Merge pull request #9590 from robloo/default-members

Standardize Default Members
3 years ago · 3ab5159960
50 changed files with 124 additions and 106 deletions
--- a/samples/ControlCatalog/Pages/ImagePage.xaml.cs
+++ b/samples/ControlCatalog/Pages/ImagePage.xaml.cs
@ -70,7 +70,7 @@ namespace ControlCatalog.Pages
                3 => new PixelRect(new PixelPoint(bitmapWidth - cropSize.Width, 0), cropSize),
                4 => new PixelRect(new PixelPoint(0, bitmapHeight - cropSize.Height), cropSize),
                5 => new PixelRect(new PixelPoint(bitmapWidth - cropSize.Width, bitmapHeight - cropSize.Height), cropSize),
-                _ => PixelRect.Empty
+                _ => default
            };
            
        }
--- a/src/Avalonia.Base/CornerRadius.cs
+++ b/src/Avalonia.Base/CornerRadius.cs
@ -61,9 +61,13 @@ namespace Avalonia
        public double BottomLeft { get; }

        /// <summary>
-        /// Gets a value indicating whether all corner radii are set to 0.
+        /// Gets a value indicating whether the instance has default values (all corner radii are set to 0).
        /// </summary>
-        public bool IsEmpty => TopLeft.Equals(0) && IsUniform;
+        public bool IsDefault => TopLeft == 0 && TopRight == 0 && BottomLeft == 0 && BottomRight == 0;
+
+        /// <inheritdoc cref="IsDefault"/>
+        [Obsolete("Use IsDefault instead.")]
+        public bool IsEmpty => IsDefault;

        /// <summary>
        /// Gets a value indicating whether all corner radii are equal.
@ -79,7 +83,6 @@ namespace Avalonia
        {
            // ReSharper disable CompareOfFloatsByEqualityOperator
            return TopLeft == other.TopLeft &&
-                   
                   TopRight == other.TopRight &&
                   BottomRight == other.BottomRight &&
                   BottomLeft == other.BottomLeft;
--- a/src/Avalonia.Base/Media/BoxShadow.cs
+++ b/src/Avalonia.Base/Media/BoxShadow.cs
@ -45,7 +45,14 @@ namespace Avalonia.Media
            }
        }

-        public bool IsEmpty => OffsetX == 0 && OffsetY == 0 && Blur == 0 && Spread == 0;
+        /// <summary>
+        /// Gets a value indicating whether the instance has default values.
+        /// </summary>
+        public bool IsDefault => OffsetX == 0 && OffsetY == 0 && Blur == 0 && Spread == 0;
+
+        /// <inheritdoc cref="IsDefault"/>
+        [Obsolete("Use IsDefault instead.")]
+        public bool IsEmpty => IsDefault;

        private readonly static char[] s_Separator = new char[] { ' ', '\t' };

@ -82,7 +89,7 @@ namespace Avalonia.Media
        {
            var sb = StringBuilderCache.Acquire();

-            if (IsEmpty)
+            if (IsDefault)
            {
                return "none";
            }
--- a/src/Avalonia.Base/Media/BoxShadows.cs
+++ b/src/Avalonia.Base/Media/BoxShadows.cs
@ -21,7 +21,7 @@ namespace Avalonia.Media
        {
            _first = shadow;
            _list = null;
-            Count = _first.IsEmpty ? 0 : 1;
+            Count = _first.IsDefault ? 0 : 1;
        }

        public BoxShadows(BoxShadow first, BoxShadow[] rest)
@ -120,7 +120,7 @@ namespace Avalonia.Media
            get
            {
                foreach(var boxShadow in this)
-                    if (!boxShadow.IsEmpty && boxShadow.IsInset)
+                    if (!boxShadow.IsDefault && boxShadow.IsInset)
                        return true;
                return false;
            }
--- a/src/Avalonia.Base/Media/FormattedText.cs
+++ b/src/Avalonia.Base/Media/FormattedText.cs
@ -1379,7 +1379,7 @@ namespace Avalonia.Media
                }
            }

-            if (accumulatedBounds?.PlatformImpl == null || accumulatedBounds.PlatformImpl.Bounds.IsEmpty)
+            if (accumulatedBounds?.PlatformImpl == null || accumulatedBounds.PlatformImpl.Bounds.IsDefault)
            {
                return null;
            }            
--- a/src/Avalonia.Base/Media/Geometry.cs
+++ b/src/Avalonia.Base/Media/Geometry.cs
@ -30,7 +30,7 @@ namespace Avalonia.Media
        /// <summary>
        /// Gets the geometry's bounding rectangle.
        /// </summary>
-        public Rect Bounds => PlatformImpl?.Bounds ?? Rect.Empty;
+        public Rect Bounds => PlatformImpl?.Bounds ?? default;

        /// <summary>
        /// Gets the platform-specific implementation of the geometry.
@ -84,7 +84,7 @@ namespace Avalonia.Media
        /// </summary>
        /// <param name="pen">The stroke thickness.</param>
        /// <returns>The bounding rectangle.</returns>
-        public Rect GetRenderBounds(IPen pen) => PlatformImpl?.GetRenderBounds(pen) ?? Rect.Empty;
+        public Rect GetRenderBounds(IPen pen) => PlatformImpl?.GetRenderBounds(pen) ?? default;

