feat(itemsrepeater): Make the ItemRepeater available on netstandard 2.0

src/Uno.UI/UI/LayoutHelper.cs

@@ -261,6 +261,16 @@ internal static Size NumberOrDefault(this Size value, Size defaultValue)
 			);
 		}
 
+#if NETSTANDARD2_0
+		[Pure]
+		internal static bool IsFinite(this double value)
+			=> !IsInfinity(value) && !IsNaN(value);
+
+		[Pure]
+		internal static bool IsFinite(this float value)
+			=> !float.IsInfinity(value) && !float.IsNaN(value);
+#endif
+
 		[Pure]
 		internal static double FiniteOrDefault(this double value, double defaultValue)
 		{

src/Uno.UI/UI/Xaml/Controls/Primitives/Repeater/FlowLayout.OrientationBasedMeasures.cs

@@ -7,7 +7,11 @@ namespace Microsoft.UI.Xaml.Controls
 	partial class FlowLayout : OrientationBasedMeasures
 	{
 		private ScrollOrientation ScrollOrientation { get; set; }
-		ScrollOrientation OrientationBasedMeasures.ScrollOrientation => ScrollOrientation;
+		ScrollOrientation OrientationBasedMeasures.ScrollOrientation
+		{
+			get => ScrollOrientation;
+			set => ScrollOrientation = value;
+		}
 
 		private protected double Major(Size size) => ((OrientationBasedMeasures) this).Major(size);
 		private protected double Minor(Size size) => ((OrientationBasedMeasures) this).Minor(size); 

src/Uno.UI/UI/Xaml/Controls/Primitives/Repeater/FlowLayout.cs

@@ -7,6 +7,11 @@
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
 using static Microsoft.UI.Xaml.Controls._Tracing;
+#if NETSTANDARD2_0
+using _Float = Uno.UI.LayoutHelper;
+#else
+using _Float = System.Single;
+#endif
 
 namespace Microsoft.UI.Xaml.Controls
 {
@@ -45,7 +50,7 @@ public FlowLayout()
 			LayoutId = "FlowLayout";
 		}
 
-		#region IVirtualizingLayoutOverrides
+#region IVirtualizingLayoutOverrides
 		protected internal override void InitializeForContextCore(VirtualizingLayoutContext context)
 		{
 			var state = context.LayoutState;
@@ -110,9 +115,9 @@ protected internal override void OnItemsChangedCore(VirtualizingLayoutContext co
 			InvalidateLayout();
 		}
 
-		#endregion
+#endregion
 
-		#region IFlowLayoutOverrides
+#region IFlowLayoutOverrides
 
 		protected virtual Size GetMeasureSize(int index, Size availableSize)
 		{
@@ -222,7 +227,7 @@ protected virtual Rect GetExtent(
 					// If the available size is infinite, we will have realized all the items in one line.
 					// In that case, the extent in the non virtualizing direction should be based on the
 					// right/bottom of the last realized element.
-					SetMinorSize(ref extent, double.IsFinite(availableSizeMinor) ? availableSizeMinor : Math.Max(0.0f, MinorEnd(lastRealizedLayoutBounds)));
+					SetMinorSize(ref extent, _Float.IsFinite(availableSizeMinor) ? availableSizeMinor : Math.Max(0.0f, MinorEnd(lastRealizedLayoutBounds)));
 				}
 				else
 				{
@@ -231,7 +236,7 @@ protected virtual Rect GetExtent(
 					// We dont have anything realized. make an educated guess.
 					int numLines = (int)Math.Ceiling(itemsCount / averageItemsPerLine);
 					extent =
-						float.IsFinite(availableSizeMinor)
+						_Float.IsFinite(availableSizeMinor)
 							? MinorMajorRect(0, 0, availableSizeMinor, Math.Max(0.0f, (float)(numLines * averageLineSize - lineSpacing)))
 							: MinorMajorRect(
 								0,
@@ -282,9 +287,9 @@ protected virtual void OnLineArranged(
 			flowState.OnLineArranged(startIndex, countInLine, lineSize, context);
 		}
 
-		#endregion
+#endregion
 
-		#region IFlowLayoutAlgorithmDelegates
+#region IFlowLayoutAlgorithmDelegates
 
 		Size IFlowLayoutAlgorithmDelegates.Algorithm_GetMeasureSize(int index, Size availableSize, VirtualizingLayoutContext context)
 		{
@@ -370,7 +375,7 @@ void IFlowLayoutAlgorithmDelegates.Algorithm_OnLineArranged(
 				context);
 		}
 
