[iOS] NavigationPage: Fix large-title collapse for wrapped scroll content

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue33037NonShell.cs

@@ -0,0 +1,190 @@
+#if IOS
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue33037NonShell : _IssuesUITest
+{
+	public Issue33037NonShell(TestDevice testDevice) : base(testDevice)
+	{
+	}
+
+	public override string Issue => "iOS Large Title display disappears when scrolling in non-Shell NavigationPage";
+
+	[Test]
+	[Category(UITestCategories.Navigation)]
+	[TestCase("Issue33037ScrollViewButton", "Issue33037ScrollViewScroller", "Issue33037 Direct", "Item 40", "DirectScrollView", null)]
+	[TestCase("Issue33037GridScrollViewButton", "Issue33037GridScrollViewScroller", "Issue33037 Grid", "Item 40", "GridScrollView", null)]
+	[TestCase("Issue33037ContentViewGridScrollViewButton", "Issue33037ContentViewGridScrollViewScroller", "Issue33037 Wrapped", "Item 40", "ContentViewGridScrollView", null)]
+	[TestCase("Issue33037DynamicContentViewGridScrollViewButton", "Issue33037DynamicContentViewGridScrollViewScroller", "Issue33037 Dynamic", "Item 40", "DynamicContentViewGridScrollView", null)]
+	[TestCase("Issue33037ListViewButton", "Issue33037ListViewScroller", "Issue33037 List", "Item 40", "ListView", null)]
+	[TestCase("Issue33037CollectionViewButton", "Issue33037CollectionViewScroller", "Issue33037 Collection", "Item 40", "CollectionView", null)]
+	[TestCase("Issue33037TableViewButton", "Issue33037TableViewScroller", "Issue33037 Table", "Item 40", null, null)]
+	[TestCase("Issue33037CandidateSelectionButton", "Issue33037CandidateSelectionScroller", "Issue33037 Candidates", "Item 40", null, null)]
+	[TestCase("Issue33037FixedHeaderCollectionViewButton", "Issue33037FixedHeaderCollectionViewScroller", "Issue33037 Fixed Header", "Item 40", "FixedHeaderCollectionView", "Issue33037FixedHeader")]
+	[TestCase("Issue33037ShortFixedHeaderCollectionViewButton", "Issue33037ShortFixedHeaderCollectionViewScroller", "Issue33037 Short Header", "Item 16", null, "Issue33037ShortFixedHeader")]
+	public void LargeTitleCollapsesToVisibleStandardTitle(string buttonId, string scrollerId, string title, string targetItem, string scenarioName, string fixedHeaderId)
+	{
+		RequireIOS26OrHigher();
+		App.WaitForElement(buttonId).Click();
+
+		try
+		{
+			var expandedTitleRect = App.WaitForElement(title).GetRect();
+			App.WaitForElement(scrollerId);
+
+			if (buttonId == "Issue33037GridScrollViewButton")
+			{
+				VerifyScreenshot(
+					"Issue33037NonShell_GridScrollView_BeforeScroll",
+					tolerance: 0.5,
+					retryTimeout: TimeSpan.FromSeconds(2));
+			}
+
+			App.ScrollDown(scrollerId, swipePercentage: 0.8);
+			App.ScrollDown(scrollerId, swipePercentage: 0.8);
+			App.WaitForElement(targetItem);
+
+			var collapsedTitle = App.WaitForElement(title, $"Timed out waiting for collapsed title '{title}'");
+			var collapsedTitleRect = collapsedTitle.GetRect();
+
+			Assert.That(collapsedTitleRect.Height, Is.GreaterThan(0),
+				$"The '{title}' navigation title should remain visible in the standard navigation bar after collapsing.");
+			Assert.That(collapsedTitleRect.Height, Is.LessThan(expandedTitleRect.Height),
+				$"The '{title}' navigation title should be shorter after the nested scroller moves.");
+			Assert.That(collapsedTitleRect.Height, Is.LessThan(60),
+				$"The '{title}' navigation title should use the collapsed standard-title size.");
+			Assert.That(collapsedTitleRect.Y, Is.LessThan(130),
+				$"The '{title}' navigation title should remain in the navigation bar after collapsing.");
+
+			if (!string.IsNullOrEmpty(fixedHeaderId))
+			{
+				var fixedHeaderRect = App.WaitForElement(fixedHeaderId).GetRect();
+				Assert.That(fixedHeaderRect.Y, Is.GreaterThanOrEqualTo(collapsedTitleRect.Y + collapsedTitleRect.Height - 2),
