LayoutTests.cs

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License. See LICENSE in the project root for license information.

using Microsoft.UI.Xaml.Tests.MUXControls.ApiTests.RepeaterTests.Common;
using Microsoft.UI.Xaml.Tests.MUXControls.ApiTests.RepeaterTests.Common.Mocks;
using MUXControlsTestApp.Utilities;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Threading;
using Windows.Foundation;
using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;
using Microsoft.UI.Xaml.Controls.Primitives;
using Microsoft.UI.Xaml.Markup;
using Common;

#if USING_TAEF
using WEX.TestExecution;
using WEX.TestExecution.Markup;
using WEX.Logging.Interop;
#else
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Microsoft.VisualStudio.TestTools.UnitTesting.Logging;
#endif

using FlowLayoutLineAlignment = Microsoft/* UWP don't rename */.UI.Xaml.Controls.FlowLayoutLineAlignment;
using VirtualizingLayout = Microsoft/* UWP don't rename */.UI.Xaml.Controls.VirtualizingLayout;
using ItemsRepeater = Microsoft/* UWP don't rename */.UI.Xaml.Controls.ItemsRepeater;
using ElementFactory = Microsoft/* UWP don't rename */.UI.Xaml.Controls.ElementFactory;
using RecyclePool = Microsoft/* UWP don't rename */.UI.Xaml.Controls.RecyclePool;
using StackLayout = Microsoft/* UWP don't rename */.UI.Xaml.Controls.StackLayout;
using FlowLayout = Microsoft/* UWP don't rename */.UI.Xaml.Controls.FlowLayout;
using ItemsRepeaterScrollHost = Microsoft/* UWP don't rename */.UI.Xaml.Controls.ItemsRepeaterScrollHost;
using VirtualizingLayoutContext = Microsoft/* UWP don't rename */.UI.Xaml.Controls.VirtualizingLayoutContext;
using ElementRealizationOptions = Microsoft/* UWP don't rename */.UI.Xaml.Controls.ElementRealizationOptions;
using LayoutContext = Microsoft/* UWP don't rename */.UI.Xaml.Controls.LayoutContext;
using UniformGridLayout = Microsoft/* UWP don't rename */.UI.Xaml.Controls.UniformGridLayout;
using Microsoft.UI.Xaml.Media;
using Private.Infrastructure;
using System.Threading.Tasks;

namespace Microsoft.UI.Xaml.Tests.MUXControls.ApiTests.RepeaterTests
{
	[TestClass]
	public class LayoutTests : MUXApiTestBase
	{
		[TestMethod]
		[Ignore("UNO: Test does not pass yet with Uno https://github.com/unoplatform/uno/issues/4529")]
		public void ValidateMappingAndAutoRecycling()
		{
			ItemsRepeater repeater = null;
			ScrollViewer scrollViewer = null;
			RunOnUIThread.Execute(() =>
			{
				var layout = new MockVirtualizingLayout()
				{
					MeasureLayoutFunc = (availableSize, context) =>
					{
						var element0 = context.GetOrCreateElementAt(index: 0);
						// lookup - repeater will give back the same element and note that this element will not
						// be pinned - i.e it will be auto recycled after a measure pass where GetElementAt(0) is not called.
						var element0lookup = context.GetOrCreateElementAt(index: 0, options: ElementRealizationOptions.None);

						var element1 = context.GetOrCreateElementAt(index: 1, options: ElementRealizationOptions.ForceCreate | ElementRealizationOptions.SuppressAutoRecycle);
						// forcing a new element for index 1 that will be pinned (not auto recycled). This will be 
						// a completely new element. Repeater does not do the mapping/lookup when forceCreate is true.
						var element1Clone = context.GetOrCreateElementAt(index: 1, options: ElementRealizationOptions.ForceCreate | ElementRealizationOptions.SuppressAutoRecycle);

						Verify.AreSame(element0, element0lookup);
						Verify.AreNotSame(element1, element1Clone);

						element0.Measure(availableSize);
						element1.Measure(availableSize);
						element1Clone.Measure(availableSize);
						return new Size(100, 100);
					},
				};

				Content = CreateAndInitializeRepeater(
					itemsSource: Enumerable.Range(0, 5),
					layout: layout,
					elementFactory: GetDataTemplate("<Button>Hello</Button>"),
					repeater: ref repeater,
					scrollViewer: ref scrollViewer);

				Content.UpdateLayout();

				Verify.IsNotNull(repeater.TryGetElement(0));
				Verify.IsNotNull(repeater.TryGetElement(1));

				layout.MeasureLayoutFunc = null;

				repeater.InvalidateMeasure();
				Content.UpdateLayout();

