[.NET10] [Enhancement] Display Window Title in bold by default with configurable font attributes

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

@@ -30,6 +30,9 @@ Microsoft.Maui.Controls.ContentPage.SafeAreaEdges.get -> Microsoft.Maui.SafeArea
 Microsoft.Maui.Controls.ContentPage.SafeAreaEdges.set -> void
 Microsoft.Maui.Controls.ContentPresenter.CascadeInputTransparent.get -> bool
 Microsoft.Maui.Controls.ContentPresenter.CascadeInputTransparent.set -> void
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.get -> Microsoft.Maui.Controls.FontAttributes
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.set -> void
+static readonly Microsoft.Maui.Controls.TitleBar.TitleFontAttributesProperty -> Microsoft.Maui.Controls.BindableProperty!
 ~Microsoft.Maui.Controls.ContentPresenter.Children.get -> System.Collections.Generic.IReadOnlyList<Microsoft.Maui.Controls.Element>
 ~Microsoft.Maui.Controls.ContentPresenter.LowerChild(Microsoft.Maui.Controls.View view) -> void
 Microsoft.Maui.Controls.ContentPresenter.Padding.get -> Microsoft.Maui.Thickness

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

@@ -37,6 +37,9 @@ Microsoft.Maui.Controls.ContentPresenter.CascadeInputTransparent.set -> void
 ~Microsoft.Maui.Controls.ContentPresenter.LowerChild(Microsoft.Maui.Controls.View view) -> void
 Microsoft.Maui.Controls.ContentPresenter.Padding.get -> Microsoft.Maui.Thickness
 Microsoft.Maui.Controls.ContentPresenter.Padding.set -> void
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.get -> Microsoft.Maui.Controls.FontAttributes
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.set -> void
+static readonly Microsoft.Maui.Controls.TitleBar.TitleFontAttributesProperty -> Microsoft.Maui.Controls.BindableProperty!
 ~Microsoft.Maui.Controls.ContentPresenter.RaiseChild(Microsoft.Maui.Controls.View view) -> void
 Microsoft.Maui.Controls.ContentPresenter.UpdateChildrenLayout() -> void
 Microsoft.Maui.Controls.ContentView.SafeAreaEdges.get -> Microsoft.Maui.SafeAreaEdges

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

@@ -33,6 +33,9 @@ Microsoft.Maui.Controls.ContentPage.SafeAreaEdges.get -> Microsoft.Maui.SafeArea
 Microsoft.Maui.Controls.ContentPage.SafeAreaEdges.set -> void
 Microsoft.Maui.Controls.ContentPresenter.CascadeInputTransparent.get -> bool
 Microsoft.Maui.Controls.ContentPresenter.CascadeInputTransparent.set -> void
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.get -> Microsoft.Maui.Controls.FontAttributes
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.set -> void
+static readonly Microsoft.Maui.Controls.TitleBar.TitleFontAttributesProperty -> Microsoft.Maui.Controls.BindableProperty!
 ~Microsoft.Maui.Controls.ContentPresenter.Children.get -> System.Collections.Generic.IReadOnlyList<Microsoft.Maui.Controls.Element>
 ~Microsoft.Maui.Controls.ContentPresenter.LowerChild(Microsoft.Maui.Controls.View view) -> void
 Microsoft.Maui.Controls.ContentPresenter.Padding.get -> Microsoft.Maui.Thickness

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

@@ -34,6 +34,9 @@ Microsoft.Maui.Controls.ILineHeightElement.OnLineHeightChanged(double oldValue,
 *REMOVED*Microsoft.Maui.Controls.IMessagingCenter
 Microsoft.Maui.Controls.SearchHandler.HideSoftInputAsync() -> void
 Microsoft.Maui.Controls.SearchHandler.ShowSoftInputAsync() -> void
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.get -> Microsoft.Maui.Controls.FontAttributes
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.set -> void
+static readonly Microsoft.Maui.Controls.TitleBar.TitleFontAttributesProperty -> Microsoft.Maui.Controls.BindableProperty!
 *REMOVED*~Microsoft.Maui.Controls.IMessagingCenter.Send<TSender, TArgs>(TSender sender, string message, TArgs args) -> void
 *REMOVED*~Microsoft.Maui.Controls.IMessagingCenter.Send<TSender>(TSender sender, string message) -> void
 *REMOVED*~Microsoft.Maui.Controls.IMessagingCenter.Subscribe<TSender, TArgs>(object subscriber, string message, System.Action<TSender, TArgs> callback, TSender source = null) -> void

