Merge branch 'master' into fix-next-draw-as

src/Avalonia.Controls/Repeater/ItemsRepeater.cs

@@ -10,6 +10,7 @@ using Avalonia.Controls.Templates;
 using Avalonia.Data;
 using Avalonia.Input;
 using Avalonia.Layout;
+using Avalonia.VisualTree;
 
 namespace Avalonia.Controls
 {
@@ -379,14 +380,19 @@ namespace Avalonia.Controls
         {
             if (property == ItemsProperty)
             {
+                var oldEnumerable = oldValue.GetValueOrDefault<IEnumerable>();
                 var newEnumerable = newValue.GetValueOrDefault<IEnumerable>();
-                var newDataSource = newEnumerable as ItemsSourceView;
+
-                if (newEnumerable != null && newDataSource == null)
+                if (oldEnumerable != newEnumerable)
                 {
-                    newDataSource = new ItemsSourceView(newEnumerable);
+                    var newDataSource = newEnumerable as ItemsSourceView;
-                }
+                    if (newEnumerable != null && newDataSource == null)
+                    {
+                        newDataSource = new ItemsSourceView(newEnumerable);
+                    }
 
-                OnDataSourcePropertyChanged(ItemsSourceView, newDataSource);
+                    OnDataSourcePropertyChanged(ItemsSourceView, newDataSource);
+                }
             }
             else if (property == ItemTemplateProperty)
             {
@@ -431,8 +437,16 @@ namespace Avalonia.Controls
 
         private int GetElementIndexImpl(IControl element)
         {
-            var virtInfo = TryGetVirtualizationInfo(element);
+            // Verify that element is actually a child of this ItemsRepeater
-            return _viewManager.GetElementIndex(virtInfo);
+            var parent = element.GetVisualParent();
+            
+            if (parent == this)
+            {
+                var virtInfo = TryGetVirtualizationInfo(element);
+                return _viewManager.GetElementIndex(virtInfo);
+            }
+
+            return -1;
         }
 
         private IControl GetElementFromIndexImpl(int index)

src/Avalonia.Controls/Repeater/ViewManager.cs

@@ -388,19 +388,24 @@ namespace Avalonia.Controls
                     }
 
                 case NotifyCollectionChangedAction.Reset:
-                    if (_owner.ItemsSourceView.HasKeyIndexMapping)
+                    // If we get multiple resets back to back before
+                    // running layout, we dont have to clear all the elements again.
+                    if (!_isDataSourceStableResetPending)
                     {
-                        _isDataSourceStableResetPending = true;
+                        if (_owner.ItemsSourceView.HasKeyIndexMapping)
-                    }
+                        {
+                            _isDataSourceStableResetPending = true;
+                        }
 
-                    // Walk through all the elements and make sure they are cleared, they will go into
+                        // Walk through all the elements and make sure they are cleared, they will go into
-                    // the stable id reset pool.
+                        // the stable id reset pool.
-                    foreach (var element in _owner.Children)
+                        foreach (var element in _owner.Children)
-                    {
-                        var virtInfo = ItemsRepeater.GetVirtualizationInfo(element);
-                        if (virtInfo.IsRealized && virtInfo.AutoRecycleCandidate)
                         {
-                            _owner.ClearElementImpl(element);
+                            var virtInfo = ItemsRepeater.GetVirtualizationInfo(element);
+                            if (virtInfo.IsRealized && virtInfo.AutoRecycleCandidate)
+                            {
+                                _owner.ClearElementImpl(element);
+                            }
                         }
                     }
 
@@ -441,6 +446,9 @@ namespace Avalonia.Controls
                 }
 
                 _resetPool.Clear();
+
+                // Flush the realized indices once the stable reset pool is cleared to start fresh.
+                InvalidateRealizedIndicesHeldByLayout();
             }
         }
 
@@ -498,6 +506,10 @@ namespace Avalonia.Controls
                     var virtInfo = ItemsRepeater.GetVirtualizationInfo(element);
                     virtInfo.MoveOwnershipToLayoutFromUniqueIdResetPool();
                     UpdateElementIndex(element, virtInfo, index);
+
+                    // Update realized indices
+                    _firstRealizedElementIndexHeldByLayout = Math.Min(_firstRealizedElementIndexHeldByLayout, index);
+                    _lastRealizedElementIndexHeldByLayout = Math.Max(_lastRealizedElementIndexHeldByLayout, index);
                 }
             }
 