-		#endregion
+#endregion
 
 		void OnPropertyChanged(DependencyPropertyChangedEventArgs args)
 		{
@@ -400,7 +405,7 @@ void OnPropertyChanged(DependencyPropertyChangedEventArgs args)
 			InvalidateLayout();
 		}
 
-		#region private helpers
+#region private helpers
 
 		double GetAverageLineInfo(
 
@@ -431,6 +436,6 @@ double GetAverageLineInfo(
 			return avgLineSize;
 		}
 
-		#endregion
+#endregion
 	}
 }

src/Uno.UI/UI/Xaml/Controls/Primitives/Repeater/FlowLayoutAlgorithm.OrientationBasedMeasures.cs

@@ -7,7 +7,11 @@ namespace Microsoft.UI.Xaml.Controls
 	partial class FlowLayoutAlgorithm : OrientationBasedMeasures
 	{
 		private ScrollOrientation ScrollOrientation { get; set; }
-		ScrollOrientation OrientationBasedMeasures.ScrollOrientation => ScrollOrientation;
+		ScrollOrientation OrientationBasedMeasures.ScrollOrientation
+		{
+			get => ScrollOrientation;
+			set => ScrollOrientation = value;
+		}
 
 		private protected double Major(Size size) => ((OrientationBasedMeasures)this).Major(size);
 		private protected double Minor(Size size) => ((OrientationBasedMeasures)this).Minor(size);

src/Uno.UI/UI/Xaml/Controls/Primitives/Repeater/FlowLayoutAlgorithm.cs

@@ -6,6 +6,11 @@
 using Windows.Foundation;
 using Windows.UI.Xaml;
 using static Microsoft.UI.Xaml.Controls._Tracing;
+#if NETSTANDARD2_0
+using _Double = Uno.UI.LayoutHelper;
+#else
+using _Double = System.Double;
+#endif
 
 namespace Microsoft.UI.Xaml.Controls
 {
@@ -386,7 +391,7 @@ void Generate(
 						{
 							// Does not fit, wrap to the previous row
 							var availableSizeMinor = Minor(availableSize);
-							SetMinorStart(ref currentBounds, double.IsFinite(availableSizeMinor) ? availableSizeMinor - Minor(desiredSize) : 0.0f);
+							SetMinorStart(ref currentBounds, _Double.IsFinite(availableSizeMinor) ? availableSizeMinor - Minor(desiredSize) : 0.0f);
 							SetMajorStart(ref currentBounds, lineOffset - Major(desiredSize) - (float)(lineSpacing));
 
 							if (lineNeedsReposition)

src/Uno.UI/UI/Xaml/Controls/Primitives/Repeater/ItemsRepeater.cs

@@ -21,9 +21,9 @@ namespace Microsoft.UI.Xaml.Controls
 {
 	public partial class ItemsRepeater : FrameworkElement, IPanel
 	{
-		private readonly UIElementCollection _children;
-		UIElementCollection IPanel.Children => _children;
-		internal IList<UIElement> Children => _children.AsUIElementList();
+		private readonly UIElementCollection _repeaterChildren;
+		UIElementCollection IPanel.Children => _repeaterChildren;
+		internal IList<UIElement> Children => _repeaterChildren.AsUIElementList();
 
 
 		// Change to 'true' to turn on debugging outputs in Output window
@@ -92,7 +92,7 @@ public ItemsRepeater()
 		{
 			//__RP_Marker_ClassById(RuntimeProfiler.ProfId_ItemsRepeater);
 
-			_children = new UIElementCollection(this);
+			_repeaterChildren = new UIElementCollection(this);
 			m_animationManager = new AnimationManager(this);
 			m_viewManager = new ViewManager(this);
 			//if (SharedHelpers.IsRS5OrHigher())

src/Uno.UI/UI/Xaml/Controls/Primitives/Repeater/OrientationBasedMeasures.cs

@@ -1,7 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License. See LICENSE in the project root for license information.
 using Windows.Foundation;
-using Android.Bluetooth;
 
 namespace Microsoft.UI.Xaml.Controls
 {
@@ -10,20 +9,23 @@ namespace Microsoft.UI.Xaml.Controls
 	//		 but it's actually **NOT** an interface!
 	internal interface OrientationBasedMeasures
 	{
-		private protected ScrollOrientation ScrollOrientation { get; } // = ScrollOrientation.Vertical; we cannot init properties of interfaces, however Vertical is already the default value!
+		ScrollOrientation ScrollOrientation { get; set; } // = ScrollOrientation.Vertical; we cannot init properties of interfaces, however Vertical is already the default value!
+	}
 