        /// <summary>
        /// Indicates whether the geometry's fill contains the specified point.
--- a/src/Avalonia.Base/Media/GeometryDrawing.cs
+++ b/src/Avalonia.Base/Media/GeometryDrawing.cs
@ -69,7 +69,7 @@ namespace Avalonia.Media
        public override Rect GetBounds()
        {
            IPen pen = Pen ?? s_boundsPen;
-			return Geometry?.GetRenderBounds(pen) ?? Rect.Empty;
+			return Geometry?.GetRenderBounds(pen) ?? default;
        }
    }
 }
--- a/src/Avalonia.Base/Media/GlyphRunDrawing.cs
+++ b/src/Avalonia.Base/Media/GlyphRunDrawing.cs
@ -32,7 +32,7 @@

        public override Rect GetBounds()
        {
-            return GlyphRun != null ? new Rect(GlyphRun.Size) : Rect.Empty;
+            return GlyphRun != null ? new Rect(GlyphRun.Size) : default;
        }
    }
 }
--- a/src/Avalonia.Base/Media/ImageDrawing.cs
+++ b/src/Avalonia.Base/Media/ImageDrawing.cs
@ -42,7 +42,7 @@ namespace Avalonia.Media
            var imageSource = ImageSource;
            var rect = Rect;

-            if (imageSource is object && !rect.IsEmpty)
+            if (imageSource is object && !rect.IsDefault)
            {
                context.DrawImage(imageSource, rect);
            }
--- a/src/Avalonia.Base/Media/Imaging/CroppedBitmap.cs
+++ b/src/Avalonia.Base/Media/Imaging/CroppedBitmap.cs
@ -78,8 +78,8 @@ namespace Avalonia.Media.Imaging
            get
            {
                if (Source is not IBitmap bmp)
-                    return Size.Empty;
-                if (SourceRect.IsEmpty)
+                    return default;
+                if (SourceRect.IsDefault)
                    return Source.Size;
                return SourceRect.Size.ToSizeWithDpi(bmp.Dpi);
            }
--- a/src/Avalonia.Base/Media/TextFormatting/TextLineImpl.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/TextLineImpl.cs
@ -532,7 +532,7 @@ namespace Avalonia.Media.TextFormatting

            var startX = Start;
            double currentWidth = 0;
-            var currentRect = Rect.Empty;
+            var currentRect = default(Rect);

            TextRunBounds lastRunBounds = default;

@ -748,7 +748,7 @@ namespace Avalonia.Media.TextFormatting

            var startX = WidthIncludingTrailingWhitespace;
            double currentWidth = 0;
-            var currentRect = Rect.Empty;
+            var currentRect = default(Rect);

            for (var index = TextRuns.Count - 1; index >= 0; index--)
            {
--- a/src/Avalonia.Base/PixelRect.cs
+++ b/src/Avalonia.Base/PixelRect.cs
@ -12,6 +12,7 @@ namespace Avalonia
        /// <summary>
        /// An empty rectangle.
        /// </summary>
+        [Obsolete("Use the default keyword instead.")]
        public static readonly PixelRect Empty = default;

        /// <summary>
@ -133,9 +134,13 @@ namespace Avalonia
        public PixelPoint Center => new PixelPoint(X + (Width / 2), Y + (Height / 2));

        /// <summary>
-        /// Gets a value that indicates whether the rectangle is empty.
+        /// Gets a value indicating whether the instance has default values (the rectangle is empty).
        /// </summary>
-        public bool IsEmpty => Width == 0 && Height == 0;
+        public bool IsDefault => Width == 0 && Height == 0;
+
+        /// <inheritdoc cref="IsDefault"/>
+        [Obsolete("Use IsDefault instead.")]
+        public bool IsEmpty => IsDefault;

        /// <summary>
        /// Checks for equality between two <see cref="PixelRect"/>s.
@ -257,7 +262,7 @@ namespace Avalonia
            }
            else
            {
-                return Empty;
+                return default;
            }
        }

@ -290,11 +295,11 @@ namespace Avalonia
        /// <returns>The union.</returns>
        public PixelRect Union(PixelRect rect)
        {
-            if (IsEmpty)
+            if (IsDefault)
            {
                return rect;
            }
-            else if (rect.IsEmpty)
+            else if (rect.IsDefault)
            {
                return this;
            }
--- a/src/Avalonia.Base/Rect.cs
+++ b/src/Avalonia.Base/Rect.cs
@ -18,7 +18,8 @@ namespace Avalonia
        /// <summary>
        /// An empty rectangle.
        /// </summary>
-        public static readonly Rect Empty = default(Rect);
+        [Obsolete("Use the default keyword instead.")]
+        public static readonly Rect Empty = default;

        /// <summary>
        /// The X position.
@ -169,12 +170,16 @@ namespace Avalonia
        public Point Center => new Point(_x + (_width / 2), _y + (_height / 2));

