[Android] Added a scroll bar for collection view (#25471)

Author: kubaflo

src/Controls/src/Core/Handlers/Items/Android/MauiRecyclerView.cs

@@ -4,6 +4,7 @@
 using System.ComponentModel;
 using System.Text;
 using Android.Content;
+using Android.Views;
 using AndroidX.RecyclerView.Widget;
 using Microsoft.Maui.Controls.Internals;
 using Microsoft.Maui.Controls.Platform;
@@ -47,16 +48,13 @@ public class MauiRecyclerView<TItemsView, TAdapter, TItemsViewSource> : Recycler
 
 		~MauiRecyclerView() => _layoutPropertyChangedProxy?.Unsubscribe();
 
-		public MauiRecyclerView(Context context, Func<IItemsLayout> getItemsLayout, Func<TAdapter> getAdapter) : base(context)
+		public MauiRecyclerView(Context context, Func<IItemsLayout> getItemsLayout, Func<TAdapter> getAdapter) : base(new ContextThemeWrapper(context, Resource.Style.collectionViewTheme))
 		{
 			_getItemsLayout = getItemsLayout ?? throw new ArgumentNullException(nameof(getItemsLayout));
 			CreateAdapter = getAdapter ?? throw new ArgumentNullException(nameof(getAdapter));
 
 			_emptyCollectionObserver = new DataChangeObserver(UpdateEmptyViewVisibility);
 			_itemsUpdateScrollObserver = new DataChangeObserver(AdjustScrollForItemUpdate);
-
-			VerticalScrollBarEnabled = false;
-			HorizontalScrollBarEnabled = false;
 		}
 
 		public virtual void TearDownOldElement(TItemsView oldElement)

src/Controls/src/Core/Handlers/Items/ItemsViewHandler.Android.cs

@@ -71,7 +71,7 @@ public static void MapHorizontalScrollBarVisibility(ItemsViewHandler<TItemsView>
 
 		public static void MapVerticalScrollBarVisibility(ItemsViewHandler<TItemsView> handler, ItemsView itemsView)
 		{
-			(handler.PlatformView as IMauiRecyclerView<TItemsView>)?.UpdateHorizontalScrollBarVisibility();
+			(handler.PlatformView as IMauiRecyclerView<TItemsView>)?.UpdateVerticalScrollBarVisibility();
 		}
 
 		public static void MapItemTemplate(ItemsViewHandler<TItemsView> handler, ItemsView itemsView)

src/Controls/tests/TestCases.Android.Tests/snapshots/android/CollectionViewShouldHaveScrollBar.png

@@ -0,0 +1,15 @@
+<?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.Issue25468">
+  <CollectionView
+    VerticalScrollBarVisibility="Always"
+    x:Name="CollectionView">
+    <CollectionView.ItemTemplate>
+      <DataTemplate>
+        <Label Text="{Binding}"
+            AutomationId="{Binding}"/>
+      </DataTemplate>
+    </CollectionView.ItemTemplate>
+  </CollectionView>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue25468.xaml

@@ -0,0 +1,25 @@
+namespace Maui.Controls.Sample.Issues
+{
+	[Issue(IssueTracker.Github, 25468, "Collection view has no scroll bar", PlatformAffected.Android)]
+	public partial class Issue25468 : ContentPage
+	{
+		public Issue25468()
+		{
+			InitializeComponent();
+
+			// Modifying the scroll bar so that we can verify screenshot
+#if ANDROID
+			Microsoft.Maui.Controls.Handlers.Items.CollectionViewHandler.Mapper.AppendToMapping("CollectionViewHandler", (handler, view) =>
+			{
+				handler.PlatformView.ScrollbarFadingEnabled = false;
+				handler.PlatformView.ScrollBarFadeDuration = 20;
+				handler.PlatformView.ScrollBarSize = 50;
+				handler.PlatformView.ScrollBarStyle = Android.Views.ScrollbarStyles.OutsideInset;
+			});
+#endif
+
+			var items = Enumerable.Range(1, 100).Select(i => i.ToString()).ToList();
+			CollectionView.ItemsSource = items;
+		}
+	}
+}

src/Controls/tests/TestCases.HostApp/Issues/Issue25468.xaml.cs

@@ -0,0 +1,25 @@
+#if ANDROID
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue25468 : _IssuesUITest
+	{
+		public Issue25468(TestDevice testDevice) : base(testDevice)
+		{
+		}
+
+		public override string Issue => "Collection view has no scroll bar";
+
+		[Test]
+		[Category(UITestCategories.CollectionView)]
+		public void CollectionViewShouldHaveScrollBar()
+		{
+			App.WaitForElement("1");
+			VerifyScreenshot();
+		}
+	}
+}
+#endif

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue25468.cs

@@ -95,7 +95,7 @@
   </style>
 
   <style name="collectionViewTheme">
-    <item name="collectionViewStyle">@style/scrollViewScrollBars</item>
+    <item name="android:scrollbars">vertical|horizontal</item>
   </style>
 
   <style name="scrollViewTheme">