (NFloat)Math.PI, true);
+		path.AddLineTo(new CGPoint(rect.X, top));
+
+		path.AddArc(new CGPoint(rect.X + top, rect.Y + top), top, (NFloat)Math.PI, (NFloat)(Math.PI * 1.5), true);
+
+		path.ClosePath();
+
+		return path.CGPath;
+	}
+}