@@ -519,6 +531,10 @@ namespace Avalonia.Controls
                     _pinnedPool.RemoveAt(i);
                     element = elementInfo.PinnedElement;
                     elementInfo.VirtualizationInfo.MoveOwnershipToLayoutFromPinnedPool();
+
+                    // Update realized indices
+                    _firstRealizedElementIndexHeldByLayout = Math.Min(_firstRealizedElementIndexHeldByLayout, index);
+                    _lastRealizedElementIndexHeldByLayout = Math.Max(_lastRealizedElementIndexHeldByLayout, index);
                     break;
                 }
             }

src/Avalonia.DesignerSupport/Remote/RemoteDesignerEntryPoint.cs

@@ -234,18 +234,10 @@ namespace Avalonia.DesignerSupport.Remote
                 }
                 catch (Exception e)
                 {
-                    var xmlException = e as XmlException;
-                    
                     s_transport.Send(new UpdateXamlResultMessage
                     {
                         Error = e.ToString(),
-                        Exception = new ExceptionDetails
+                        Exception = new ExceptionDetails(e),
-                        {
-                            ExceptionType = e.GetType().FullName,
-                            Message = e.Message.ToString(),
-                            LineNumber = xmlException?.LineNumber,
-                            LinePosition = xmlException?.LinePosition,
-                        }
                     });
                 }
             }

src/Avalonia.Layout/FlowLayoutAlgorithm.cs

@@ -74,6 +74,7 @@ namespace Avalonia.Layout
             double lineSpacing,
             int maxItemsPerLine,
             ScrollOrientation orientation,
+            bool disableVirtualization,
             string layoutId)
         {
             _orientation.ScrollOrientation = orientation;
@@ -95,14 +96,14 @@ namespace Avalonia.Layout
             _elementManager.OnBeginMeasure(orientation);
 
             int anchorIndex = GetAnchorIndex(availableSize, isWrapping, minItemSpacing, layoutId);
-            Generate(GenerateDirection.Forward, anchorIndex, availableSize, minItemSpacing, lineSpacing, maxItemsPerLine, layoutId);
+            Generate(GenerateDirection.Forward, anchorIndex, availableSize, minItemSpacing, lineSpacing, maxItemsPerLine, disableVirtualization, layoutId);
-            Generate(GenerateDirection.Backward, anchorIndex, availableSize, minItemSpacing, lineSpacing, maxItemsPerLine, layoutId);
+            Generate(GenerateDirection.Backward, anchorIndex, availableSize, minItemSpacing, lineSpacing, maxItemsPerLine, disableVirtualization, layoutId);
             if (isWrapping && IsReflowRequired())
             {
                 var firstElementBounds = _elementManager.GetLayoutBoundsForRealizedIndex(0);
                 _orientation.SetMinorStart(ref firstElementBounds, 0);
                 _elementManager.SetLayoutBoundsForRealizedIndex(0, firstElementBounds);
-                Generate(GenerateDirection.Forward, 0 /*anchorIndex*/, availableSize, minItemSpacing, lineSpacing, maxItemsPerLine, layoutId);
+                Generate(GenerateDirection.Forward, 0 /*anchorIndex*/, availableSize, minItemSpacing, lineSpacing, maxItemsPerLine, disableVirtualization, layoutId);
             }
 
             RaiseLineArranged();
@@ -273,6 +274,7 @@ namespace Avalonia.Layout
             double minItemSpacing,
             double lineSpacing,
             int maxItemsPerLine,
+            bool disableVirtualization,
             string layoutId)
         {
             if (anchorIndex != -1)
@@ -288,7 +290,7 @@ namespace Avalonia.Layout
                 bool lineNeedsReposition = false;
 
                 while (_elementManager.IsIndexValidInData(currentIndex) &&
-                    ShouldContinueFillingUpSpace(previousIndex, direction))
+                    (disableVirtualization || ShouldContinueFillingUpSpace(previousIndex, direction)))
                 {
                     // Ensure layout element.
                     _elementManager.EnsureElementRealized(direction == GenerateDirection.Forward, currentIndex, layoutId);

src/Avalonia.Layout/StackLayout.cs

@@ -14,6 +14,12 @@ namespace Avalonia.Layout
     /// </summary>
     public class StackLayout : VirtualizingLayout, IFlowLayoutAlgorithmDelegates
     {
+        /// <summary>
+        /// Defines the <see cref="DisableVirtualization"/> property.
+        /// </summary>
+        public static readonly StyledProperty<bool> DisableVirtualizationProperty =
+            AvaloniaProperty.Register<StackLayout, bool>(nameof(DisableVirtualization));
+
         /// <summary>
         /// Defines the <see cref="Orientation"/> property.
         /// </summary>
@@ -36,6 +42,15 @@ namespace Avalonia.Layout
             LayoutId = "StackLayout";
         }
 
