[Android] SafeArea: Skip RequestApplyInsets for completely off-screen views

.github/copilot-instructions.md

@@ -98,6 +98,35 @@ Always format code before committing:
 dotnet format Microsoft.Maui.sln --no-restore --exclude Templates/src --exclude-diagnostics CA1822
 ```
 
+### Code Style Anti-Patterns
+
+**🚨 NEVER use these patterns:**
+
+| Anti-Pattern | Why It's Bad | Correct Approach |
+|--------------|--------------|------------------|
+| `obj.GetType().Name` | Fragile, breaks with refactoring, violates OOP | Use marker interfaces |
+| `obj.GetType() == typeof(X)` | Same issues, also breaks inheritance | Use `is` operator with interfaces |
+| `typeName.EndsWith("Page")` | String-based type checking is error-prone | Create internal marker interface |
+| `obj.GetType().FullName.Contains("...")` | Extremely fragile, namespace changes break it | Use interfaces or base classes |
+
+**Correct pattern for type-specific behavior:**
+
+```csharp
+// ❌ BAD - Never do this
+if (obj.GetType().Name.EndsWith("ContentPage"))
+
+// ✅ GOOD - Use marker interface
+internal interface IContentPageController { }
+public partial class ContentPage : IContentPageController { }
+
+if (obj is IContentPageController)
+```
+
+When you need platform-specific type checking:
+1. Create an internal marker interface in `src/Core/src/Platform/{Platform}/`
+2. Have the specific type implement the interface (use platform-specific partial if needed)
+3. Check for the interface using `is` operator
+
 ## Contribution Guidelines
 
 ### Handling Existing PRs for Assigned Issues

src/Controls/src/Core/Compatibility/Handlers/Shell/Android/ShellFlyoutRenderer.cs

@@ -17,7 +17,7 @@
 
 namespace Microsoft.Maui.Controls.Platform.Compatibility
 {
-	public class ShellFlyoutRenderer : DrawerLayout, IShellFlyoutRenderer, IFlyoutBehaviorObserver, IAppearanceObserver
+	public class ShellFlyoutRenderer : DrawerLayout, IShellFlyoutRenderer, IFlyoutBehaviorObserver, IAppearanceObserver, Microsoft.Maui.Platform.IRequestInsetsOnTransition
 	{
 		#region IAppearanceObserver
 

src/Controls/src/Core/ContentPage/ContentPage.Android.cs

@@ -0,0 +1,9 @@
+#nullable enable
+namespace Microsoft.Maui.Controls
+{
+	// Android-specific partial for ContentPage
+	// Implements IContentPageController marker interface for safe area transition handling
+	public partial class ContentPage : Microsoft.Maui.Platform.IContentPageController
+	{
+	}
+}

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

@@ -0,0 +1,111 @@
+#nullable enable
+using System.Diagnostics;
+
+namespace Maui.Controls.Sample;
+
+/// <summary>
+/// A lightweight service that logs GC activity to Console.WriteLine for test infrastructure.
+/// 
+/// This service runs automatically on Android and logs GC counts with the [MAUI_GC] prefix.
+/// The UITest infrastructure can parse these logs from logcat to track GC activity per test.
+/// 
+/// Since the app resets between test runs, GC counts are tracked from app startup,
+/// giving us a clean per-test baseline.
+/// </summary>
+public static class GCMonitoringService
+{
+	private static int _initialGen0Count;
+	private static int _initialGen1Count;
+	private static int _initialGen2Count;
+	private static DateTime _startTime;
+	private static bool _isInitialized;
+	private static string? _currentTestPage;
+
+	/// <summary>
+	/// Initialize the GC monitoring service. Call once at app startup.
+	/// </summary>
+	public static void Initialize()
+	{
+		if (_isInitialized)
+			return;
+
+		// Force a GC to establish clean baseline
+		GC.Collect();
+		GC.WaitForPendingFinalizers();
+		GC.Collect();
+
+		_initialGen0Count = GC.CollectionCount(0);
+		_initialGen1Count = GC.CollectionCount(1);
+		_initialGen2Count = GC.CollectionCount(2);
+		_startTime = DateTime.UtcNow;
+		_isInitialized = true;
+
+		Log($"Initialized at {_startTime:HH:mm:ss.fff}, baseline Gen0={_initialGen0Count}, Gen1={_initialGen1Count}, Gen2={_initialGen2Count}");
+	}
+
+	/// <summary>
+	/// Log when a test page is navigated to. Helps correlate GC activity with specific tests.