        /// <summary>
-        /// Gets a value that indicates whether the rectangle is empty.
+        /// Gets a value indicating whether the instance has default values (the rectangle is empty).
        /// </summary>
        // ReSharper disable CompareOfFloatsByEqualityOperator
-        public bool IsEmpty => _width == 0 && _height == 0;
+        public bool IsDefault => _width == 0 && _height == 0;
        // ReSharper restore CompareOfFloatsByEqualityOperator

+        /// <inheritdoc cref="IsDefault"/>
+        [Obsolete("Use IsDefault instead.")]
+        public bool IsEmpty => IsDefault;
+
        /// <summary>
        /// Checks for equality between two <see cref="Rect"/>s.
        /// </summary>
@ -390,7 +395,7 @@ namespace Avalonia
            }
            else
            {
-                return Empty;
+                return default;
            }
        }

@ -457,13 +462,13 @@ namespace Avalonia
 		/// </remarks>
 		public Rect Normalize()
        {
-            Rect rect = this;            
+            Rect rect = this;

            if(double.IsNaN(rect.Right) || double.IsNaN(rect.Bottom) || 
                double.IsNaN(rect.X) || double.IsNaN(rect.Y) || 
                double.IsNaN(Height) || double.IsNaN(Width))
            {
-                return Rect.Empty;
+                return default;
            }

            if (rect.Width < 0)
@ -493,11 +498,11 @@ namespace Avalonia
            /// <returns>The union.</returns>
            public Rect Union(Rect rect)
        {
-            if (IsEmpty)
+            if (IsDefault)
            {
                return rect;
            }
-            else if (rect.IsEmpty)
+            else if (rect.IsDefault)
            {
                return this;
            }
--- a/src/Avalonia.Base/Rendering/Composition/Server/DrawingContextProxy.cs
+++ b/src/Avalonia.Base/Rendering/Composition/Server/DrawingContextProxy.cs
@ -163,7 +163,7 @@ internal class CompositorDrawingContextProxy : IDrawingContextImpl, IDrawingCont
        public CompositionDrawList? VisualBrushDrawList { get; set; }
        public Size GetRenderTargetSize(IVisualBrush brush)
        {
-            return VisualBrushDrawList?.Size ?? Size.Empty;
+            return VisualBrushDrawList?.Size ?? default;
        }

        public void RenderVisualBrush(IDrawingContextImpl context, IVisualBrush brush)
--- a/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionDrawListVisual.cs
+++ b/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionDrawListVisual.cs
@ -37,7 +37,7 @@ internal class ServerCompositionDrawListVisual : ServerCompositionContainerVisua
        {
            if (_contentBounds == null)
            {
-                var rect = Rect.Empty;
+                var rect = default(Rect);
                if(_renderCommands!=null)
                    foreach (var cmd in _renderCommands)
                        rect = rect.Union(cmd.Item.Bounds);
--- a/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionTarget.cs
+++ b/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionTarget.cs
@ -90,7 +90,7 @@ namespace Avalonia.Rendering.Composition.Server

            Compositor.UpdateServerTime();
            
-            if(_dirtyRect.IsEmpty && !_redrawRequested)
+            if(_dirtyRect.IsDefault && !_redrawRequested)
                return;

            Revision++;
@ -119,7 +119,7 @@ namespace Avalonia.Rendering.Composition.Server
                    _dirtyRect = new Rect(0, 0, layerSize.Width, layerSize.Height);
                }

-                if (!_dirtyRect.IsEmpty)
+                if (!_dirtyRect.IsDefault)
                {
                    var visualBrushHelper = new CompositorDrawingContextProxy.VisualBrushRenderer();
                    using (var context = _layer.CreateDrawingContext(visualBrushHelper))
@ -162,7 +162,7 @@ namespace Avalonia.Rendering.Composition.Server
                }
                RenderedVisuals = 0;

-                _dirtyRect = Rect.Empty;
+                _dirtyRect = default;
            }
        }

@ -181,7 +181,7 @@ namespace Avalonia.Rendering.Composition.Server
        
        public void AddDirtyRect(Rect rect)
        {
-            if(rect.IsEmpty)
+            if(rect.IsDefault)
                return;
            var snapped = SnapToDevicePixels(rect, Scaling);
            DebugEvents?.RectInvalidated(rect);
--- a/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionVisual.cs
+++ b/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionVisual.cs
@ -37,7 +37,7 @@ namespace Avalonia.Rendering.Composition.Server
                return;

            currentTransformedClip = currentTransformedClip.Intersect(_combinedTransformedClipBounds);
-            if(currentTransformedClip.IsEmpty)
+            if(currentTransformedClip.IsDefault)
                return;

            Root!.RenderedVisuals++;
@ -139,7 +139,7 @@ namespace Avalonia.Rendering.Composition.Server
            if (ownBounds != _oldOwnContentBounds || positionChanged)
            {
                _oldOwnContentBounds = ownBounds;
-                if (ownBounds.IsEmpty)
+                if (ownBounds.IsDefault)
                    TransformedOwnContentBounds = default;
                else
                    TransformedOwnContentBounds =
@ -163,7 +163,7 @@ namespace Avalonia.Rendering.Composition.Server
            EffectiveOpacity = Opacity * (Parent?.EffectiveOpacity ?? 1);

