[iOS] Frames' content update (dotnet#20501)

* [iOS] Fixed updating frame's content (dotnet#19127)

* Added a UiTest (dotnet#19127)

* Code refactor

---------

Co-authored-by: Javier Suárez <[email protected]>

src/Controls/samples/Controls.Sample.UITests/Issues/Issue19127.xaml

@@ -0,0 +1,32 @@
+<?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.Issue19127"
+             xmlns:ns="clr-namespace:Maui.Controls.Sample.Issues">
+         <VerticalStackLayout
+            VerticalOptions="Center">
+            <Button Text="{Binding IsCameraEnabled, StringFormat='Toggle Camera View ({0})'}"
+                    Command="{Binding EnableCamera}"
+                    AutomationId="button" />
+
+            <Frame x:Name="frame"
+                   HeightRequest="191">
+                <Frame.Triggers>
+                    <DataTrigger TargetType="Frame" Binding="{Binding IsCameraEnabled}" Value="False">
+                        <Setter Property="Content">
+                            <Grid BackgroundColor="Gray">
+                                <Label AutomationId="label1" Text="Camera is Disabled" TextColor="White" />
+                            </Grid>
+                        </Setter>
+                    </DataTrigger>
+                    <DataTrigger TargetType="Frame" Binding="{Binding IsCameraEnabled}" Value="True">
+                        <Setter Property="Content">
+                            <Grid BackgroundColor="HotPink">
+                                <Label AutomationId="label2" Text="Camera is Enabled" TextColor="White" />
+                            </Grid>
+                        </Setter>
+                    </DataTrigger>
+                </Frame.Triggers>
+            </Frame>
+        </VerticalStackLayout>
+</ContentPage>

src/Controls/samples/Controls.Sample.UITests/Issues/Issue19127.xaml.cs

@@ -0,0 +1,47 @@
+using System;
+using System.ComponentModel;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	[Issue(IssueTracker.Github, 19127, "Triggers are not working on Frame control", PlatformAffected.iOS)]
+	public partial class Issue19127 : ContentPage
+	{
+		public Issue19127()
+		{
+			InitializeComponent();
+			BindingContext = new Issue19127Settings();
+		}
+	}
+
+	public class Issue19127Settings : INotifyPropertyChanged
+	{
+		public event PropertyChangedEventHandler PropertyChanged;
+
+		public Command EnableCamera { get; set; }
+
+		private bool _isCameraEnabled;
+		public bool IsCameraEnabled
+		{
+			get { return _isCameraEnabled; }
+			set
+			{
+				_isCameraEnabled = value;
+				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(IsCameraEnabled)));
+			}
+		}
+
+		public Issue19127Settings()
+		{
+			IsCameraEnabled = false;
+			EnableCamera = new Command(() => ToggleEnableCamera());
+		}
+
+		private void ToggleEnableCamera()
+		{
+			IsCameraEnabled = !_isCameraEnabled;
+		}
+	}
+}

src/Controls/src/Core/Compatibility/Handlers/iOS/FrameRenderer.cs

@@ -11,7 +11,17 @@ namespace Microsoft.Maui.Controls.Handlers.Compatibility
 	public class FrameRenderer : VisualElementRenderer<Frame>
 	{
 		public static IPropertyMapper<Frame, FrameRenderer> Mapper
-			= new PropertyMapper<Frame, FrameRenderer>(VisualElementRendererMapper);
+			= new PropertyMapper<Frame, FrameRenderer>(VisualElementRendererMapper)
+			{
+				[VisualElement.BackgroundColorProperty.PropertyName] = (h, _) => h.SetupLayer(),
+				[VisualElement.BackgroundProperty.PropertyName] = (h, _) => h.SetupLayer(),
+				[Microsoft.Maui.Controls.Frame.BorderColorProperty.PropertyName] = (h, _) => h.SetupLayer(),
+				[Microsoft.Maui.Controls.Frame.CornerRadiusProperty.PropertyName] = (h, _) => h.SetupLayer(),
+				[Microsoft.Maui.Controls.Frame.IsClippedToBoundsProperty.PropertyName] = (h, _) => h.SetupLayer(),
+				[VisualElement.IsVisibleProperty.PropertyName] = (h, _) => h.SetupLayer(),
+				[Controls.Frame.HasShadowProperty.PropertyName] = (h, _) => h.UpdateShadow(),
+				[Microsoft.Maui.Controls.Frame.ContentProperty.PropertyName] = (h, _) => h.UpdateContent(),
+			};
 
 		public static CommandMapper<Frame, FrameRenderer> CommandMapper
 			= new CommandMapper<Frame, FrameRenderer>(VisualElementRendererCommandMapper);
@@ -60,16 +70,19 @@ protected override void OnElementChanged(ElementChangedEventArgs<Frame> e)
 		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
 			base.OnElementPropertyChanged(sender, e);
+		}
 
-			if (e.PropertyName == VisualElement.BackgroundColorProperty.PropertyName ||
-				e.PropertyName == VisualElement.BackgroundProperty.PropertyName ||
-				e.PropertyName == Microsoft.Maui.Controls.Frame.BorderColorProperty.PropertyName ||
-				e.PropertyName == Microsoft.Maui.Controls.Frame.CornerRadiusProperty.PropertyName ||
-				e.PropertyName == Microsoft.Maui.Controls.Frame.IsClippedToBoundsProperty.PropertyName ||
-				e.PropertyName == VisualElement.IsVisibleProperty.PropertyName)
-				SetupLayer();
-			else if (e.PropertyName == Controls.Frame.HasShadowProperty.PropertyName)
-				UpdateShadow();
+		void UpdateContent()
+		{
+			_actualView.ClearSubviews();
+
+			var content = Element?.Content;
+
+			if (content == null || MauiContext == null)
+				return;
+
+			var platformView = content.ToPlatform(MauiContext);
+			_actualView.AddSubview(platformView);
 		}
 
 		public override void TraitCollectionDidChange(UITraitCollection previousTraitCollection)

src/Controls/tests/UITests/Tests/Issues/Issue19127.cs

@@ -0,0 +1,30 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.AppiumTests.Issues
+{
+	public class Issue19127 : _IssuesUITest
+	{
+		public override string Issue => "Triggers are not working on Frame control";
+
+		public Issue19127(TestDevice device) : base(device)
+		{
+		}
+
+		[Test]
+		public void ContentOfFrameShouldChange()
+		{
+			_ = App.WaitForElement("button");
+
+			var textBeforeClick = App.FindElement("label1").GetText();
+
+			App.Click("button");
+
+			var textAfterClick = App.FindElement("label2").GetText();
+
+			Assert.AreEqual(textBeforeClick, "Camera is Disabled");
+			Assert.AreEqual(textAfterClick, "Camera is Enabled");
+		}
+	}
+}