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

@@ -30,6 +30,9 @@ Microsoft.Maui.Controls.ContentPage.SafeAreaEdges.get -> Microsoft.Maui.SafeArea
 Microsoft.Maui.Controls.ContentPage.SafeAreaEdges.set -> void
 Microsoft.Maui.Controls.ContentPresenter.CascadeInputTransparent.get -> bool
 Microsoft.Maui.Controls.ContentPresenter.CascadeInputTransparent.set -> void
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.get -> Microsoft.Maui.Controls.FontAttributes
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.set -> void
+static readonly Microsoft.Maui.Controls.TitleBar.TitleFontAttributesProperty -> Microsoft.Maui.Controls.BindableProperty!
 ~Microsoft.Maui.Controls.ContentPresenter.Children.get -> System.Collections.Generic.IReadOnlyList<Microsoft.Maui.Controls.Element>
 ~Microsoft.Maui.Controls.ContentPresenter.LowerChild(Microsoft.Maui.Controls.View view) -> void
 Microsoft.Maui.Controls.ContentPresenter.Padding.get -> Microsoft.Maui.Thickness

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

@@ -30,6 +30,9 @@ Microsoft.Maui.Controls.ContentPage.SafeAreaEdges.get -> Microsoft.Maui.SafeArea
 Microsoft.Maui.Controls.ContentPage.SafeAreaEdges.set -> void
 Microsoft.Maui.Controls.ContentPresenter.CascadeInputTransparent.get -> bool
 Microsoft.Maui.Controls.ContentPresenter.CascadeInputTransparent.set -> void
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.get -> Microsoft.Maui.Controls.FontAttributes
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.set -> void
+static readonly Microsoft.Maui.Controls.TitleBar.TitleFontAttributesProperty -> Microsoft.Maui.Controls.BindableProperty!
 ~Microsoft.Maui.Controls.ContentPresenter.Children.get -> System.Collections.Generic.IReadOnlyList<Microsoft.Maui.Controls.Element>
 ~Microsoft.Maui.Controls.ContentPresenter.LowerChild(Microsoft.Maui.Controls.View view) -> void
 Microsoft.Maui.Controls.ContentPresenter.Padding.get -> Microsoft.Maui.Thickness

src/Controls/src/Core/PublicAPI/netstandard/PublicAPI.Unshipped.txt

@@ -30,6 +30,9 @@ Microsoft.Maui.Controls.ContentPage.SafeAreaEdges.get -> Microsoft.Maui.SafeArea
 Microsoft.Maui.Controls.ContentPage.SafeAreaEdges.set -> void
 Microsoft.Maui.Controls.ContentPresenter.CascadeInputTransparent.get -> bool
 Microsoft.Maui.Controls.ContentPresenter.CascadeInputTransparent.set -> void
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.get -> Microsoft.Maui.Controls.FontAttributes
+Microsoft.Maui.Controls.TitleBar.TitleFontAttributes.set -> void
+static readonly Microsoft.Maui.Controls.TitleBar.TitleFontAttributesProperty -> Microsoft.Maui.Controls.BindableProperty!
 override Microsoft.Maui.Controls.CheckBox.IsEnabledCore.get -> bool
 ~Microsoft.Maui.Controls.CheckBox.Command.get -> System.Windows.Input.ICommand
 ~Microsoft.Maui.Controls.CheckBox.Command.set -> void

src/Controls/src/Core/TitleBar/TitleBar.cs

@@ -71,84 +71,89 @@ public partial class TitleBar : TemplatedView, ITitleBar, ISafeAreaView
 		public static readonly BindableProperty ForegroundColorProperty = BindableProperty.Create(nameof(ForegroundColor),
 			typeof(Color), typeof(TitleBar));
 