+					"The fixed header should remain below the collapsed navigation title.");
+			}
+
+			if (!string.IsNullOrEmpty(scenarioName))
+			{
+				VerifyScreenshot(
+					$"Issue33037NonShell_{scenarioName}_AfterScroll",
+					cropBottom: fixedHeaderId is null ? 0 : 2016,
+					tolerance: fixedHeaderId is null ? 0.5 : 1.5,
+					retryTimeout: TimeSpan.FromSeconds(2));
+			}
+		}
+		finally
+		{
+			App.Back();
+		}
+	}
+
+	[Test]
+	[Category(UITestCategories.Navigation)]
+	public void ProgrammaticWebViewScrollCollapsesLargeTitle()
+	{
+		RequireIOS26OrHigher();
+		App.WaitForElement("Issue33037WebViewButton").Click();
+
+		try
+		{
+			App.WaitForElement("Ready");
+			var expandedTitleRect = App.WaitForElement("Issue33037 Web").GetRect();
+
+			App.WaitForElement("Issue33037WebViewScrollButton").Click();
+			App.WaitForElement("Scrolled");
+
+			var collapsedTitleRect = App.WaitForElement("Issue33037 Web").GetRect();
+			Assert.That(collapsedTitleRect.Height, Is.LessThan(expandedTitleRect.Height),
+				"The navigation title should be shorter after the wrapped WebView scrolls.");
+			Assert.That(collapsedTitleRect.Height, Is.LessThan(60),
+				"The navigation title should collapse after the wrapped WebView scrolls.");
+		}
+		finally
+		{
+			App.Back();
+		}
+	}
+
+	[Test]
+	[Category(UITestCategories.Navigation)]
+	public void ProgrammaticScrollCollapsesLargeTitle()
+	{
+		RequireIOS26OrHigher();
+		App.WaitForElement("Issue33037ProgrammaticCollectionViewButton").Click();
+
+		try
+		{
+			App.WaitForElement("Issue33037ProgrammaticCollectionViewScroller");
+			var expandedTitleRect = App.WaitForElement("Issue33037 Programmatic").GetRect();
+
+			App.WaitForElement("Issue33037ProgrammaticScrollButton").Click();
+			App.WaitForElement("Item 50");
+
+			var collapsedTitleRect = App.WaitForElement("Issue33037 Programmatic").GetRect();
+			Assert.That(collapsedTitleRect.Height, Is.LessThan(expandedTitleRect.Height),
+				"The navigation title should be shorter after CollectionView.ScrollTo changes the wrapped scroller offset.");
+			Assert.That(collapsedTitleRect.Height, Is.LessThan(60),
+				"The navigation title should collapse after CollectionView.ScrollTo changes the wrapped scroller offset.");
+		}
+		finally
+		{
+			App.Back();
+		}
+	}
+
+	[Test]
+	[Category(UITestCategories.Navigation)]
+	public void OnAppearingProgrammaticScrollCollapsesLargeTitle()
+	{
+		RequireIOS26OrHigher();
+		App.WaitForElement("Issue33037AppearingCollectionViewButton").Click();
+
+		try
+		{
+			App.WaitForElement("Issue33037AppearingCollectionViewScroller");
+			App.WaitForElement("Item 50");
+
+			var collapsedTitleRect = App.WaitForElement("Issue33037 Appearing").GetRect();
+			Assert.That(collapsedTitleRect.Height, Is.LessThan(60),
+				"The navigation title should collapse when CollectionView.ScrollTo runs during OnAppearing.");
+
+			VerifyScreenshot(
+				"Issue33037NonShell_AppearingCollectionView_AfterScroll",
+				tolerance: 0.5,
+				retryTimeout: TimeSpan.FromSeconds(2));
+		}
+		finally
+		{
+			App.Back();
+		}
+	}
+
+	[Test]
+	[Category(UITestCategories.Navigation)]
+	public void HiddenNavigationBarPreservesTopSafeArea()
+	{
+		RequireIOS26OrHigher();
+		App.WaitForElement("Issue33037HiddenNavigationBarButton").Click();
+
+		try
+		{
+			var topMarker = App.WaitForElement("Issue33037HiddenNavigationBarTopMarker").GetRect();
+			Assert.That(topMarker.Y, Is.GreaterThan(20),
+				"Content should remain below the status bar when the navigation bar is hidden.");
+		}
+		finally
+		{
+			App.WaitForElement("Issue33037HiddenNavigationBarBackButton").Click();
+		}
+	}
+
+	void RequireIOS26OrHigher()
+	{
+		if (App is not AppiumIOSApp iosApp || !HelperExtensions.IsIOS26OrHigher(iosApp))
+			Assert.Ignore("Issue #33037 only affects iOS 26 and later.");
+	}
+}
+#endif