+        /// <summary>
+        /// Gets or sets a value indicating whether virtualization is disabled on the layout.
+        /// </summary>
+        public bool DisableVirtualization
+        {
+            get => GetValue(DisableVirtualizationProperty);
+            set => SetValue(DisableVirtualizationProperty, value);
+        }
+
         /// <summary>
         /// Gets or sets the axis along which items are laid out.
         /// </summary>
@@ -262,6 +277,8 @@ namespace Avalonia.Layout
 
         protected internal override Size MeasureOverride(VirtualizingLayoutContext context, Size availableSize)
         {
+            ((StackLayoutState)context.LayoutState).OnMeasureStart();
+
             var desiredSize = GetFlowAlgorithm(context).Measure(
                 availableSize,
                 context,
@@ -270,6 +287,7 @@ namespace Avalonia.Layout
                 Spacing,
                 int.MaxValue,
                 _orientation.ScrollOrientation,
+                DisableVirtualization,
                 LayoutId);
 
             return new Size(desiredSize.Width, desiredSize.Height);
@@ -284,8 +302,6 @@ namespace Avalonia.Layout
                FlowLayoutAlgorithm.LineAlignment.Start,
                LayoutId);
 
-            ((StackLayoutState)context.LayoutState).OnArrangeLayoutEnd();
-
             return new Size(value.Width, value.Height);
         }
 

src/Avalonia.Layout/StackLayoutState.cs

@@ -56,6 +56,6 @@ namespace Avalonia.Layout
             MaxArrangeBounds = Math.Max(MaxArrangeBounds, minorSize);
         }
 
-        internal void OnArrangeLayoutEnd() => MaxArrangeBounds = 0;
+        internal void OnMeasureStart() => MaxArrangeBounds = 0;
     }
 }

src/Avalonia.Layout/UniformGridLayout.cs

@@ -433,6 +433,7 @@ namespace Avalonia.Layout
                 LineSpacing,
                 _maximumRowsOrColumns,
                 _orientation.ScrollOrientation,
+                false,
                 LayoutId);
 
             // If after Measure the first item is in the realization rect, then we revoke grid state's ownership,

src/Avalonia.Remote.Protocol/DesignMessages.cs

@@ -1,4 +1,7 @@
 using System;
+using System.Reflection;
+using System.Runtime.ExceptionServices;
+using System.Xml;
 
 namespace Avalonia.Remote.Protocol.Designer
 {
@@ -26,6 +29,27 @@ namespace Avalonia.Remote.Protocol.Designer
     
     public class ExceptionDetails
     {
+        public ExceptionDetails()
+        {
+        }
+
+        public ExceptionDetails(Exception e)
+        {
+            if (e is TargetInvocationException)
+            {
+                e = e.InnerException;
+            }
+
+            ExceptionType = e.GetType().Name;
+            Message = e.Message;
+
+            if (e is XmlException xml)
+            {
+                LineNumber = xml.LineNumber;
+                LinePosition = xml.LinePosition;
+            }
+        }
+
         public string ExceptionType { get; set; }
         public string Message { get; set; }
         public int? LineNumber { get; set; }

src/Avalonia.Visuals/Media/BoxShadows.cs

@@ -21,7 +21,7 @@ namespace Avalonia.Media
         {
             _first = shadow;
             _list = null;
-            Count = 1;
+            Count = _first.IsEmpty ? 0 : 1;
         }
 
         public BoxShadows(BoxShadow first, BoxShadow[] rest)
@@ -105,8 +105,6 @@ namespace Avalonia.Media
                 return false;
             }
         }
-
-        public static implicit operator BoxShadows(BoxShadow shadow) => new BoxShadows(shadow);
         
         public bool Equals(BoxShadows other)
         {

src/Avalonia.Visuals/Media/DrawingContext.cs

@@ -141,13 +141,13 @@ namespace Avalonia.Media
         /// <param name="radiusY">The radius in the Y dimension of the rounded corners.
         ///     This value will be clamped to the range of 0 to Height/2
         /// </param>
-        /// <param name="boxShadow">Box shadow effect parameters</param>
+        /// <param name="boxShadows">Box shadow effect parameters</param>
         /// <remarks>
         /// The brush and the pen can both be null. If the brush is null, then no fill is performed.
         /// If the pen is null, then no stoke is performed. If both the pen and the brush are null, then the drawing is not visible.
         /// </remarks>
         public void DrawRectangle(IBrush brush, IPen pen, Rect rect, double radiusX = 0, double radiusY = 0,
-            BoxShadow boxShadow = default)
+            BoxShadows boxShadows = default)
         {
             if (brush == null && !PenIsVisible(pen))
             {
@@ -164,7 +164,7 @@ namespace Avalonia.Media
                 radiusY = Math.Min(radiusY, rect.Height / 2);
             }
 
-            PlatformImpl.DrawRectangle(brush, pen, new RoundedRect(rect, radiusX, radiusY), boxShadow);
+            PlatformImpl.DrawRectangle(brush, pen, new RoundedRect(rect, radiusX, radiusY), boxShadows);
         }
 
         /// <summary>