-		double Major(Size size)
-			=> ScrollOrientation == ScrollOrientation.Vertical ? size.Height : size.Width;
+	internal static class OrientationBasedMeasuresExtensions
+	{
+		public static double Major(this OrientationBasedMeasures obm, Size size)
+			=> obm.ScrollOrientation == ScrollOrientation.Vertical ? size.Height : size.Width;
 
-		double Minor(Size size)
-			=> ScrollOrientation == ScrollOrientation.Vertical ? size.Width : size.Height;
+		public static double Minor(this OrientationBasedMeasures obm, Size size)
+			=> obm.ScrollOrientation == ScrollOrientation.Vertical ? size.Width : size.Height;
 
-		double MajorSize(Rect rect)
-			=> ScrollOrientation == ScrollOrientation.Vertical ? rect.Height : rect.Width;
+		public static double MajorSize(this OrientationBasedMeasures obm, Rect rect)
+			=> obm.ScrollOrientation == ScrollOrientation.Vertical ? rect.Height : rect.Width;
 
-		public void SetMajorSize(ref Rect rect, double value)
+		public static void SetMajorSize(this OrientationBasedMeasures obm, ref Rect rect, double value)
 		{
-			if (ScrollOrientation == ScrollOrientation.Vertical)
+			if (obm.ScrollOrientation == ScrollOrientation.Vertical)
 			{
 				rect.Height = value;
 			}
@@ -33,12 +35,12 @@ public void SetMajorSize(ref Rect rect, double value)
 			}
 		}
 
-		double MinorSize(Rect rect)
-			=> ScrollOrientation == ScrollOrientation.Vertical ? rect.Width : rect.Height;
+		public static double MinorSize(this OrientationBasedMeasures obm, Rect rect)
+			=> obm.ScrollOrientation == ScrollOrientation.Vertical ? rect.Width : rect.Height;
 
-		public void SetMinorSize(ref Rect rect, double value)
+		public static void SetMinorSize(this OrientationBasedMeasures obm, ref Rect rect, double value)
 		{
-			if (ScrollOrientation == ScrollOrientation.Vertical)
+			if (obm.ScrollOrientation == ScrollOrientation.Vertical)
 			{
 				rect.Width = value;
 			}
@@ -48,30 +50,30 @@ public void SetMinorSize(ref Rect rect, double value)
 			}
 		}
 
-		public double MajorStart(Rect rect)
-			=> ScrollOrientation == ScrollOrientation.Vertical ? rect.Y : rect.X;
+		public static double MajorStart(this OrientationBasedMeasures obm, Rect rect)
+			=> obm.ScrollOrientation == ScrollOrientation.Vertical ? rect.Y : rect.X;
 
-		public void SetMajorStart(ref Rect rect, double value)
+		public static void SetMajorStart(this OrientationBasedMeasures obm, ref Rect rect, double value)
 		{
-			if (ScrollOrientation == ScrollOrientation.Vertical)
+			if (obm.ScrollOrientation == ScrollOrientation.Vertical)
 			{
 				rect.Y = value;
 			}
 			else
 			{
 				rect.X = value;
 			}
-		} 
+		}
 
-		public double MajorEnd(Rect rect)
-			=> ScrollOrientation == ScrollOrientation.Vertical ? rect.Y + rect.Height : rect.X + rect.Width;
+		public static double MajorEnd(this OrientationBasedMeasures obm, Rect rect)
+			=> obm.ScrollOrientation == ScrollOrientation.Vertical ? rect.Y + rect.Height : rect.X + rect.Width;
 
-		double MinorStart(Rect rect)
-			=> ScrollOrientation == ScrollOrientation.Vertical ? rect.X : rect.Y;
+		public static double MinorStart(this OrientationBasedMeasures obm, Rect rect)
+			=> obm.ScrollOrientation == ScrollOrientation.Vertical ? rect.X : rect.Y;
 
-		public void SetMinorStart(ref Rect rect, double value)
+		public static void SetMinorStart(this OrientationBasedMeasures obm, ref Rect rect, double value)
 		{
-			if (ScrollOrientation == ScrollOrientation.Vertical)
+			if (obm.ScrollOrientation == ScrollOrientation.Vertical)
 			{
 				rect.X = value;
 			}
@@ -81,9 +83,9 @@ public void SetMinorStart(ref Rect rect, double value)
 			}
 		}
 