            IsVisibleInFrame = _parent?.IsVisibleInFrame != false && Visible && EffectiveOpacity > 0.04 && !_isBackface &&
-                               !_combinedTransformedClipBounds.IsEmpty;
+                               !_combinedTransformedClipBounds.IsDefault;

            if (wasVisible != IsVisibleInFrame || positionChanged)
            {
@ -192,7 +192,7 @@ namespace Avalonia.Rendering.Composition.Server

        void AddDirtyRect(Rect rc)
        {
-            if(rc == Rect.Empty)
+            if(rc == default)
                return;
            Root?.AddDirtyRect(rc);
        }
--- a/src/Avalonia.Base/Rendering/DeferredRenderer.cs
+++ b/src/Avalonia.Base/Rendering/DeferredRenderer.cs
@ -309,7 +309,7 @@ namespace Avalonia.Rendering
        /// <inheritdoc/>
        Size IVisualBrushRenderer.GetRenderTargetSize(IVisualBrush brush)
        {
-            return TryGetChildScene(_currentDraw)?.Size ?? Size.Empty;
+            return TryGetChildScene(_currentDraw)?.Size ?? default;
        }

        /// <inheritdoc/>
@ -461,7 +461,7 @@ namespace Avalonia.Rendering
            {
                clipBounds = node.ClipBounds.Intersect(clipBounds);

-                if (!clipBounds.IsEmpty && node.Opacity > 0)
+                if (!clipBounds.IsDefault && node.Opacity > 0)
                {
                    var isLayerRoot = node.Visual == layer;

--- a/src/Avalonia.Base/Rendering/DirtyRects.cs
+++ b/src/Avalonia.Base/Rendering/DirtyRects.cs
@ -10,6 +10,9 @@ namespace Avalonia.Rendering
    {
        private List<Rect> _rects = new List<Rect>();

+        /// <summary>
+        /// Gets a value indicating whether the collection of dirty rectangles is empty.
+        /// </summary>
        public bool IsEmpty => _rects.Count == 0;

        /// <summary>
@ -27,7 +30,7 @@ namespace Avalonia.Rendering
        /// </remarks>
        public void Add(Rect rect)
        {
-            if (!rect.IsEmpty)
+            if (!rect.IsDefault)
            {
                for (var i = 0; i < _rects.Count; ++i)
                {
--- a/src/Avalonia.Base/Rendering/ImmediateRenderer.cs
+++ b/src/Avalonia.Base/Rendering/ImmediateRenderer.cs
@ -136,7 +136,7 @@ namespace Avalonia.Rendering
        /// <inheritdoc/>
        public void AddDirty(Visual visual)
        {
-            if (visual.Bounds != Rect.Empty)
+            if (!visual.Bounds.IsDefault)
            {
                var m = visual.TransformToVisual(_root);

@ -201,7 +201,7 @@ namespace Avalonia.Rendering
        Size IVisualBrushRenderer.GetRenderTargetSize(IVisualBrush brush)
        {
            (brush.Visual as IVisualBrushInitialize)?.EnsureInitialized();
-            return brush.Visual?.Bounds.Size ?? Size.Empty;
+            return brush.Visual?.Bounds.Size ?? default;
        }

        /// <inheritdoc/>
--- a/src/Avalonia.Base/Rendering/SceneGraph/BitmapBlendModeNode.cs
+++ b/src/Avalonia.Base/Rendering/SceneGraph/BitmapBlendModeNode.cs
@ -27,7 +27,7 @@ namespace Avalonia.Rendering.SceneGraph
        }

        /// <inheritdoc/>
-        public Rect Bounds => Rect.Empty;
+        public Rect Bounds => default;

        /// <summary>
        /// Gets the BitmapBlend to be pushed or null if the operation represents a pop.
--- a/src/Avalonia.Base/Rendering/SceneGraph/ClipNode.cs
+++ b/src/Avalonia.Base/Rendering/SceneGraph/ClipNode.cs
@ -40,7 +40,7 @@ namespace Avalonia.Rendering.SceneGraph
        }

        /// <inheritdoc/>
-        public Rect Bounds => Rect.Empty;
+        public Rect Bounds => default;

        /// <summary>
        /// Gets the clip to be pushed or null if the operation represents a pop.
--- a/src/Avalonia.Base/Rendering/SceneGraph/GeometryClipNode.cs
+++ b/src/Avalonia.Base/Rendering/SceneGraph/GeometryClipNode.cs
@ -28,7 +28,7 @@ namespace Avalonia.Rendering.SceneGraph
        }

        /// <inheritdoc/>
-        public Rect Bounds => Rect.Empty;
+        public Rect Bounds => default;

