- unit tests

Xamarin.Forms.Platform.Android.UnitTests/ShellTests.cs

@@ -13,10 +13,43 @@
 using NUnit.Framework;
 using Xamarin.Forms.CustomAttributes;
 
+[assembly: ExportRenderer(typeof(TestShell), typeof(TestShellRenderer))]
 namespace Xamarin.Forms.Platform.Android.UnitTests
 {
 	public class ShellTests : PlatformTestFixture
 	{
+		[Test, Category("Shell")]
+		[Description("Flyout Header Changes When Updated")]
+		public async Task FlyoutHeaderReactsToChanges()
+		{
+			var shell = CreateShell();
+			var initialHeader = new Label() { Text = "Hello" };
+			var newHeader = new Label() { Text = "Hello part 2" };
+			shell.FlyoutHeader = initialHeader;
+			var addedView = await Device.InvokeOnMainThreadAsync(() =>
+			{
+				var r = GetRenderer(shell);
+				var window = (Context.GetActivity()).Window;
+				(window.DecorView as global::Android.Views.ViewGroup).AddView(r.View);
+				return r.View;
+			});
+
+			try
+			{
+				Assert.IsNotNull(addedView);
+				Assert.IsNull(newHeader.GetValue(Platform.RendererProperty));
+				Assert.IsNotNull(initialHeader.GetValue(Platform.RendererProperty));
+				await Device.InvokeOnMainThreadAsync(() => shell.FlyoutHeader = newHeader);
+
+				Assert.IsNotNull(newHeader.GetValue(Platform.RendererProperty), "New Header Not Set Up");
+				Assert.IsNull(initialHeader.GetValue(Platform.RendererProperty), "Old Header Still Set Up");
+			}
+			finally
+			{
+				await Device.InvokeOnMainThreadAsync(() => addedView?.RemoveFromParent());
+			}
+		}
+
 		[Test, Category("Shell")]
 		[Description("Ensure Default Colors are White for BottomNavigationView")]
 		public async Task ShellTabColorsDefaultToWhite()
@@ -47,6 +80,7 @@ public class ShellAppearanceTest : IShellAppearanceElement
 
 			public Color EffectiveTabBarUnselectedColor { get; set; }
 		}
+
 		Shell CreateShell()
 		{
 			return new Shell()
@@ -73,4 +107,31 @@ Shell CreateShell()
 			};
 		}
 	}
-}
+
+	public class TestShell : Shell { }
+
+	public class ShellAppearanceTest : IShellAppearanceElement
+	{
+		public Color EffectiveTabBarBackgroundColor { get; set; }
+
+		public Color EffectiveTabBarDisabledColor { get; set; }
+
+		public Color EffectiveTabBarForegroundColor { get; set; }
+
+		public Color EffectiveTabBarTitleColor { get; set; }
+
+		public Color EffectiveTabBarUnselectedColor { get; set; }
+	}
+
+	public class TestShellRenderer : ShellRenderer
+	{
+		protected override IShellFlyoutContentRenderer CreateShellFlyoutContentRenderer()
+		{
+			return base.CreateShellFlyoutContentRenderer();
+		}
+
+		public TestShellRenderer(Context context) : base(context)
+		{
+		}
+	}
+}

Xamarin.Forms.Platform.Android/Renderers/ShellFlyoutTemplatedContentRenderer.cs

@@ -77,21 +77,7 @@ protected virtual void LoadView(IShellContext shellContext)
 
 			Profile.FramePartition("Add HeaderView");
 			_actionBarHeight = (int)context.ToPixels(56);
-
-			_flyoutHeader = ((IShellController)shellContext.Shell).FlyoutHeader;
-			if (_flyoutHeader != null)
-				_flyoutHeader.MeasureInvalidated += OnFlyoutHeaderMeasureInvalidated;
-
-			_headerView = new HeaderContainer(context, _flyoutHeader)
-			{
-				MatchWidth = true
-			};
-			_headerView.SetMinimumHeight(_actionBarHeight);
-			_headerView.LayoutParameters = new AppBarLayout.LayoutParams(LP.MatchParent, LP.WrapContent)
-			{
-				ScrollFlags = AppBarLayout.LayoutParams.ScrollFlagScroll
-			};
-			_appBar.AddView(_headerView);
+			UpdateFlyoutHeader();
 
 			Profile.FramePartition("Recycler.SetAdapter");
 			_adapter = new ShellFlyoutRecyclerAdapter(shellContext, OnElementSelected);
@@ -155,6 +141,42 @@ protected virtual void OnShellPropertyChanged(object sender, PropertyChangedEven
 				UpdateFlyoutBackground();
 			else if (e.Is(Shell.FlyoutVerticalScrollModeProperty))
 				UpdateVerticalScrollMode();
+			else if (e.IsOneOf(
+				Shell.FlyoutHeaderProperty,
+				Shell.FlyoutHeaderTemplateProperty))
+				UpdateFlyoutHeader();
+		}
+
+		void UpdateFlyoutHeader()
+		{
+			if(_headerView != null)
+			{
+				var oldHeaderView = _headerView;
+				_headerView = null;
+				_appBar.RemoveView(oldHeaderView);
+				oldHeaderView.Dispose();
+			}
+
+			if (_flyoutHeader != null)
+			{
+				_flyoutHeader.MeasureInvalidated -= OnFlyoutHeaderMeasureInvalidated;
+			}
+
+			_flyoutHeader = ((IShellController)_shellContext.Shell).FlyoutHeader;
+			if (_flyoutHeader != null)
+				_flyoutHeader.MeasureInvalidated += OnFlyoutHeaderMeasureInvalidated;
+
+			_headerView = new HeaderContainer(_shellContext.AndroidContext, _flyoutHeader)
+			{
+				MatchWidth = true
+			};
+			_headerView.SetMinimumHeight(_actionBarHeight);
+			_headerView.LayoutParameters = new AppBarLayout.LayoutParams(LP.MatchParent, LP.WrapContent)
+			{
+				ScrollFlags = AppBarLayout.LayoutParams.ScrollFlagScroll
+			};
+			_appBar.AddView(_headerView);
+			UpdateFlyoutHeaderBehavior();
 		}
 
 		void UpdateVerticalScrollMode()

Xamarin.Forms.Platform.Android/Renderers/ShellRenderer.cs

@@ -275,7 +275,7 @@ protected virtual void SwitchFragment(FragmentManager manager, AView targetView,
 			var fragment = _currentRenderer.Fragment;
 
 			Profile.FramePartition("Transaction");
-			FragmentTransaction transaction = manager.BeginTransaction();
+			FragmentTransaction transaction = manager.BeginTransactionEx();
 
 			if (animate)
 				transaction.SetTransitionEx((int)global::Android.App.FragmentTransit.EnterMask);
@@ -428,7 +428,7 @@ protected virtual void Dispose(bool disposing)
 			{
 				if (_currentRenderer != null && _currentRenderer.Fragment.IsAlive())
 				{
-					FragmentTransaction transaction = FragmentManager.BeginTransaction();
+					FragmentTransaction transaction = FragmentManager.BeginTransactionEx();
 					transaction.RemoveEx(_currentRenderer.Fragment);
 					transaction.CommitAllowingStateLossEx();
 					FragmentManager.ExecutePendingTransactionsEx();