-		public void AddMinorStart(ref Rect rect, double increment)
+		public static void AddMinorStart(this OrientationBasedMeasures obm, ref Rect rect, double increment)
 		{
-			if (ScrollOrientation == ScrollOrientation.Vertical)
+			if (obm.ScrollOrientation == ScrollOrientation.Vertical)
 			{
 				rect.X += increment;
 			}
@@ -93,18 +95,18 @@ public void AddMinorStart(ref Rect rect, double increment)
 			}
 		}
 
-		double MinorEnd(Rect rect)
-			=> ScrollOrientation == ScrollOrientation.Vertical ? rect.X + rect.Width : rect.Y + rect.Height;
+		public static double MinorEnd(this OrientationBasedMeasures obm, Rect rect)
+			=> obm.ScrollOrientation == ScrollOrientation.Vertical ? rect.X + rect.Width : rect.Y + rect.Height;
 
-		Rect MinorMajorRect(float minor, float major, float minorSize, float majorSize)
-			=> ScrollOrientation == ScrollOrientation.Vertical
+		public static Rect MinorMajorRect(this OrientationBasedMeasures obm, float minor, float major, float minorSize, float majorSize)
+			=> obm.ScrollOrientation == ScrollOrientation.Vertical
 				? new Rect(minor, major, minorSize, majorSize)
 				: new Rect(major, minor, majorSize, minorSize);
 
-		Point MinorMajorPoint(float minor, float major)
-			=> ScrollOrientation == ScrollOrientation.Vertical ? new Point(minor, major) : new Point(major, minor);
+		public static Point MinorMajorPoint(this OrientationBasedMeasures obm, float minor, float major)
+			=> obm.ScrollOrientation == ScrollOrientation.Vertical ? new Point(minor, major) : new Point(major, minor);
 
-		Size MinorMajorSize(float minor, float major)
-			=> ScrollOrientation == ScrollOrientation.Vertical ? new Size(minor, major) : new Size(major, minor);
+		public static Size MinorMajorSize(this OrientationBasedMeasures obm, float minor, float major)
+			=> obm.ScrollOrientation == ScrollOrientation.Vertical ? new Size(minor, major) : new Size(major, minor);
 	}
 }

src/Uno.UI/UI/Xaml/Controls/Primitives/Repeater/StackLayout.OrientationBasedMeasures.cs

@@ -7,7 +7,11 @@ namespace Microsoft.UI.Xaml.Controls
 	partial class StackLayout : OrientationBasedMeasures
 	{
 		private ScrollOrientation ScrollOrientation { get; set; }
-		ScrollOrientation OrientationBasedMeasures.ScrollOrientation => ScrollOrientation;
+		ScrollOrientation OrientationBasedMeasures.ScrollOrientation
+		{
+			get => ScrollOrientation;
+			set => ScrollOrientation = value;
+		}
 
 		private protected double Major(Size size) => ((OrientationBasedMeasures)this).Major(size);
 		private protected double Minor(Size size) => ((OrientationBasedMeasures)this).Minor(size);

src/Uno.UI/UI/Xaml/Controls/Primitives/Repeater/StackLayout.cs

@@ -7,6 +7,11 @@
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
 using static Microsoft.UI.Xaml.Controls._Tracing;
+#if NETSTANDARD2_0
+using _Double = Uno.UI.LayoutHelper;
+#else
+using _Double = System.Double;
+#endif
 
 namespace Microsoft.UI.Xaml.Controls
 {
@@ -222,7 +227,7 @@ Size IFlowLayoutAlgorithmDelegates.Algorithm_GetProvisionalArrangeSize(int index
 		{
 			var measureSizeMinor = Minor(measureSize);
 			return MinorMajorSize(
-				(float) (double.IsFinite(measureSizeMinor) ? Math.Max(measureSizeMinor, Minor(desiredSize)) : Minor(desiredSize)),
+				(float) (_Double.IsFinite(measureSizeMinor) ? Math.Max(measureSizeMinor, Minor(desiredSize)) : Minor(desiredSize)),
 				(float) Major(desiredSize));
 		}
 

src/Uno.UI/UI/Xaml/Controls/Primitives/Repeater/VirtualizationInfo.cs

@@ -4,7 +4,6 @@
 using System;
 using Windows.Foundation;
 using Windows.UI.Xaml.Markup;
-using Android.OS;
 using Uno.Extensions;
 
 namespace Microsoft.UI.Xaml.Controls