        /// <summary>
        /// Gets the clip to be pushed or null if the operation represents a pop.
--- a/src/Avalonia.Base/Rendering/SceneGraph/OpacityMaskNode.cs
+++ b/src/Avalonia.Base/Rendering/SceneGraph/OpacityMaskNode.cs
@ -19,7 +19,7 @@ namespace Avalonia.Rendering.SceneGraph
        /// <param name="bounds">The bounds of the mask.</param>
        /// <param name="aux">Auxiliary data required to draw the brush.</param>
        public OpacityMaskNode(IBrush mask, Rect bounds, IDisposable? aux = null)
-            : base(Rect.Empty, Matrix.Identity, aux)
+            : base(default, Matrix.Identity, aux)
        {
            Mask = mask.ToImmutable();
            MaskBounds = bounds;
@ -30,7 +30,7 @@ namespace Avalonia.Rendering.SceneGraph
        /// opacity mask pop.
        /// </summary>
        public OpacityMaskNode()
-            : base(Rect.Empty, Matrix.Identity, null)
+            : base(default, Matrix.Identity, null)
        {
        }

--- a/src/Avalonia.Base/Rendering/SceneGraph/OpacityNode.cs
+++ b/src/Avalonia.Base/Rendering/SceneGraph/OpacityNode.cs
@ -26,7 +26,7 @@ namespace Avalonia.Rendering.SceneGraph
        }

        /// <inheritdoc/>
-        public Rect Bounds => Rect.Empty;
+        public Rect Bounds => default;

        /// <summary>
        /// Gets the opacity to be pushed or null if the operation represents a pop.
--- a/src/Avalonia.Base/Rendering/SceneGraph/SceneBuilder.cs
+++ b/src/Avalonia.Base/Rendering/SceneGraph/SceneBuilder.cs
@ -331,8 +331,8 @@ namespace Avalonia.Rendering.SceneGraph

                scene.Size = newSize;

-                Rect horizontalDirtyRect = Rect.Empty;
-                Rect verticalDirtyRect = Rect.Empty;
+                Rect horizontalDirtyRect = default;
+                Rect verticalDirtyRect = default;

                if (newSize.Width > oldSize.Width)
                {
@ -429,7 +429,7 @@ namespace Avalonia.Rendering.SceneGraph
            else
            {
                layer.OpacityMask = null;
-                layer.OpacityMaskRect = Rect.Empty;
+                layer.OpacityMaskRect = default;
            }

            layer.GeometryClip = node.HasAncestorGeometryClip ?
--- a/src/Avalonia.Base/Size.cs
+++ b/src/Avalonia.Base/Size.cs
@ -28,8 +28,9 @@ namespace Avalonia
        public static readonly Size Infinity = new Size(double.PositiveInfinity, double.PositiveInfinity);

        /// <summary>
-        /// A size representing zero
+        /// A size representing zero.
        /// </summary>
+        [Obsolete("Use the default keyword instead.")]
        public static readonly Size Empty = new Size(0, 0);

        /// <summary>
@ -309,9 +310,6 @@ namespace Avalonia
        /// <summary>
        /// Gets a value indicating whether the Width and Height values are zero.
        /// </summary>
-        public bool IsDefault
-        {
-            get { return (_width == 0) && (_height == 0); }
-        }
+        public bool IsDefault => (_width == 0) && (_height == 0);
    }
 }
--- a/src/Avalonia.Base/Thickness.cs
+++ b/src/Avalonia.Base/Thickness.cs
@ -97,10 +97,9 @@ namespace Avalonia
        /// </summary>
        public double Bottom => _bottom;

-        /// <summary>
-        /// Gets a value indicating whether all sides are set to 0.
-        /// </summary>
-        public bool IsEmpty => Left.Equals(0) && IsUniform;
+        /// <inheritdoc cref="IsDefault"/>
+        [Obsolete("Use IsDefault instead.")]
+        public bool IsEmpty => IsDefault;

        /// <summary>
        /// Gets a value indicating whether all sides are equal.
@ -292,15 +291,13 @@ namespace Avalonia
            left = this._left;
            top = this._top;
            right = this._right;
-            bottom = this._bottom;        
+            bottom = this._bottom;
        }

        /// <summary>
-        /// Gets a value indicating whether the left, top, right and bottom thickness values are zero.
+        /// Gets a value indicating whether the instance has default values
+        /// (the left, top, right and bottom values are zero).
        /// </summary>
-        public bool IsDefault
-        {
-            get { return (_left == 0) && (_top == 0) && (_right == 0) && (_bottom == 0); }
-        }
+        public bool IsDefault => (_left == 0) && (_top == 0) && (_right == 0) && (_bottom == 0);
    }
 }
--- a/src/Avalonia.Controls.DataGrid/DataGrid.cs
+++ b/src/Avalonia.Controls.DataGrid/DataGrid.cs
@ -1123,7 +1123,7 @@ namespace Avalonia.Controls
                    EnsureColumnHeadersVisibility();
                    if (!newValueCols)
                    {
-                        _columnHeadersPresenter.Measure(Size.Empty);
+                        _columnHeadersPresenter.Measure(default(Size));
                    }
                    else
                    {
@ -1164,7 +1164,7 @@ namespace Avalonia.Controls
                _topLeftCornerHeader.IsVisible = newValueRows && newValueCols;
                if (_topLeftCornerHeader.IsVisible)
                {
-                    _topLeftCornerHeader.Measure(Size.Empty);
+                    _topLeftCornerHeader.Measure(default(Size));
                }
            }