+		/// <summary>Bindable property for <see cref="TitleFontAttributes"/>.</summary>
+		public static readonly BindableProperty TitleFontAttributesProperty =
+			BindableProperty.Create(nameof(TitleFontAttributes), typeof(FontAttributes),
+				typeof(TitleBar), FontAttributes.None);
+
 		static void OnLeadingChanged(BindableObject bindable, object oldValue, object newValue)
 		{
-			var titlebar = (TitleBar)bindable;
+			var titleBar = (TitleBar)bindable;
 			if (newValue is null)
 			{
-				titlebar.ApplyVisibleState(LeadingHiddenState);
+				titleBar.ApplyVisibleState(LeadingHiddenState);
 			}
 			else
 			{
-				titlebar.ApplyVisibleState(LeadingVisibleState);
+				titleBar.ApplyVisibleState(LeadingVisibleState);
 				(newValue as Layout)?.IgnoreLayoutSafeArea();
 			}
 		}
 
 		static void OnIconChanged(BindableObject bindable, object oldValue, object newValue)
 		{
-			var titlebar = (TitleBar)bindable;
+			var titleBar = (TitleBar)bindable;
 			var imageSource = newValue as ImageSource;
 			if (imageSource is null || imageSource.IsEmpty)
 			{
-				titlebar.ApplyVisibleState(IconHiddenState);
+				titleBar.ApplyVisibleState(IconHiddenState);
 			}
 			else
 			{
-				titlebar.ApplyVisibleState(IconVisibleState);
+				titleBar.ApplyVisibleState(IconVisibleState);
 			}
 		}
 
 		static void OnTitleChanged(BindableObject bindable, object oldValue, object newValue)
 		{
-			var titlebar = (TitleBar)bindable;
+			var titleBar = (TitleBar)bindable;
 			if (newValue is null)
 			{
-				titlebar.ApplyVisibleState(TitleHiddenState);
+				titleBar.ApplyVisibleState(TitleHiddenState);
 			}
 			else
 			{
-				titlebar.ApplyVisibleState(TitleVisibleState);
+				titleBar.ApplyVisibleState(TitleVisibleState);
 			}
 		}
 
 		static void OnSubtitleChanged(BindableObject bindable, object oldValue, object newValue)
 		{
-			var titlebar = (TitleBar)bindable;
+			var titleBar = (TitleBar)bindable;
 			if (newValue is null)
 			{
-				titlebar.ApplyVisibleState(SubtitleHiddenState);
+				titleBar.ApplyVisibleState(SubtitleHiddenState);
 			}
 			else
 			{
-				titlebar.ApplyVisibleState(SubtitleVisibleState);
+				titleBar.ApplyVisibleState(SubtitleVisibleState);
 			}
 		}
 
 		static void OnContentChanged(BindableObject bindable, object oldValue, object newValue)
 		{
-			var titlebar = (TitleBar)bindable;
+			var titleBar = (TitleBar)bindable;
 			if (newValue is null)
 			{
-				titlebar.ApplyVisibleState(ContentHiddenState);
+				titleBar.ApplyVisibleState(ContentHiddenState);
 			}
 			else
 			{
-				titlebar.ApplyVisibleState(ContentVisibleState);
+				titleBar.ApplyVisibleState(ContentVisibleState);
 				(newValue as Layout)?.IgnoreLayoutSafeArea();
 			}
 		}
 
 		static void OnTrailingContentChanged(BindableObject bindable, object oldValue, object newValue)
 		{
-			var titlebar = (TitleBar)bindable;
+			var titleBar = (TitleBar)bindable;
 			if (newValue is null)
 			{
-				titlebar.ApplyVisibleState(TrailingHiddenState);
+				titleBar.ApplyVisibleState(TrailingHiddenState);
 			}
 			else
 			{
-				titlebar.ApplyVisibleState(TrailingVisibleState);
+				titleBar.ApplyVisibleState(TrailingVisibleState);
 				(newValue as Layout)?.IgnoreLayoutSafeArea();
 			}
 		}
@@ -236,6 +241,16 @@ public Color ForegroundColor
 			set { SetValue(ForegroundColorProperty, value); }
 		}
 
+		/// <summary>
+		/// Gets or sets the <see cref="FontAttributes"/> applied to the title text.
+		/// Defaults to <see cref="FontAttributes.None"/>.
+		/// </summary>
+		public FontAttributes TitleFontAttributes
+		{
+			get => (FontAttributes)GetValue(TitleFontAttributesProperty);
+			set => SetValue(TitleFontAttributesProperty, value);
+		}
+
 		/// <inheritdoc/>
 		public IList<IView> PassthroughElements { get; private set; }
 