+	/// </summary>
+	public static void OnTestPageNavigated(string pageName)
+	{
+		if (!_isInitialized)
+			Initialize();
+
+		_currentTestPage = pageName;
+		var (gen0, gen1, gen2) = GetCurrentCounts();
+		Log($"TestPage={pageName}, Gen0={gen0}, Gen1={gen1}, Gen2={gen2}");
+	}
+
+	/// <summary>
+	/// Log when a test page is left. Shows GC activity during the test.
+	/// </summary>
+	public static void OnTestPageLeft(string pageName)
+	{
+		if (!_isInitialized)
+			return;
+
+		var (gen0, gen1, gen2) = GetCurrentCounts();
+		var elapsed = (DateTime.UtcNow - _startTime).TotalSeconds;
+		Log($"TestPageLeft={pageName}, Gen0={gen0}, Gen1={gen1}, Gen2={gen2}, ElapsedSec={elapsed:F1}");
+		_currentTestPage = null;
+	}
+
+	/// <summary>
+	/// Log current GC counts. Can be called at any time for debugging.
+	/// </summary>
+	public static void LogCurrentState(string? context = null)
+	{
+		if (!_isInitialized)
+			Initialize();
+
+		var (gen0, gen1, gen2) = GetCurrentCounts();
+		var elapsed = (DateTime.UtcNow - _startTime).TotalSeconds;
+		var ctx = context ?? _currentTestPage ?? "Unknown";
+		Log($"State={ctx}, Gen0={gen0}, Gen1={gen1}, Gen2={gen2}, ElapsedSec={elapsed:F1}");
+	}
+
+	/// <summary>
+	/// Get GC counts since initialization.
+	/// </summary>
+	public static (int Gen0, int Gen1, int Gen2) GetCurrentCounts()
+	{
+		if (!_isInitialized)
+			Initialize();
+
+		return (
+			GC.CollectionCount(0) - _initialGen0Count,
+			GC.CollectionCount(1) - _initialGen1Count,
+			GC.CollectionCount(2) - _initialGen2Count
+		);
+	}
+
+	/// <summary>
+	/// Log with the [MAUI_GC] prefix that the test infrastructure will parse.
+	/// </summary>
+	private static void Log(string message)
+	{
+		// Use Console.WriteLine which goes to logcat on Android
+		// The [MAUI_GC] prefix allows the test infrastructure to easily grep these entries
+		Console.WriteLine($"[MAUI_GC] {message}");
+	}
+}

src/Controls/tests/TestCases.HostApp/Issues/Issue33731.cs

@@ -0,0 +1,187 @@
+#nullable enable
+namespace Maui.Controls.Sample.Issues;
+
+/// <summary>
+/// Test for Issue #33731 - Continuous GC logs on TabbedPage in MAUI 10.0.30.
+/// 
+/// The bug causes an infinite loop of RequestApplyInsets calls when Tab 2's content
+/// is positioned off-screen (at x=screenWidth). This creates continuous lambda
+/// allocations (~60/sec), triggering GC every ~5-6 seconds.
+/// 
+/// This test monitors GC.CollectionCount(0) to detect excessive GC activity.
