Fix ShellContent Title doesn't observe changes to bound properties (#…

…24806)

* fix added

* UI test added

* platform affected codes updated

* script file changes updated

* review changes updated

* Test case file changes updated

* tabbar automation id casing updated

* Automation ID changed for button

* unshipped file changes reverted

* changes updated

* platform condition updated

* UI test modified

* screen shot added

* access specifier changed

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

@@ -149,6 +149,30 @@ public override AView OnCreateView(LayoutInflater inflater, ViewGroup container,
 			return _rootView = root;
 		}
 
+		void OnShellContentPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
+		{
+			if (e.PropertyName == ShellContent.TitleProperty.PropertyName && sender is ShellContent shellContent)
+			{
+				UpdateTabTitle(shellContent);
+			}
+		}
+
+		void UpdateTabTitle(ShellContent shellContent)
+		{
+			if (_tablayout == null || SectionController.GetItems().Count == 0)
+				return;
+
+			int index = SectionController.GetItems().IndexOf(shellContent);
+			if (index >= 0)
+			{
+				var tab = _tablayout.GetTabAt(index);
+				if (tab != null)
+				{
+					tab.SetText(new string(shellContent.Title));
+				}
+			}
+		}
+
 		void OnTabLayoutChange(object sender, AView.LayoutChangeEventArgs e)
 		{
 			if (_disposed)
@@ -327,13 +351,21 @@ void HookEvents()
 			SectionController.ItemsCollectionChanged += OnItemsCollectionChanged;
 			((IShellController)_shellContext.Shell).AddAppearanceObserver(this, ShellSection);
 			ShellSection.PropertyChanged += OnShellItemPropertyChanged;
+			foreach (var item in SectionController.GetItems())
+			{
+				item.PropertyChanged += OnShellContentPropertyChanged;
+			}
 		}
 
 		void UnhookEvents()
 		{
 			SectionController.ItemsCollectionChanged -= OnItemsCollectionChanged;
 			((IShellController)_shellContext?.Shell)?.RemoveAppearanceObserver(this);
 			ShellSection.PropertyChanged -= OnShellItemPropertyChanged;
+			foreach (var item in SectionController.GetItems())
+			{
+				item.PropertyChanged -= OnShellContentPropertyChanged;
+			}
 		}
 
 		protected virtual void OnPageSelected(int position)

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

@@ -7,7 +7,7 @@ namespace Microsoft.Maui.Controls.Handlers
 	public partial class ShellContentHandler : ElementHandler<ShellContent, FrameworkElement>
 	{
 		public static PropertyMapper<ShellContent, ShellContentHandler> Mapper =
-				new PropertyMapper<ShellContent, ShellContentHandler>(ElementMapper);
+				new PropertyMapper<ShellContent, ShellContentHandler>(ElementMapper) { [nameof(ShellContent.Title)] = MapTitle };
 
 		public static CommandMapper<ShellContent, ShellContentHandler> CommandMapper =
 				new CommandMapper<ShellContent, ShellContentHandler>(ElementCommandMapper);
@@ -16,6 +16,14 @@ public ShellContentHandler() : base(Mapper, CommandMapper)
 		{
 		}
 
+		internal static void MapTitle(ShellContentHandler handler, ShellContent item)
+		{
+			var shellSection = item.Parent as ShellSection;
+			var shellItem = shellSection?.Parent as ShellItem;
+			var shellItemHandler = shellItem?.Handler as ShellItemHandler;
+			shellItemHandler?.UpdateTitle();
+		}
+
 		protected override FrameworkElement CreatePlatformElement()
 		{
 			return (VirtualView as IShellContentController).GetOrCreateContent().ToPlatform(MauiContext);

src/Controls/src/Core/PublicAPI/net-windows/PublicAPI.Unshipped.txt

@@ -1 +1 @@
-#nullable enable
+#nullable enable

src/Controls/src/Core/Shell/BaseShellItem.cs

@@ -51,7 +51,7 @@ public class BaseShellItem : NavigableElement, IPropertyPropagationController, I
 
 		/// <summary>Bindable property for <see cref="Title"/>.</summary>
 		public static readonly BindableProperty TitleProperty =
-			BindableProperty.Create(nameof(Title), typeof(string), typeof(BaseShellItem), null, BindingMode.OneTime, propertyChanged: OnTitlePropertyChanged);
+			BindableProperty.Create(nameof(Title), typeof(string), typeof(BaseShellItem), null, BindingMode.TwoWay, propertyChanged: OnTitlePropertyChanged);
 
 		/// <summary>Bindable property for <see cref="IsVisible"/>.</summary>
 		public static readonly BindableProperty IsVisibleProperty =

src/Controls/tests/TestCases.HostApp/Issues/Issue7453.xaml

@@ -0,0 +1,29 @@
+<?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.Issue7453"
+             FlyoutBehavior="Disabled"
+             Title="Issue7453">
+    <TabBar AutomationId="TabBar">
+        <Tab Title="Nested Tabs" AutomationId="tabbar">
+            <ShellContent x:Name="tab" Title="Home">
+                <ContentPage>
+                    <StackLayout HorizontalOptions="Center" Spacing="30">
+                        <HorizontalStackLayout>
+                            <Label Text="Current Shell Title : " FontAttributes="Bold"/>
+                            <Label Text="{Binding Source={x:Reference tab}, Path=Title}" AutomationId="LabelId" />
+                        </HorizontalStackLayout>
+                        <Button Text="Change Title" AutomationId="ChangeShellContentTitle" VerticalOptions="Center" HorizontalOptions="Center" WidthRequest="100" HeightRequest="40" Clicked="OnButtonClicked"/>
+                    </StackLayout>
+                </ContentPage>
+            </ShellContent>
+
+            <ShellContent Title="Settings">
+                <ContentPage>
+                    <Label Text="This is Settings page"/>
+                </ContentPage>
+            </ShellContent>
+        </Tab>
+    </TabBar>
+
+</Shell>

src/Controls/tests/TestCases.HostApp/Issues/Issue7453.xaml.cs

@@ -0,0 +1,16 @@
+namespace Maui.Controls.Sample.Issues;
+
+[XamlCompilation(XamlCompilationOptions.Compile)]
+[Issue(IssueTracker.Github, 7453, "ShellContent Title doesn't observe changes to bound properties", PlatformAffected.UWP | PlatformAffected.Android)]
+public partial class Issue7453 : Shell
+{
+	public Issue7453()
+	{
+		InitializeComponent();
+	}
+
+    private void OnButtonClicked(object sender, EventArgs e)
+    {
+		this.tab.Title = "Updated title";
+    }
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue7453.cs

@@ -0,0 +1,32 @@
+#if !MACCATALYST
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.Maui.Controls;
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue7453 : _IssuesUITest
+	{
+		public Issue7453(TestDevice device) : base(device)
+		{
+		}
+
+		public override string Issue => "ShellContent Title doesn't observe changes to bound properties";
+
+		[Test]
+		[Category(UITestCategories.Shell)]
+		public void ChangeShellContentTitle()
+		{
+			App.WaitForElement("ChangeShellContentTitle");
+			App.Click("ChangeShellContentTitle");
+			VerifyScreenshot();
+		}
+	}
+}
+#endif