				Verify.IsNull(repeater.TryGetElement(0)); // not pinned, should be auto recycled.
				Verify.IsNotNull(repeater.TryGetElement(1)); // pinned, should stay alive
			});
		}

		[TestMethod]
#if __IOS__ || __ANDROID__ || __MACOS__
		[Ignore("UNO: Test does not pass yet with Uno https://github.com/unoplatform/uno/issues/4529")]
#endif
		public void ValidateNonVirtualLayoutWithItemsRepeater()
		{
			RunOnUIThread.Execute(() =>
			{
				var repeater = new ItemsRepeater();
				repeater.Layout = new NonVirtualStackLayout();
				repeater.ItemsSource = Enumerable.Range(0, 10);
				repeater.ItemTemplate = (DataTemplate)XamlReader.Load(
					@"<DataTemplate  xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
						 <Button Content='{Binding}' Height='100' />
					</DataTemplate>");

				Content = repeater;
				Content.UpdateLayout();

				double expectedYOffset = 0;
				for (int i = 0; i < repeater.ItemsSourceView.Count; i++)
				{
					var child = repeater.TryGetElement(i) as Button;
					Verify.IsNotNull(child);
					var layoutBounds = LayoutInformation.GetLayoutSlot(child);
					Verify.AreEqual(expectedYOffset, layoutBounds.Y);
					Verify.AreEqual(i, child.Content);
					expectedYOffset += 100;
				}
			});
		}

		[TestMethod]
		[Ignore("UNO: Test does not pass yet with Uno https://github.com/unoplatform/uno/issues/4529")]
		public void ValidateNonVirtualLayoutDoesNotGetMeasuredForViewportChanges()
		{
			RunOnUIThread.Execute(() =>
			{
				int measureCount = 0;
				int arrangeCount = 0;
				var repeater = new ItemsRepeater();

				// with a non virtualizing layout, repeater will just
				// run layout once. 
				repeater.Layout = new MockNonVirtualizingLayout()
				{
					MeasureLayoutFunc = (size, context) =>
					{
						measureCount++;
						return new Size(100, 800);
					},
					ArrangeLayoutFunc = (size, context) =>
					{
						arrangeCount++;
						return new Size(100, 800);
					}
				};

				repeater.ItemsSource = Enumerable.Range(0, 10);
				repeater.ItemTemplate = (DataTemplate)XamlReader.Load(
					@"<DataTemplate  xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
						 <Button Content='{Binding}' Height='100' />
					</DataTemplate>");

				Content = new ScrollViewer()
				{
					Content = repeater
				};
				Content.UpdateLayout();

				Verify.AreEqual(1, measureCount);
				Verify.AreEqual(1, arrangeCount);

				measureCount = 0;
				arrangeCount = 0;

				// Once we switch to a virtualizing layout we should 
				// get at least two passes to update the viewport.
				repeater.Layout = new MockVirtualizingLayout()
				{
					MeasureLayoutFunc = (size, context) =>
					{
						measureCount++;
						return new Size(100, 800);
					},
					ArrangeLayoutFunc = (size, context) =>
					{
						arrangeCount++;
						return new Size(100, 800);
					}
				};

				Content.UpdateLayout();

				Verify.IsGreaterThan(measureCount, 1);
				Verify.IsGreaterThan(arrangeCount, 1);
			});
		}

		[TestMethod]
#if __IOS__
		[Ignore("UNO: Test does not pass yet with Uno (causes infinite layout cycle) https://github.com/unoplatform/uno/issues/4529")]
#endif
#if __MACOS__
		[Ignore("Currently fails on macOS, part of #9282 epic")]
#endif
		public void ValidateStackLayoutDisabledVirtualizationWithItemsRepeater()
		{
			RunOnUIThread.Execute(() =>
			{
				var repeater = new ItemsRepeater();
				var stackLayout = new StackLayout();
				stackLayout.DisableVirtualization = true;
				repeater.Layout = stackLayout;
				repeater.ItemsSource = Enumerable.Range(0, 10);
				repeater.ItemTemplate = (DataTemplate)XamlReader.Load(
					@"<DataTemplate  xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
						 <Button Content='{Binding}' Height='100' />
					</DataTemplate>");

				var scrollViewer = new ScrollViewer()
				{
					Content = repeater
				};
				scrollViewer.Height = 100;
				Content = scrollViewer;
				Content.UpdateLayout();

				for (int i = 0; i < repeater.ItemsSourceView.Count; i++)
				{
					var child = repeater.TryGetElement(i) as Button;
					Verify.IsNotNull(child);
				}
			});
		}

