The footer position is not on the far right of the horizontal grid - fix (#28864)

* Update StructuredItemsViewController.cs

* Add UI test

---------

Co-authored-by: Alberto Aldegheri <albyrock87@gmail.com>

Author: kubaflo

src/Controls/src/Core/Handlers/Items/iOS/StructuredItemsViewController.cs

@@ -161,7 +161,7 @@ void UpdateHeaderFooterPosition()
 
 				if (_footerUIView != null && IsViewLoaded && View.Window != null)
 				{
-					var width = ItemsViewLayout.CollectionViewContentSize.Height;
+					var width = ItemsViewLayout.CollectionViewContentSize.Width;
 					var footerX = width + emptyWidth;
 					var currentFrame = _footerUIView.Frame;
 

src/Controls/tests/TestCases.HostApp/Elements/CollectionView/HeaderFooterGalleries/HeaderFooterGallery.cs

@@ -20,6 +20,7 @@ public HeaderFooterGallery()
 						descriptionLabel,
 						TestBuilder.NavButton("Header/Footer (String)", () => new HeaderFooterString(), Navigation),
 						TestBuilder.NavButton("Header/Footer (Forms View)", () => new HeaderFooterView(), Navigation),
+						TestBuilder.NavButton("Header/Footer (Horizontal Forms View)", () => new HeaderFooterViewHorizontal(), Navigation),
 						TestBuilder.NavButton("Header/Footer (Template)", () => new HeaderFooterTemplate(), Navigation),
 						TestBuilder.NavButton("Header/Footer (Grid)", () => new HeaderFooterGrid(), Navigation),
 						TestBuilder.NavButton("Footer Only (String)", () => new FooterOnlyString(), Navigation),

src/Controls/tests/TestCases.HostApp/Elements/CollectionView/HeaderFooterGalleries/HeaderFooterViewHorizontal.xaml

@@ -0,0 +1,43 @@
+<?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"
+             xmlns:d="http://schemas.microsoft.com/dotnet/2021/maui/design"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             mc:Ignorable="d"
+             x:Class=" Maui.Controls.Sample.CollectionViewGalleries.HeaderFooterGalleries.HeaderFooterViewHorizontal">
+    <ContentPage.Content>
+        <Grid ColumnDefinitions="*,*" RowDefinitions="Auto,*">
+          <Button Text="Add 2 Items" Grid.Row="0" Grid.Column="0" HorizontalOptions="Center"
+                  Command="{Binding AddCommand}" />
+          <Button Text="Clear All Items" Grid.Row="0" Grid.Column="1" HorizontalOptions="Center"
+                  Command="{Binding ClearCommand}" />
+          
+          <CollectionView Grid.Row="1" Grid.ColumnSpan="2" x:Name="CollectionView" AutomationId="CV" ItemsSource="{Binding Items}">
+              <CollectionView.ItemsLayout>
+                <LinearItemsLayout Orientation="Horizontal" />
+              </CollectionView.ItemsLayout>
+            
+              <CollectionView.Header>
+                <Grid WidthRequest="160">
+                  <Image Source="oasis.jpg" Aspect="AspectFill"></Image>
+                  <Label Text="{Binding HeaderText}" TextColor="AntiqueWhite"
+                         VerticalOptions="Center" LineBreakMode="WordWrap" 
+                         HorizontalTextAlignment="Center" Rotation="10"
+                         FontAttributes="Bold" FontSize="20" />
+                </Grid>
+              </CollectionView.Header>
+
+              <CollectionView.Footer>
+                <Grid WidthRequest="160">
+                  <Image Source="cover1.jpg" Aspect="AspectFill"></Image>
+                  <Label Text="{Binding FooterText}" TextColor="AntiqueWhite"
+                         HorizontalTextAlignment="Center" Rotation="10"
+                         VerticalOptions="Center" LineBreakMode="WordWrap" 
+                         FontAttributes="Bold" FontSize="20" />
+                </Grid>
+              </CollectionView.Footer>
+
+          </CollectionView>
+        </Grid>
+    </ContentPage.Content>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Elements/CollectionView/HeaderFooterGalleries/HeaderFooterViewHorizontal.xaml.cs

@@ -0,0 +1,17 @@
+using System.Windows.Input;
+
+namespace Maui.Controls.Sample.CollectionViewGalleries.HeaderFooterGalleries
+{
+	public partial class HeaderFooterViewHorizontal : ContentPage
+	{
+		readonly HeaderFooterViewModel _viewModel = new HeaderFooterViewModel(10);
+
+		public HeaderFooterViewHorizontal()
+		{
+			InitializeComponent();
+
+			CollectionView.ItemTemplate = ExampleTemplates.PhotoTemplate();
+			BindingContext = _viewModel;
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/CollectionView/CollectionViewUITests.HeaderAndFooter.cs

@@ -43,6 +43,29 @@ public void HeaderFooterViewWorks()
             App.WaitForElement("This Is A Footer");
         }
 
+		[Test]
+		[Category(UITestCategories.CollectionView)]
+		public void HeaderFooterHorizontalViewWorks()
+		{
+			// Navigate to the selection galleries
+			VisitInitialGallery("Header Footer");
+
+			// Navigate to the specific sample inside selection galleries
+			VisitSubGallery("Header/Footer (Horizontal Forms View)");
+
+			// Verify the header is visible
+			App.WaitForElement("This Is A Header");
+			
+			// Scroll right to ensure the footer is visible and positioned at the end
+			for (int i = 0; i < 5; i++)
+			{
+				App.ScrollRight("CV", ScrollStrategy.Auto, 0.9, 250);
+			}
+
+			// Verify the footer is visible
+			App.WaitForElement("This Is A Footer");
+		}
+
         [Test]
         [Category(UITestCategories.CollectionView)]
         public void HeaderFooterTemplateWorks()