Merge pull request #8075 from pr8x/adorner-layer-canvas

Fixing Canvas positioning for AdornerLayer

src/Avalonia.Controls/Canvas.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Reactive.Concurrency;
 using Avalonia.Input;
 using Avalonia.Layout;
 
@@ -159,47 +160,57 @@ namespace Avalonia.Controls
         }
 
         /// <summary>
-        /// Arranges the control's children.
+        /// Arranges a single child.
         /// </summary>
-        /// <param name="finalSize">The size allocated to the control.</param>
+        /// <param name="child">The child to arrange.</param>
-        /// <returns>The space taken.</returns>
+        /// <param name="finalSize">The size allocated to the canvas.</param>
-        protected override Size ArrangeOverride(Size finalSize)
+        protected virtual void ArrangeChild(Control child, Size finalSize)
         {
-            foreach (Control child in Children)
+            double x = 0.0;
-            {
+            double y = 0.0;
-                double x = 0.0;
+            double elementLeft = GetLeft(child);
-                double y = 0.0;
-                double elementLeft = GetLeft(child);
 
-                if (!double.IsNaN(elementLeft))
+            if (!double.IsNaN(elementLeft))
-                {
+            {
-                    x = elementLeft;
+                x = elementLeft;
-                }
+            }
-                else
+            else
+            {
+                // Arrange with right.
+                double elementRight = GetRight(child);
+                if (!double.IsNaN(elementRight))
                 {
-                    // Arrange with right.
+                    x = finalSize.Width - child.DesiredSize.Width - elementRight;
-                    double elementRight = GetRight(child);
-                    if (!double.IsNaN(elementRight))
-                    {
-                        x = finalSize.Width - child.DesiredSize.Width - elementRight;
-                    }
                 }
+            }
 
-                double elementTop = GetTop(child);
+            double elementTop = GetTop(child);
-                if (!double.IsNaN(elementTop) )
+            if (!double.IsNaN(elementTop))
-                {
+            {
-                    y = elementTop;
+                y = elementTop;
-                }
+            }
-                else
+            else
+            {
+                double elementBottom = GetBottom(child);
+                if (!double.IsNaN(elementBottom))
                 {
-                    double elementBottom = GetBottom(child);
+                    y = finalSize.Height - child.DesiredSize.Height - elementBottom;
-                    if (!double.IsNaN(elementBottom))
-                    {
-                        y = finalSize.Height - child.DesiredSize.Height - elementBottom;
-                    }
                 }
+            }
 
-                child.Arrange(new Rect(new Point(x, y), child.DesiredSize));
+            child.Arrange(new Rect(new Point(x, y), child.DesiredSize));
+        }
+
+        /// <summary>
+        /// Arranges the control's children.
+        /// </summary>
+        /// <param name="finalSize">The size allocated to the control.</param>
+        /// <returns>The space taken.</returns>
+        protected override Size ArrangeOverride(Size finalSize)
+        {
+            foreach (Control child in Children)
+            {
+                ArrangeChild(child, finalSize);
             }
 
             return finalSize;

src/Avalonia.Controls/Primitives/AdornerLayer.cs

@@ -105,7 +105,7 @@ namespace Avalonia.Controls.Primitives
                     }
                     else
                     {
-                        child.Arrange(new Rect(finalSize));
+                        ArrangeChild((Control) child, finalSize);
                     }
                 }
             }