		[TestMethod]
		public void VerifyStackLayoutCycleShortcut()
		{
			RunOnUIThread.Execute(() =>
			{
				int measureCount = 0;
				int arrangeCount = 0;
				var repeater = new ItemsRepeater();
				var mockStackLayout = new MockStackLayout();

				mockStackLayout.MeasureLayoutFunc = (size, context) =>
				{
					// Simulating variable sized children that cause
					// the ItemsRepeater's layout to not settle.
					// This would normally cause a layout cycle but the use
					// of ItemsRepeater::m_stackLayoutMeasureCounter avoids it.
					mockStackLayout.InvalidateMeasure();
					measureCount++;
					return new Size(100, 200 + measureCount);
				};
				mockStackLayout.ArrangeLayoutFunc = (size, context) =>
				{
					arrangeCount++;
					return new Size(100, 200 + arrangeCount);
				};

				repeater.Layout = mockStackLayout;
				repeater.ItemsSource = Enumerable.Range(0, 10);
				repeater.ItemTemplate = GetDataTemplate("<Button Content='{Binding}' Height='200'/>");

				Content = repeater;
				Content.UpdateLayout();
			});
		}

		[TestMethod]
		[Ignore("Fails, itemsRepeaterOriginPoint.X is 0 at all times - https://github.com/unoplatform/uno/issues/8261")]
		public async Task VerifyStackLayoutAlignment()
		{
			for (int horizontalAlignment = 0; horizontalAlignment <= 3; horizontalAlignment++)
			{
				Border border = null;
				ItemsRepeater itemsRepeater = null;

				RunOnUIThread.Execute(() =>
				{
					itemsRepeater = new ItemsRepeater()
					{
						HorizontalAlignment = (HorizontalAlignment)horizontalAlignment,
						ItemsSource = Enumerable.Range(0, 2)
					};

					border = new Border()
					{
						Background = new SolidColorBrush(Colors.Azure),
						Width = 400,
						Height = 400,
						Child = itemsRepeater
					};

					Content = border;
				});

				await TestServices.WindowHelper.WaitForIdle();

				RunOnUIThread.Execute(() =>
				{
					Log.Comment($"ItemsRepeater.HorizontalAlignment set to {itemsRepeater.HorizontalAlignment}");
					Log.Comment($"ItemsRepeater actual size: {itemsRepeater.ActualWidth}, {itemsRepeater.ActualHeight}");

					Verify.AreEqual((HorizontalAlignment)horizontalAlignment, itemsRepeater.HorizontalAlignment);

					GeneralTransform gt = itemsRepeater.TransformToVisual(border);
					Point itemsRepeaterOriginPoint = new Point();
					itemsRepeaterOriginPoint = gt.TransformPoint(itemsRepeaterOriginPoint);
					Log.Comment($"ItemsRepeater position: {itemsRepeaterOriginPoint}");

					for (int itemIndex = 0; itemIndex <= 1; itemIndex++)
					{
						FrameworkElement itemElement = itemsRepeater.TryGetElement(itemIndex) as FrameworkElement;
						Verify.IsNotNull(itemElement);
						var layoutBounds = LayoutInformation.GetLayoutSlot(itemElement);
						Log.Comment($"ItemsRepeater child #{itemIndex} layout bounds: {layoutBounds}");
					}

					switch (itemsRepeater.HorizontalAlignment)
					{
						case HorizontalAlignment.Left:
						case HorizontalAlignment.Stretch:
							Verify.AreEqual(0, itemsRepeaterOriginPoint.X);
							break;
						case HorizontalAlignment.Center:
							Verify.IsTrue(itemsRepeaterOriginPoint.X > 0);
							Verify.AreEqual((border.ActualWidth - itemsRepeater.ActualWidth) / 2, itemsRepeaterOriginPoint.X);
							break;
						case HorizontalAlignment.Right:
							Verify.IsTrue(itemsRepeaterOriginPoint.X > 0);
							Verify.AreEqual(border.ActualWidth - itemsRepeater.ActualWidth, itemsRepeaterOriginPoint.X);
							break;
					}
				});
			}
		}

		[TestMethod]
		public async Task VerifyUniformGridLayoutDoesntCrashWhenTryingToScrollToEnd()
		{
			ItemsRepeater repeater = null;
			ScrollViewer scrollViewer = null;
			RunOnUIThread.Execute(() =>
			{
				repeater = new ItemsRepeater
				{
					ItemsSource = Enumerable.Range(0, 1000).Select(i => new Border
					{
						Background = new SolidColorBrush(Colors.Blue),
						Child = new TextBlock { Text = "#" + i }
					}).ToArray(),
					Layout = new UniformGridLayout
					{
						MinItemWidth = 100,
						MinItemHeight = 40,
						MinRowSpacing = 10,
						MinColumnSpacing = 10
					}
				};
				scrollViewer = new ScrollViewer { Content = repeater };
				Content = scrollViewer;
			});

			await TestServices.WindowHelper.WaitForIdle();