@@ -451,6 +466,11 @@ static View BuildDefaultTemplate()
 				static (TitleBar tb) => tb.ForegroundColor,
 				source: RelativeBindingSource.TemplatedParent);
 
+			titleLabel.SetBinding(
+				Label.FontAttributesProperty,
+				static (TitleBar tb) => tb.TitleFontAttributes,
+				source: RelativeBindingSource.TemplatedParent);
+
 			var activeVisualState = new VisualState() { Name = TitleBarActiveState };
 			activeVisualState.Setters.Add(
 				new Setter()

src/Controls/tests/TestCases.HostApp/Issues/Issue24627.cs

@@ -0,0 +1,77 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 24627, "[Windows] TitleBar Title FontAttributes", PlatformAffected.UWP)]
+public class Issue24627 : ContentPage
+{
+	TitleBar customTitleBar;
+
+	public Issue24627()
+	{
+		customTitleBar = new TitleBar
+		{
+			Title = "MauiApp1",
+			Subtitle = "Welcome to .NET MAUI",
+			TitleFontAttributes = FontAttributes.Bold,
+			HeightRequest = 32
+		};
+
+		var label = new Label
+		{
+			Text = "Welcome to .NET MAUI",
+			HorizontalOptions = LayoutOptions.Center,
+			VerticalOptions = LayoutOptions.Center,
+		};
+
+		var button = new Button
+		{
+			Text = "Set Title FontAttributes to None",
+			AutomationId = "ChangeFAButton",
+			Command = new Command(() =>
+			{
+				customTitleBar.TitleFontAttributes = FontAttributes.None;
+			}),
+			HorizontalOptions = LayoutOptions.Center,
+			VerticalOptions = LayoutOptions.Center
+		};
+
+		var italicButton = new Button
+		{
+			Text = "Set Title FontAttributes to Italic",
+			AutomationId = "ItalicButton",
+			Command = new Command(() =>
+			{
+				customTitleBar.TitleFontAttributes = FontAttributes.Italic;
+			}),
+			HorizontalOptions = LayoutOptions.Center,
+			VerticalOptions = LayoutOptions.Center
+		};
+
+		var verticalStack = new VerticalStackLayout
+		{
+			Children =
+			{
+				label,
+				button,
+				italicButton
+			},
+			Spacing = 25,
+			Padding = new Thickness(30, 0),
+			VerticalOptions = LayoutOptions.Center
+		};
+
+		Content = verticalStack;
+	}
+
+	protected override void OnAppearing()
+	{
+		base.OnAppearing();
+		if (Window is not null)
+		{
+			Window.TitleBar = customTitleBar;
+		}
+		else if (Shell.Current?.Window is not null)
+		{
+			Shell.Current.Window.TitleBar = customTitleBar;
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue24627.cs

@@ -0,0 +1,42 @@
+#if WINDOWS || MACCATALYST // TitleBar is only supported on Windows and MacCatalyst
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue24627 : _IssuesUITest
+{
+	public override string Issue => "[Windows] TitleBar Title FontAttributes";
+
+	public Issue24627(TestDevice device)
+	: base(device)
+	{ }
+
+	[Test, Order(1)]
+	[Category(UITestCategories.TitleView)]
+	public void VerifyTitleBarTitleFontAttributesBold()
+	{
+		App.WaitForElement("ChangeFAButton");
+		VerifyScreenshot(includeTitleBar: true);
+	}
+
+	[Test, Order(2)]
+	[Category(UITestCategories.TitleView)]
+	public void ChangeTitleBarTitleFontAttributesToNone()
+	{
+		App.WaitForElement("ChangeFAButton");
+		App.Tap("ChangeFAButton");
+		VerifyScreenshot(includeTitleBar: true);
+	}
+
+	[Test, Order(3)]
+	[Category(UITestCategories.TitleView)]
+	public void ChangeTitleBarTitleFontAttributesToItalic()
+	{
+		App.WaitForElement("ItalicButton");
+		App.Tap("ItalicButton");
+		VerifyScreenshot(includeTitleBar: true);
+	}
+}
+#endif