--- a/src/Avalonia.Controls.DataGrid/DataGridCheckBoxColumn.cs
+++ b/src/Avalonia.Controls.DataGrid/DataGridCheckBoxColumn.cs
@ -192,14 +192,14 @@ namespace Avalonia.Controls
                    
                    void OnLayoutUpdated(object sender, EventArgs e)
                    {
-                        if(!editingCheckBox.Bounds.IsEmpty)
+                        if(!editingCheckBox.Bounds.IsDefault)
                        {
                            editingCheckBox.LayoutUpdated -= OnLayoutUpdated;
                            ProcessPointerArgs();
                        }
                    }

-                    if(editingCheckBox.Bounds.IsEmpty)
+                    if(editingCheckBox.Bounds.IsDefault)
                    {
                        editingCheckBox.LayoutUpdated += OnLayoutUpdated;
                    }
--- a/src/Avalonia.Controls.DataGrid/Primitives/DataGridCellsPresenter.cs
+++ b/src/Avalonia.Controls.DataGrid/Primitives/DataGridCellsPresenter.cs
@ -161,7 +161,7 @@ namespace Avalonia.Controls.Primitives
                {
                    // Clip
                    RectangleGeometry rg = new RectangleGeometry();
-                    rg.Rect = Rect.Empty;
+                    rg.Rect = default;
                    cell.Clip = rg;
                }
            }
--- a/src/Avalonia.Controls.DataGrid/Primitives/DataGridColumnHeadersPresenter.cs
+++ b/src/Avalonia.Controls.DataGrid/Primitives/DataGridColumnHeadersPresenter.cs
@ -305,7 +305,7 @@ namespace Avalonia.Controls.Primitives
            }
            if (!OwningGrid.AreColumnHeadersVisible)
            {
-                return Size.Empty;
+                return default;
            }
            double height = OwningGrid.ColumnHeaderHeight;
            bool autoSizeHeight;
--- a/src/Avalonia.Controls.DataGrid/Primitives/DataGridDetailsPresenter.cs
+++ b/src/Avalonia.Controls.DataGrid/Primitives/DataGridDetailsPresenter.cs
@ -112,7 +112,7 @@ namespace Avalonia.Controls.Primitives
        {
            if (OwningGrid == null || Children.Count == 0)
            {
-                return Size.Empty;
+                return default;
            }

            double desiredWidth = OwningGrid.AreRowDetailsFrozen ?
--- a/src/Avalonia.Controls/Flyouts/FlyoutBase.cs
+++ b/src/Avalonia.Controls/Flyouts/FlyoutBase.cs
@ -435,7 +435,7 @@ namespace Avalonia.Controls.Primitives
        {
            Size sz;
            // Popup.Child can't be null here, it was set in ShowAtCore.
-            if (Popup.Child!.DesiredSize == Size.Empty)
+            if (Popup.Child!.DesiredSize.IsDefault)
            {
                // Popup may not have been shown yet. Measure content
                sz = LayoutHelper.MeasureChild(Popup.Child, Size.Infinity, new Thickness());
@ -457,7 +457,7 @@ namespace Avalonia.Controls.Primitives
                    PopupPositioning.PopupPositionerConstraintAdjustment.SlideY;
            }

-            var trgtBnds = Target?.Bounds ?? Rect.Empty;
+            var trgtBnds = Target?.Bounds ?? default;

            switch (Placement)
            {
--- a/src/Avalonia.Controls/LayoutTransformControl.cs
+++ b/src/Avalonia.Controls/LayoutTransformControl.cs
@ -91,7 +91,7 @@ namespace Avalonia.Controls
            arrangedsize = TransformRoot.Bounds.Size;

            // This is the first opportunity under Silverlight to find out the Child's true DesiredSize
-            if (IsSizeSmaller(finalSizeTransformed, arrangedsize) && (Size.Empty == _childActualSize))
+            if (IsSizeSmaller(finalSizeTransformed, arrangedsize) && _childActualSize.IsDefault)
            {
                //// Unfortunately, all the work so far is invalid because the wrong DesiredSize was used
                //// Make a note of the actual DesiredSize
@ -102,7 +102,7 @@ namespace Avalonia.Controls
            else
            {
                // Clear the "need to measure/arrange again" flag
-                _childActualSize = Size.Empty;
+                _childActualSize = default;
            }

            // Return result to perform the transformation
@ -122,7 +122,7 @@ namespace Avalonia.Controls
            }

            Size measureSize;
-            if (_childActualSize == Size.Empty)
+            if (_childActualSize.IsDefault)
            {
                // Determine the largest size after the transformation
                measureSize = ComputeLargestTransformedSize(availableSize);
@ -206,7 +206,7 @@ namespace Avalonia.Controls
        /// <summary>
        /// Actual DesiredSize of Child element (the value it returned from its MeasureOverride method).
        /// </summary>
-        private Size _childActualSize = Size.Empty;
+        private Size _childActualSize = default;