+/// WITH BUG: 5+ GC events in 30 seconds
+/// WITH FIX: 0-1 GC events in 30 seconds
+/// </summary>
+[Issue(IssueTracker.Github, 33731, "Continuous GC logs on TabbedPage in MAUI 10.0.30", PlatformAffected.Android)]
+public class Issue33731 : TabbedPage
+{
+	private readonly Label _gcCountLabel;
+	private readonly Label _statusLabel;
+	private int _lastGcCount;
+	private int _gcEventsDetected;
+	private DateTime _startTime;
+	private IDispatcherTimer? _timer;
+
+	public Issue33731()
+	{
+		AutomationId = "TabbedPageRoot";
+
+		// Force initial GC to establish baseline
+		GC.Collect();
+		GC.WaitForPendingFinalizers();
+		GC.Collect();
+
+		_lastGcCount = GC.CollectionCount(0);
+		_gcEventsDetected = 0;
+		_startTime = DateTime.UtcNow;
+
+		// Create the monitoring UI on Tab 1
+		_gcCountLabel = new Label
+		{
+			AutomationId = "GCCountLabel",
+			Text = "GCCount: 0",
+			FontSize = 24,
+			FontAttributes = FontAttributes.Bold,
+			BackgroundColor = Colors.Yellow,
+			HorizontalOptions = LayoutOptions.Center,
+			Padding = new Thickness(10)
+		};
+
+		_statusLabel = new Label
+		{
+			AutomationId = "StatusLabel",
+			Text = "Monitoring...",
+			FontSize = 16,
+			HorizontalOptions = LayoutOptions.Center
+		};
+
+		var tab1 = new ContentPage
+		{
+			Title = "GC Monitor",
+			Content = new VerticalStackLayout
+			{
+				Padding = 20,
+				Spacing = 10,
+				Children =
+				{
+					new Label 
+					{ 
+						Text = "Issue #33731 - TabbedPage GC Monitor", 
+						AutomationId = "Tab1Label",
+						FontSize = 18, 
+						FontAttributes = FontAttributes.Bold, 
+						HorizontalOptions = LayoutOptions.Center 
+					},
+					new BoxView { HeightRequest = 2, Color = Colors.Gray },
+					_gcCountLabel,
+					_statusLabel,
+					new Label
+					{
+						Text = "WITH BUG: GCCount increases rapidly (5+ in 30s)\n" +
+						       "WITH FIX: GCCount stays at 0-1",
+						FontSize = 12,
+						HorizontalOptions = LayoutOptions.Center,
+						Margin = new Thickness(0, 20, 0, 0)
+					}
+				}
+			}
+		};
+
+		// Create second tab with Grid (matching the exact repro from the issue)
+		var tab2 = new ContentPage
+		{
+			Title = "Tab 2",
+			Content = new Grid
+			{
+				Children =
+				{
+					new Label
+					{
+						Text = "Tab 2 - Inactive tab",
+						AutomationId = "Tab2Label",
+						HorizontalOptions = LayoutOptions.Center,
+						VerticalOptions = LayoutOptions.Center,
+						FontSize = 24
+					}
+				}
+			}
+		};
+
+		// Create third tab (more tabs = higher likelihood of bug triggering)
+		var tab3 = new ContentPage
+		{
+			Title = "Tab 3",
+			Content = new Grid
+			{
+				Children =
+				{
+					new Label
+					{
+						Text = "Tab 3 - Another inactive tab",
+						HorizontalOptions = LayoutOptions.Center,
+						VerticalOptions = LayoutOptions.Center,
+						FontSize = 24
+					}
+				}
+			}
+		};
+
+		Children.Add(tab1);
+		Children.Add(tab2);
+		Children.Add(tab3);
+
+		// Start GC monitoring timer
+		_timer = Application.Current?.Dispatcher.CreateTimer();
+		if (_timer != null)
+		{
+			_timer.Interval = TimeSpan.FromMilliseconds(500);
+			_timer.Tick += OnTimerTick;
+			_timer.Start();
+		}
+	}
+
+	private void OnTimerTick(object? sender, EventArgs e)
+	{
+		int currentGcCount = GC.CollectionCount(0);
+
+		if (currentGcCount > _lastGcCount)
+		{
+			int newGCs = currentGcCount - _lastGcCount;
+			_gcEventsDetected += newGCs;
+			_lastGcCount = currentGcCount;
+		}
+
+		// Update UI - format must match what the test expects: "GCCount: X"
+		_gcCountLabel.Text = $"GCCount: {_gcEventsDetected}";
+
+		// Calculate elapsed time
+		double elapsedSeconds = (DateTime.UtcNow - _startTime).TotalSeconds;
+
+		// Update status based on results
+		if (elapsedSeconds >= 30)
+		{
+			if (_gcEventsDetected >= 5)
+			{
+				_statusLabel.Text = $"BUG DETECTED: {_gcEventsDetected} GCs in {elapsedSeconds:F0}s";
+			}
+			else if (_gcEventsDetected <= 1)
+			{
+				_statusLabel.Text = $"PASS: Only {_gcEventsDetected} GCs in {elapsedSeconds:F0}s";
+			}
+			else
+			{
+				_statusLabel.Text = $"BORDERLINE: {_gcEventsDetected} GCs in {elapsedSeconds:F0}s";
+			}
+		}
+		else
+		{
+			_statusLabel.Text = $"Monitoring... {elapsedSeconds:F0}s elapsed";
+		}
+	}
+
+	protected override void OnDisappearing()
+	{
+		base.OnDisappearing();
+		_timer?.Stop();
+	}
+}