894511 : Shell Tab is still visible after set Tab.IsVisible to false (#24161)

* 894511 : Shell Tab is still visible after set Tab.IsVisible to false

* Commit for test cases changes

* 894511 : Review changes

* Commit for testcase changes

* Commit for proper flyout width

* Review changes

* Image added

* 894511 : Commit for windows

* 894511 : Fix for iOS included

* Fix: 894511 : Review changes

* Fix:894511 : Images Added

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

@@ -295,7 +295,13 @@ namespace Microsoft.Maui.Controls.Platform.Compatibility
 				oldPage.PropertyChanged -= OnDisplayedElementPropertyChanged;
 
 			if (newPage is not null)
+			{
 				newPage.PropertyChanged += OnDisplayedElementPropertyChanged;
+				if (oldPage is null)
+				{
+					_menuSetup = false;
+				}
+			}
 
 			if (newPage is not null && !_menuSetup)
 			{

src/Controls/src/Core/Compatibility/Handlers/Shell/iOS/ShellItemRenderer.cs

@@ -357,6 +357,10 @@ namespace Microsoft.Maui.Controls.Platform.Compatibility
 			if (shellSection == null || _currentSection == shellSection)
 				return;
 			var renderer = RendererForShellContent(shellSection);
+			
+			if (renderer == null)
+				return;
+
 			if (renderer?.ViewController != SelectedViewController)
 				SelectedViewController = renderer.ViewController;
 			CurrentRenderer = renderer;

src/Controls/src/Core/Handlers/Shell/ShellItemHandler.Windows.cs

@@ -432,7 +432,7 @@ namespace Microsoft.Maui.Controls.Handlers
 			if (_mainLevelTabs == null)
 				return;
 
-			var currentItem = VirtualView.CurrentItem.CurrentItem;
+			var currentItem = VirtualView.CurrentItem?.CurrentItem;
 			NavigationViewItemViewModel? navigationViewItemViewModel = null;
 
 			foreach (var item in _mainLevelTabs)

src/Controls/src/Core/Shell/ShellItem.cs

@@ -284,7 +284,10 @@ namespace Microsoft.Maui.Controls
 			var shellItem = (ShellItem)bindable;
 
 			if (newValue == null)
+			{
+				shellItem.CurrentItem = null;
 				return;
+			}
 
 			if (shellItem.Parent is Shell)
 			{

src/Controls/tests/TestCases.HostApp/Issues/Issue8788.xaml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<Shell xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+        x:Class="Maui.Controls.Sample.Issues.Issue8788"
+        xmlns:local="clr-namespace:Maui.Controls.Sample.Issues"
+        Shell.FlyoutBehavior="Locked"
+        Shell.FlyoutWidth="200">
+
+  <MenuItem x:Name="MenuItem" Text="Click to hide Tab1" Clicked="MenuItem_Clicked" AutomationId="FirstButton" />
+
+  <TabBar>
+    <Tab x:Name="Tab1" AutomationId="Tab1" Title="Tab 1">
+      <ShellContent Title="Tab 1" ContentTemplate="{DataTemplate local:MainTabPage}" Route="MainPage" />
+    </Tab>
+
+    <Tab x:Name="Tab2" AutomationId="Tab2" Title="Tab 2" IsVisible="false">
+      <ShellContent Title="Tab 2" ContentTemplate="{DataTemplate local:SecondTabPage}" Route="Tab2Page" />
+    </Tab>
+
+    <Tab x:Name="Tab3" Title="Tab 3" AutomationId="Tab3" IsVisible="false">
+      <ShellContent Title="Tab 3"  ContentTemplate="{DataTemplate local:ThirdTabPage}" Route="Tab3Page" />
+    </Tab>
+  </TabBar>
+  
+</Shell>

src/Controls/tests/TestCases.HostApp/Issues/Issue8788.xaml.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	[Issue(IssueTracker.Github, 8788, "Shell Tab is still visible after set Tab.IsVisible to false", PlatformAffected.Android)]
+	public partial class Issue8788 : Shell
+	{
+		public Issue8788()
+		{
+			InitializeComponent();
+		}
+
+		private void MenuItem_Clicked(object sender, EventArgs e)
+		{
+#if ANDROID
+			Tab2.IsVisible = true;
+			Tab3.IsVisible = true;
+			Tab1.IsVisible = false;
+#else
+			Tab1.IsVisible = false;
+			Tab2.IsVisible = true;
+			Tab3.IsVisible = true;
+#endif
+		}
+	}
+
+	public partial class MainTabPage : ContentPage
+	{
+		public MainTabPage()
+		{
+			Content = new VerticalStackLayout()
+			{
+				new Label(){
+					Text = "Page Loaded in first Tab",
+					VerticalOptions = LayoutOptions.Center,
+					HorizontalOptions = LayoutOptions.Center,
+					TextDecorations = TextDecorations.Underline,
+
+				},
+			};
+		}
+	}
+
+	public partial class SecondTabPage : ContentPage
+	{
+		public SecondTabPage()
+		{
+			Content = new VerticalStackLayout()
+			{
+				new Label(){
+						Text = "Page Loaded in Second Tab",
+						VerticalOptions = LayoutOptions.Center,
+						HorizontalOptions = LayoutOptions.Center,
+						TextDecorations = TextDecorations.Underline,
+
+					},
+			};
+		}
+	}
+	public partial class ThirdTabPage : ContentPage
+	{
+		public ThirdTabPage()
+		{
+			Content = new VerticalStackLayout()
+			{
+				new Label(){
+						Text = "Page Loaded in Third Tab",
+						VerticalOptions = LayoutOptions.Center,
+						HorizontalOptions = LayoutOptions.Center,
+						TextDecorations = TextDecorations.Underline,
+
+					},
+			};
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue8788.cs

@@ -0,0 +1,28 @@
+#if !MACCATALYST
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	internal class Issue8788 : _IssuesUITest
+	{
+		public Issue8788(TestDevice device) : base(device) { }
+
+		public override string Issue => "Shell Tab is still visible after set Tab.IsVisible to false";
+
+		[Test]
+		[Category(UITestCategories.Shell)]
+		public void ShellTabItemsShouldUpdateForDynamicChangesInVisibility()
+		{
+#if WINDOWS
+			App.TapCoordinates(100, 57);
+#else
+			App.WaitForElement("FirstButton");
+			App.Tap("FirstButton");
+#endif
+			VerifyScreenshot();
+		}
+	}
+}
+#endif