        /// <summary>
        /// RenderTransform/MatrixTransform applied to TransformRoot.
@ -281,7 +281,7 @@ namespace Avalonia.Controls
        private Size ComputeLargestTransformedSize(Size arrangeBounds)
        {
            // Computed largest transformed size
-            Size computedSize = Size.Empty;
+            Size computedSize = default;

            // Detect infinite bounds and constrain the scenario
            bool infiniteWidth = double.IsInfinity(arrangeBounds.Width);
--- a/src/Avalonia.Controls/NativeControlHost.cs
+++ b/src/Avalonia.Controls/NativeControlHost.cs
@ -145,7 +145,7 @@ namespace Avalonia.Controls

            if (IsEffectivelyVisible && bounds.HasValue)
            {
-                if (bounds.Value.IsEmpty)
+                if (bounds.Value.IsDefault)
                    return false;
                _attachment?.ShowInBounds(bounds.Value);
            }
--- a/src/Avalonia.Controls/Presenters/ItemsPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/ItemsPresenter.cs
@ -77,7 +77,7 @@ namespace Avalonia.Controls.Presenters
        }

        /// <inheritdoc/>
-        Size IScrollable.Extent => Virtualizer?.Extent ?? Size.Empty;
+        Size IScrollable.Extent => Virtualizer?.Extent ?? default;

        /// <inheritdoc/>
        Vector IScrollable.Offset
@ -136,12 +136,12 @@ namespace Avalonia.Controls.Presenters
        /// <inheritdoc/>
        protected override Size MeasureOverride(Size availableSize)
        {
-            return Virtualizer?.MeasureOverride(availableSize) ?? Size.Empty;
+            return Virtualizer?.MeasureOverride(availableSize) ?? default;
        }

        protected override Size ArrangeOverride(Size finalSize)
        {
-            return Virtualizer?.ArrangeOverride(finalSize) ?? Size.Empty;
+            return Virtualizer?.ArrangeOverride(finalSize) ?? default;
        }

        /// <inheritdoc/>
--- a/src/Avalonia.Controls/Primitives/PopupPositioning/ManagedPopupPositioner.cs
+++ b/src/Avalonia.Controls/Primitives/PopupPositioning/ManagedPopupPositioner.cs
@ -112,7 +112,7 @@ namespace Avalonia.Controls.Primitives.PopupPositioning
                                   ?? screens.FirstOrDefault(s => s.Bounds.Intersects(parentGeometry))
                                   ?? screens.FirstOrDefault();

-                if (targetScreen != null && targetScreen.WorkingArea.IsEmpty)
+                if (targetScreen != null && targetScreen.WorkingArea.IsDefault)
                {
                    return targetScreen.Bounds;
                }
--- a/src/Avalonia.Controls/Repeater/ViewportManager.cs
+++ b/src/Avalonia.Controls/Repeater/ViewportManager.cs
@ -465,7 +465,7 @@ namespace Avalonia.Controls

            _pendingViewportShift = default;
            _unshiftableShift = default;
-            if (_visibleWindow.IsEmpty)
+            if (_visibleWindow.IsDefault)
            {
                // We got cleared.
                _layoutExtent = default;
@ -551,7 +551,7 @@ namespace Avalonia.Controls
        private void TryInvalidateMeasure()
        {
            // Don't invalidate measure if we have an invalid window.
-            if (!_visibleWindow.IsEmpty)
+            if (!_visibleWindow.IsDefault)
            {
                // We invalidate measure instead of just invalidating arrange because
                // we don't invalidate measure in UpdateViewport if the view is changing to
--- a/src/Avalonia.Controls/Shapes/Shape.cs
+++ b/src/Avalonia.Controls/Shapes/Shape.cs
@ -292,7 +292,7 @@ namespace Avalonia.Controls.Shapes
                return finalSize;
            }

-            return Size.Empty;
+            return default;
        }

        internal static (Size size, Matrix transform) CalculateSizeAndTransform(Size availableSize, Rect shapeBounds, Stretch Stretch)
--- a/src/Avalonia.Headless/HeadlessPlatformRenderInterface.cs
+++ b/src/Avalonia.Headless/HeadlessPlatformRenderInterface.cs
@ -215,7 +215,7 @@ namespace Avalonia.Headless

        class HeadlessStreamingGeometryStub : HeadlessGeometryStub, IStreamGeometryImpl
        {
-            public HeadlessStreamingGeometryStub() : base(Rect.Empty)
+            public HeadlessStreamingGeometryStub() : base(default)
            {
            }

--- a/src/Browser/Avalonia.Browser/WebEmbeddableControlRoot.cs
+++ b/src/Browser/Avalonia.Browser/WebEmbeddableControlRoot.cs
@ -18,7 +18,7 @@ namespace Avalonia.Browser
                _onFirstRender = onFirstRender;
            }

-            public Rect Bounds => Rect.Empty;
+            public Rect Bounds => default;

            public bool HasRendered => _hasRendered;

