[iOS] Fix Span TapGestureRecognizer hitbox misalignment in FormattedString when font contains a STAT table

src/Controls/src/Core/Platform/iOS/Extensions/FormattedStringExtensions.cs

@@ -220,16 +220,29 @@ internal static void RecalculateSpanPositions(this UILabel control, Label elemen
 			nint NSMaxRange(NSRange range) => range.Location + range.Length;
 
 			using var textStorage = new NSTextStorage();
-			using var layoutManager = new NSLayoutManager();
+			// On iOS 16+, NSLayoutManager's default UsesFontLeading=true causes it to include
+			// font leading (extra line spacing) from the OS/2 typographic metrics that CoreText
+			// uses when a font has an OpenType STAT table. This makes the layout manager compute
+			// line heights that don't match what CoreText uses to draw the glyphs, resulting in
+			// span tap hitboxes being vertically offset from the rendered text.
+			// Disabling UsesFontLeading on iOS 16+ makes NSLayoutManager match CoreText's metrics
+			// so the calculated span rects align with the actual rendered text positions.
+			// See: https://github.com/dotnet/maui/issues/36505
+			using var layoutManager = new NSLayoutManager
+			{
+				UsesFontLeading = !OperatingSystem.IsIOSVersionAtLeast(16)
+			};
 			using var textContainer = new NSTextContainer { LineFragmentPadding = 0 };
 
 			textStorage.AddLayoutManager(layoutManager);
 			layoutManager.AddTextContainer(textContainer);
 
-			// On iOS 26+ with NavigationPage, UILabel.Bounds may still be {0,0,0,0}
-			// during ArrangeOverride. Use finalSize (MAUI's computed size) as fallback.
-			var containerWidth = control.Bounds.Width > 0 ? control.Bounds.Width : (nfloat)finalSize.Width;
-			var containerHeight = control.Bounds.Height > 0 ? control.Bounds.Height : (nfloat)finalSize.Height;
+			// Always prefer finalSize from MAUI's layout system — it is the authoritative
+			// size for this arrange pass. On Mac Catalyst (and iOS 26+ with NavigationPage),
+			// control.Bounds may be stale or {0,0,0,0} during ArrangeOverride because UIKit
+			// frame updates can lag behind MAUI's layout.
+			var containerWidth = (nfloat)finalSize.Width > 0 ? (nfloat)finalSize.Width : control.Bounds.Width;
+			var containerHeight = (nfloat)finalSize.Height > 0 ? (nfloat)finalSize.Height : control.Bounds.Height;
 			textContainer.Size = new(containerWidth, control.Lines == 0 ? nfloat.MaxValue : containerHeight);
 
 			textStorage.SetString(attributedText);

src/Controls/tests/TestCases.HostApp/Issues/Issue36505.cs

@@ -0,0 +1,67 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 36505,
+    "[iOS] Span TapGestureRecognizer hitbox is mispositioned inside FormattedString when the font contains a STAT table (line-height/leading mismatch)",
+    PlatformAffected.iOS | PlatformAffected.macOS)]
+public class Issue36505 : ContentPage
+{
+    public Issue36505()
+    {
+        var statusLabel = new Label
+        {
+            AutomationId = "StatusLabel",
+            Text = "Not tapped",
+        };
+
+        void OnSpanTapped(object sender, TappedEventArgs e)
+        {
+            statusLabel.Text = "Success";
+        }
+
+        var fs = new FormattedString();
+
+        fs.Spans.Add(new Span
+        {
+            Text = "Line 1.\nLine 2.\nLine 3.\nLine 4.\nLine 5.\n"
+                 + "Line 6.\nLine 7.\nLine 8.\nLine 9.\nLine 10.\n"
+                 + "Line 11.\nLine 12.\nLine 13.\nLine 14.\nLine 15.\n",
+            FontFamily = "MyCustomFont",
+            FontSize = 16,
+        });
+
+        var tappableSpan = new Span
+        {
+            Text = "Click me",
+            FontFamily = "MyCustomFont",
+            FontSize = 16,
+            TextColor = Colors.Blue,
+            TextDecorations = TextDecorations.Underline,
+        };
+        var tapRecognizer = new TapGestureRecognizer();
+        tapRecognizer.Tapped += OnSpanTapped;
+        tappableSpan.GestureRecognizers.Add(tapRecognizer);
+        fs.Spans.Add(tappableSpan);
+
+        var spanLabel = new Label
+        {
+            AutomationId = "SpanLabel",
+            FormattedText = fs,
+            LineBreakMode = LineBreakMode.WordWrap,
+        };
+
+        var lineRefLabel = new Label
+        {
+            AutomationId = "LineRef",
+            Text = "Reference line",
+            FontFamily = "MyCustomFont",
+            FontSize = 16,
+        };
+
+        Content = new VerticalStackLayout
+        {
+            Padding = new Thickness(20),
+            Spacing = 20,
+            Children = { spanLabel, lineRefLabel, statusLabel }
+        };
+    }
+}

src/Controls/tests/TestCases.HostApp/MauiProgram.cs

@@ -33,6 +33,7 @@ public static MauiApp CreateMauiApp()
 					fonts.AddFont("FontAwesome.ttf", "FA");
 					fonts.AddFont("ionicons.ttf", "Ion");
 					fonts.AddFont("Montserrat-Bold.otf", "MontserratBold");
+					fonts.AddFont("MyCustomFont.ttf", "MyCustomFont");
 				})
 				.RenderingPerformanceAddMappers()
 				.Issue21109AddMappers()

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue36505.cs

@@ -0,0 +1,47 @@
+#if IOS || MACCATALYST   // This issue is only reproducible on iOS and MacCatalyst, so skip the test on other platforms.
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue36505 : _IssuesUITest
+{
+	public Issue36505(TestDevice device) : base(device) { }
+
+	public override string Issue =>
+		"[iOS] Span TapGestureRecognizer hitbox is mispositioned inside FormattedString when the font contains a STAT table (line-height/leading mismatch)";
+
+	[Test]
+	[Category(UITestCategories.Label)]
+	public void SpanTapHitboxShouldAlignWithRenderedTextWhenFontHasStatTable()
+	{
+		var label = App.WaitForElement("SpanLabel");
+		var location = label.GetRect();
+
+		// LineRef is a standalone single-line label with the same font and size.
+		// Its height = pure visual line height (UILabel, no leading on iOS 16+).
+		var visualLineHeight = App.WaitForElement("LineRef").GetRect().Height;
+		var lineCenterOffset = visualLineHeight / 2;
+		var y = location.Y;
+
+		// Tap "Click me" (line 16) at its visual centre.
+		// On MacCatalyst the rendered position is slightly higher, so shift up by
+		// half a visual line to land reliably on the tappable span.
+		TapClickMe(location.X + 10, y, visualLineHeight, lineCenterOffset);
+
+		Assert.That(App.WaitForTextToBePresentInElement("StatusLabel", "Success", timeout: TimeSpan.FromSeconds(3)),
+			Is.True,
+			"Tapping the span at its visual position should trigger the TapGestureRecognizer");
+	}
+
+	void TapClickMe(float x, float y, float visualLineHeight, float lineCenterOffset)
+	{
+#if MACCATALYST
+			App.TapCoordinates(x, y + (visualLineHeight * 15) + lineCenterOffset - visualLineHeight * 0.5f);
+#else
+			App.TapCoordinates(x, y + (visualLineHeight * 15) + lineCenterOffset);
+#endif
+	}
+}
+#endif