Fixed ScrollView Orientation Neither issue (#27231)

* Fixed - 18418 : ScrollView Orientation=Neither not working

* updated ScrollViewerExtensions.cs

* Disable the scroll in ios when orientation is neither.

* updated ScrollViewHandler.iOS.cs

* testcases updated.

* Apply suggestions from code review

* Apply suggestions from code review

---------

Co-authored-by: Gerald Versluis <[email protected]>

Author: 2 people

src/Controls/tests/TestCases.HostApp/Issues/Issue2680ScrollView.cs

@@ -16,6 +16,11 @@ public void ToggleButtonText()
 
 		protected override void Init()
 		{
+			var contentView = new ContentView
+			{
+				HeightRequest = 2000
+			};
+
 			// Initialize ui here instead of ctor 
 			var longStackLayout = new StackLayout();
 
@@ -24,21 +29,26 @@ protected override void Init()
 
 			longStackLayout.Children.Add(toggleButton);
 
-			longStackLayout.Children.Add(new Label
-			{
-				Text = "First label",
-				AutomationId = FirstItemMark
-			});
+			firstItemLabel = new Label
+            {
+                Text = "Not scrolled",
+                AutomationId = FirstItemMark
+            };
+
+            longStackLayout.Children.Add(firstItemLabel);
 			Enumerable.Range(2, 50).Select(i => new Label { Text = $"Test label {i}" })
 				.ToList().ForEach(label => longStackLayout.Children.Add(label));
 
+			contentView.Content = longStackLayout;
+
 			scrollView = new ScrollView
 			{
 				Orientation = ScrollOrientation.Neither,
 				AutomationId = ScrollViewMark,
-				Content = longStackLayout
+				Content = contentView
 			};
 
+			scrollView.Scrolled += ScrollViewOnScrolled;
 			Content = scrollView;
 		}
 
@@ -48,9 +58,16 @@ void ToggleButtonOnClicked(object sender, EventArgs e)
 			scrollView.Orientation = IsScrollEnabled ? ScrollOrientation.Vertical : ScrollOrientation.Neither;
 		}
 
+		void ScrollViewOnScrolled(object sender, ScrolledEventArgs e)
+        {
+            firstItemLabel.Text = "Scrolled";
+        }
+
 		ScrollView scrollView;
 		Button toggleButton;
 
+		Label firstItemLabel;
+
 		const string ScrollViewMark = "ScrollView";
 		const string FirstItemMark = "FirstItem";
 		const string ToggleButtonMark = "ToggleButton";

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue2680ScrollView.cs

@@ -1,6 +1,4 @@
-#if TEST_FAILS_ON_WINDOWS && TEST_FAILS_ON_IOS && TEST_FAILS_ON_CATALYST // In iOS and Catalyst, WaitForNoElement throws a timeout exception eventhough the text is not visible on the screen by scrolling.
-//In Windows, The ScrollView remains scrollable even when ScrollOrientation.Neither is set. Issue Link: https://github.com/dotnet/maui/issues/27140
-using NUnit.Framework;
+using NUnit.Framework;
 using UITest.Appium;
 using UITest.Core;
 
@@ -20,32 +18,21 @@ public Issue2680ScrollView(TestDevice testDevice) : base(testDevice)
 
 		[Test]
 		[Category(UITestCategories.ScrollView)]
-		[FailsOnIOSWhenRunningOnXamarinUITest]
-		[FailsOnMacWhenRunningOnXamarinUITest]
 		public void Issue2680Test_ScrollDisabled()
 		{
-			App.WaitForElement(ScrollViewMark);
+			var label = App.WaitForElement(FirstItemMark);
 			App.ScrollDown(ScrollViewMark);
-			App.ScrollDown(ScrollViewMark);
-
-			App.WaitForElement(FirstItemMark, timeout: TimeSpan.FromSeconds(5));
+			Assert.That(label.GetText(), Is.EqualTo("Not scrolled"));
 		}
 
 		[Test]
 		[Category(UITestCategories.ScrollView)]
-		[FailsOnIOSWhenRunningOnXamarinUITest]
-		[FailsOnMacWhenRunningOnXamarinUITest]
-		[FailsOnWindowsWhenRunningOnXamarinUITest]
 		public void Issue2680Test_ScrollEnabled()
 		{
-			App.WaitForElement(ToggleButtonMark);
+			var label = App.WaitForElement(FirstItemMark);
 			App.Tap(ToggleButtonMark);
-
 			App.ScrollDown(ScrollViewMark);
-			App.ScrollDown(ScrollViewMark);
-
-			App.WaitForNoElement(FirstItemMark, timeout: TimeSpan.FromSeconds(5));
+			Assert.That(label.GetText(), Is.EqualTo("Scrolled"));
 		}
 	}
 }
-#endif

src/Core/src/Handlers/ScrollView/ScrollViewHandler.Windows.cs

@@ -62,7 +62,7 @@ public static void MapHorizontalScrollBarVisibility(IScrollViewHandler handler,
 