--- a/src/Skia/Avalonia.Skia/DrawingContextImpl.cs
+++ b/src/Skia/Avalonia.Skia/DrawingContextImpl.cs
@ -362,7 +362,7 @@ namespace Avalonia.Skia

            foreach (var boxShadow in boxShadows)
            {
-                if (!boxShadow.IsEmpty && !boxShadow.IsInset)
+                if (!boxShadow.IsDefault && !boxShadow.IsInset)
                {
                    using (var shadow = BoxShadowFilter.Create(_boxShadowPaint, boxShadow, _currentOpacity))
                    {
@ -418,7 +418,7 @@ namespace Avalonia.Skia

            foreach (var boxShadow in boxShadows)
            {
-                if (!boxShadow.IsEmpty && boxShadow.IsInset)
+                if (!boxShadow.IsDefault && boxShadow.IsInset)
                {
                    using (var shadow = BoxShadowFilter.Create(_boxShadowPaint, boxShadow, _currentOpacity))
                    {
--- a/src/Skia/Avalonia.Skia/GeometryImpl.cs
+++ b/src/Skia/Avalonia.Skia/GeometryImpl.cs
@ -244,7 +244,7 @@ namespace Avalonia.Skia
            public void Invalidate()
            {
                CachedStrokePath?.Dispose();
-                CachedGeometryRenderBounds = Rect.Empty;
+                CachedGeometryRenderBounds = default;
                _cachedStrokeWidth = default(float);
            }
        }
--- a/src/Skia/Avalonia.Skia/StreamGeometryImpl.cs
+++ b/src/Skia/Avalonia.Skia/StreamGeometryImpl.cs
@ -34,7 +34,7 @@ namespace Avalonia.Skia
        /// <summary>
        /// Initializes a new instance of the <see cref="StreamGeometryImpl"/> class.
        /// </summary>
-        public StreamGeometryImpl() : this(CreateEmptyPath(), Rect.Empty)
+        public StreamGeometryImpl() : this(CreateEmptyPath(), default)
        {
        }
        
--- a/tests/Avalonia.Base.UnitTests/RectTests.cs
+++ b/tests/Avalonia.Base.UnitTests/RectTests.cs
@ -52,7 +52,7 @@ namespace Avalonia.Base.UnitTests
                double.PositiveInfinity, double.PositiveInfinity)
                .Normalize();

-            Assert.Equal(Rect.Empty, result);
+            Assert.Equal(default, result);
        }
    }
 }
--- a/tests/Avalonia.Base.UnitTests/Rendering/DeferredRendererTests_HitTesting.cs
+++ b/tests/Avalonia.Base.UnitTests/Rendering/DeferredRendererTests_HitTesting.cs
@ -403,7 +403,7 @@ namespace Avalonia.Base.UnitTests.Rendering
                root.Measure(Size.Infinity);
                root.Arrange(new Rect(container.DesiredSize));
                
-                root.Renderer.Paint(Rect.Empty);
+                root.Renderer.Paint(default);
                var result = root.Renderer.HitTest(new Point(50, 150), root, null).First();

                Assert.Equal(item1, result);
@ -419,7 +419,7 @@ namespace Avalonia.Base.UnitTests.Rendering
                container.InvalidateArrange();
                container.Arrange(new Rect(container.DesiredSize));

-                root.Renderer.Paint(Rect.Empty);
+                root.Renderer.Paint(default);
                result = root.Renderer.HitTest(new Point(50, 150), root, null).First();
                Assert.Equal(item2, result);

--- a/tests/Avalonia.Base.UnitTests/Rendering/SceneGraph/DrawOperationTests.cs
+++ b/tests/Avalonia.Base.UnitTests/Rendering/SceneGraph/DrawOperationTests.cs
@ -13,9 +13,9 @@ namespace Avalonia.Base.UnitTests.Rendering.SceneGraph
        [Fact]
        public void Empty_Bounds_Remain_Empty()
        {
-            var target = new TestDrawOperation(Rect.Empty, Matrix.Identity, null);
+            var target = new TestDrawOperation(default, Matrix.Identity, null);

-            Assert.Equal(Rect.Empty, target.Bounds);
+            Assert.Equal(default, target.Bounds);
        }

        [Theory]
--- a/tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests_Virtualization_Simple.cs
+++ b/tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests_Virtualization_Simple.cs
@ -569,8 +569,8 @@ namespace Avalonia.Controls.UnitTests.Presenters
                var target = CreateTarget(itemCount: 10);
                var items = (IList<string>)target.Items;
                target.ApplyTemplate();
-                target.Measure(Size.Empty);
-                target.Arrange(Rect.Empty);
+                target.Measure(default(Size));
+                target.Arrange(default);

                // Check for issue #591: this should not throw.
                target.ScrollIntoView(0);
--- a/tests/Avalonia.Controls.UnitTests/Shapes/RectangleTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Shapes/RectangleTests.cs
@ -18,7 +18,7 @@ namespace Avalonia.Controls.UnitTests.Shapes
            target.Measure(new Size(100, 100));

            var geometry = Assert.IsType<RectangleGeometry>(target.RenderedGeometry);
-            Assert.Equal(Rect.Empty, geometry.Rect);
+            Assert.Equal(default, geometry.Rect);
        }

        [Fact]