[net9.0][Enhancement] FontImageSource defaults and style (#23602)

* FontImageSource defaults and style

* Added tests

* Added snapshots

src/Controls/src/Core/ImageSource.cs

@@ -18,8 +18,11 @@ public abstract partial class ImageSource : Element
 
 		readonly WeakEventManager _weakEventManager = new WeakEventManager();
 
+		internal readonly MergedStyle _mergedStyle;
+
 		protected ImageSource()
 		{
+			_mergedStyle = new MergedStyle(GetType(), this);
 		}
 
 		/// <include file="../../docs/Microsoft.Maui.Controls/ImageSource.xml" path="//Member[@MemberName='IsEmpty']/Docs/*" />

src/Controls/tests/TestCases.HostApp/Issues/Issue13474.xaml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Maui.Controls.Sample.Issues.Issue13474">
+    <ContentPage.Resources>
+        <Style TargetType="FontImageSource">
+            <Setter Property="FontFamily" Value="FontAwesome"/>
+            <Setter Property="Color" Value="Red"/>
+        </Style>
+    </ContentPage.Resources>
+
+    <VerticalStackLayout>
+        <ImageButton 
+            HeightRequest="100"
+            WidthRequest="100" 
+            BackgroundColor="Green" 
+            AutomationId="imageButton"
+            Source="{FontImageSource Glyph=''}"/>
+    </VerticalStackLayout>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue13474.xaml.cs

@@ -0,0 +1,11 @@
+namespace Maui.Controls.Sample.Issues;
+
+[XamlCompilation(XamlCompilationOptions.Compile)]
+[Issue(IssueTracker.Github, 13474, "FontImageSource defaults and style", PlatformAffected.All)]
+public partial class Issue13474 : ContentPage
+{
+	public Issue13474()
+	{
+		InitializeComponent();
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue13474.cs

@@ -0,0 +1,23 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue13474 : _IssuesUITest
+	{
+		public Issue13474(TestDevice device) : base(device) { }
+
+		public override string Issue => "FontImageSource defaults and style";
+
+		[Test]
+		[Category(UITestCategories.ImageButton)]
+		public void Issue13474Test()
+		{
+			App.WaitForElement("imageButton");
+
+			// The test passes if font family and color is applied
+			VerifyScreenshot();
+		}
+	}
+}

src/Controls/tests/Xaml.UnitTests/Issues/Maui13474.xaml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+                    x:Class="Microsoft.Maui.Controls.Xaml.UnitTests.Maui13474">
+    <ContentPage.Resources>
+        <Style TargetType="FontImageSource">
+            <Setter Property="FontFamily" Value="FontAwesome"/>
+            <Setter Property="Color" Value="Red"/>
+        </Style>
+    </ContentPage.Resources>
+
+    <VerticalStackLayout>
+        <ImageButton 
+            x:Name="imageButton"
+            HeightRequest="100"
+            WidthRequest="100" 
+            BackgroundColor="Green" 
+            AutomationId="imageButton"
+            Source="{FontImageSource Glyph=''}"/>
+    </VerticalStackLayout>
+</ContentPage>

src/Controls/tests/Xaml.UnitTests/Issues/Maui13474.xaml.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Globalization;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.Maui.ApplicationModel;
+using Microsoft.Maui.Controls.Core.UnitTests;
+using Microsoft.Maui.Controls.Shapes;
+using Microsoft.Maui.Devices;
+using Microsoft.Maui.Dispatching;
+
+using Microsoft.Maui.Graphics;
+using Microsoft.Maui.UnitTests;
+using NUnit.Framework;
+
+namespace Microsoft.Maui.Controls.Xaml.UnitTests;
+
+public partial class Maui13474
+{
+    public Maui13474()
+    {
+        InitializeComponent();
+    }
+
+    public Maui13474(bool useCompiledXaml)
+    {
+        //this stub will be replaced at compile time
+    }
+
+    [TestFixture]
+    class Test
+    {
+        [SetUp]
+        public void Setup()
+        {
+            Application.SetCurrentApplication(new MockApplication());
+            DispatcherProvider.SetCurrent(new DispatcherProviderStub());
+        }
+
+        [TearDown] public void TearDown() => AppInfo.SetCurrent(null);
+
+        [Test]
+        public void FontImageSourceIsAppliedFromSharedResources([Values(false, true)] bool useCompiledXaml)
+        {
+			var page = new Maui13474(useCompiledXaml);
+			var fontImageSource = page.imageButton.Source as FontImageSource;
+            Assert.AreEqual(fontImageSource.Color, Colors.Red);
+            Assert.AreEqual(fontImageSource.FontFamily, "FontAwesome");
+        }
+    }
+}