			RunOnUIThread.Execute(() =>
			{
				scrollViewer.ChangeView(0, repeater.ActualHeight, null);
			});

			await TestServices.WindowHelper.WaitForIdle();

			RunOnUIThread.Execute(() =>
			{
				scrollViewer.ChangeView(0, 0, null);
			});

			await TestServices.WindowHelper.WaitForIdle();

			// The test guards against an app crash, so this is enough to verify
			Verify.IsTrue(true);
		}

		[TestMethod]
#if !HAS_UNO_WINUI
		[Ignore("Fails on UWP")]
#endif
		public async Task VerifyUniformGridLayoutDoesntHangWhenTryingToScrollToStart()
		{
			ItemsRepeater itemsRepeater = null;
			ScrollViewer scrollViewer = null;
			ManualResetEvent viewChanged = new ManualResetEvent(false);

			RunOnUIThread.Execute(() =>
			{
				Log.Comment("Setting up UI.");

				itemsRepeater = new ItemsRepeater
				{
					ItemsSource = Enumerable.Range(0, 10).Select(_ => Enumerable.Range(1, 6).ToList()).ToList()
				};
				itemsRepeater.ItemTemplate = XamlReader.Load(
					@"<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
                          <ItemsRepeater ItemsSource='{Binding}'>
                              <ItemsRepeater.Layout>
                                  <UniformGridLayout
                                      Orientation='Horizontal'
                                      MinItemWidth='150.0'
                                      MaximumRowsOrColumns='3'
                                      MinRowSpacing='4'
                                      MinColumnSpacing='4'
                                      MinItemHeight='150.0'
                                      ItemsStretch='Fill'/>
                              </ItemsRepeater.Layout>
                              <ItemsRepeater.ItemTemplate>
                                  <DataTemplate>
                                      <TextBlock Text='{Binding}'/>
                                  </DataTemplate>
                              </ItemsRepeater.ItemTemplate>
                           </ItemsRepeater>
                      </DataTemplate>") as DataTemplate;

				scrollViewer = new ScrollViewer
				{
					Width = 500.0,
					Height = 400.0,
					Content = itemsRepeater
				};
				scrollViewer.ViewChanged += (sender, args) =>
				{
					Log.Comment($"ScrollViewer.ViewChanged raised for VerticalOffset '{scrollViewer.VerticalOffset}'.");

					if (!args.IsIntermediate)
					{
						Log.Comment("ScrollViewer.ChangeView completed.");

						viewChanged.Set();
					}
				};

				Content = scrollViewer;
				Content.UpdateLayout();
			});

			await TestServices.WindowHelper.WaitForIdle();

			Log.Comment("Scrolling to the bottom in 16 jumps...");

			for (int i = 1; i <= 16; i++)
			{
				RunOnUIThread.Execute(() =>
				{
					Log.Comment($"Jumping to VerticalOffset '{scrollViewer.ScrollableHeight * i / 16}'.");

					scrollViewer.ChangeView(null, scrollViewer.ScrollableHeight * i / 16, null, true);
				});

				Verify.IsTrue(viewChanged.WaitOne());
				viewChanged.Reset();
				await TestServices.WindowHelper.WaitForIdle();
			}

			Log.Comment("Scrolling to the top in 16 jumps...");

			for (int i = 15; i >= 0; i--)
			{
				RunOnUIThread.Execute(() =>
				{
					Log.Comment($"Jumping to VerticalOffset '{scrollViewer.ScrollableHeight * i / 16}'.");

					scrollViewer.ChangeView(null, scrollViewer.ScrollableHeight * i / 16, null, true);
				});

				Verify.IsTrue(viewChanged.WaitOne());
				viewChanged.Reset();
				await TestServices.WindowHelper.WaitForIdle();
			}
		}


		private ItemsRepeaterScrollHost CreateAndInitializeRepeater(
		   object itemsSource,
		   VirtualizingLayout layout,
		   object elementFactory,
		   ref ItemsRepeater repeater,
		   ref ScrollViewer scrollViewer)
		{
			repeater = new ItemsRepeater()
			{
				ItemsSource = itemsSource,
				Layout = layout,
				ItemTemplate = elementFactory,
				HorizontalCacheLength = 0,
				VerticalCacheLength = 0,
			};

			scrollViewer = new ScrollViewer()
			{
				Content = repeater
			};

			return new ItemsRepeaterScrollHost()
			{
				Width = 400,
				Height = 400,
				ScrollViewer = scrollViewer
			};
		}

		private DataTemplate GetDataTemplate(string content)
		{
			return (DataTemplate)XamlReader.Load(
					   string.Format(@"<DataTemplate  
							xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
						   {0}
						</DataTemplate>", content));
		}
	}
}