 		public static void MapVerticalScrollBarVisibility(IScrollViewHandler handler, IScrollView scrollView)
 		{
-			handler.PlatformView.VerticalScrollBarVisibility = scrollView.VerticalScrollBarVisibility.ToWindowsScrollBarVisibility();
+			handler.PlatformView?.UpdateScrollBarVisibility(scrollView.Orientation, scrollView.VerticalScrollBarVisibility);
 		}
 
 		public static void MapOrientation(IScrollViewHandler handler, IScrollView scrollView)

src/Core/src/Handlers/ScrollView/ScrollViewHandler.iOS.cs

@@ -83,6 +83,14 @@ public static void MapOrientation(IScrollViewHandler handler, IScrollView scroll
 				return;
 			}
 
+			if (scrollView.Orientation == ScrollOrientation.Neither)
+			{
+				platformView.ScrollEnabled = false;
+			}
+			else
+			{
+				platformView.ScrollEnabled = true;
+			}
 			platformView.InvalidateMeasure(scrollView);
 		}
 

src/Core/src/Platform/Windows/ScrollViewerExtensions.cs

@@ -19,35 +19,44 @@ public static WScrollBarVisibility ToWindowsScrollBarVisibility(this ScrollBarVi
 		public static void UpdateScrollBarVisibility(this ScrollViewer scrollViewer, ScrollOrientation orientation,
 			ScrollBarVisibility horizontalScrollBarVisibility)
 		{
+			if (orientation == ScrollOrientation.Neither)
+			{
+				scrollViewer.HorizontalScrollBarVisibility = scrollViewer.VerticalScrollBarVisibility = WScrollBarVisibility.Disabled;
+				return;
+			}
+
 			if (horizontalScrollBarVisibility == ScrollBarVisibility.Default)
 			{
 				// If the user has not explicitly set a horizontal scroll bar visibility, then the orientation will
 				// determine what the horizontal scroll bar does
-
 				scrollViewer.HorizontalScrollBarVisibility = orientation switch
 				{
 					ScrollOrientation.Horizontal or ScrollOrientation.Both => WScrollBarVisibility.Auto,
 					_ => WScrollBarVisibility.Disabled,
 				};
 
-				return;
+				scrollViewer.VerticalScrollBarVisibility = orientation switch
+				{
+					ScrollOrientation.Vertical or ScrollOrientation.Both => WScrollBarVisibility.Auto,
+					_ => WScrollBarVisibility.Disabled,
+				};
 			}
-
-			// If the user _has_ set a horizontal scroll bar visibility preference, then convert that preference to the native equivalent
-			// if the orientation allows for it
-
-			scrollViewer.HorizontalScrollBarVisibility = orientation switch
+			else
 			{
-				ScrollOrientation.Horizontal or ScrollOrientation.Both => horizontalScrollBarVisibility.ToWindowsScrollBarVisibility(),
-				_ => WScrollBarVisibility.Disabled,
-			};
-
-			// TODO ezhart 2021-07-08 RE: the note below - do we actually need to be accounting for Neither in the measurement code?
-			// Could we just disable the scroll bars entirely?
-			// Accounting for Neither in the xplat measurement code is a leftover from Forms, it may be easier to do that on the native side here.
+				// If the user _has_ set a horizontal scroll bar visibility preference, then convert that preference to the native equivalent
+				// if the orientation allows for it
+				scrollViewer.HorizontalScrollBarVisibility = orientation switch
+				{
+					ScrollOrientation.Horizontal or ScrollOrientation.Both => horizontalScrollBarVisibility.ToWindowsScrollBarVisibility(),
+					_ => WScrollBarVisibility.Disabled,
+				};
 
-			// Note that the Orientation setting of "Neither" is covered by the measurement code (the size of the content is limited
-			// so that no scrolling is possible) and the xplat scrolling code (the ScrollTo methods are disabled when Orientation=Neither)
+				scrollViewer.VerticalScrollBarVisibility = orientation switch
+				{
+					ScrollOrientation.Vertical or ScrollOrientation.Both => horizontalScrollBarVisibility.ToWindowsScrollBarVisibility(),
+					_ => WScrollBarVisibility.Disabled,
+				};
+			}
 		}
 
 		public static void UpdateContent(this ScrollViewer scrollViewer, IView? content, IMauiContext context)

src/Core/src/Platform/iOS/ScrollViewExtensions.cs

@@ -52,7 +52,14 @@ public static void UpdateContentSize(this UIScrollView scrollView, Size contentS
 
 		public static void UpdateIsEnabled(this UIScrollView nativeScrollView, IScrollView scrollView)
 		{
-			nativeScrollView.ScrollEnabled = scrollView.IsEnabled;
+			if (scrollView.Orientation == ScrollOrientation.Neither)
+			{
+				nativeScrollView.ScrollEnabled = false;
+			}
+			else
+			{
+				nativeScrollView.ScrollEnabled = scrollView.IsEnabled;
+			}
 		}
 	}
 }