Include Adorners in matrix calculations in VisualExtensions

AvaloniaUI · May 7, 2024 · e54d25f · e54d25f
1 parent 5271f80
commit e54d25f
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Showing 6 changed files with 108 additions and 32 deletions.
diff --git a/src/Avalonia.Base/Controls/AdornerLayerBase.cs b/src/Avalonia.Base/Controls/AdornerLayerBase.cs
@@ -0,0 +1,23 @@
+using Avalonia.Metadata;
+
+namespace Avalonia.Controls;
+
+[PrivateApi]
+public class AdornerLayerBase
+{
+    /// <summary>
+    /// Allows for getting and setting of the adorned element.
+    /// </summary>
+    public static readonly AttachedProperty<Visual?> AdornedElementProperty =
+        AvaloniaProperty.RegisterAttached<AdornerLayerBase, Visual, Visual?>("AdornedElement");
+
+    public static Visual? GetAdornedElement(Visual adorner)
+    {
+        return adorner.GetValue(AdornedElementProperty);
+    }
+
+    public static void SetAdornedElement(Visual adorner, Visual? adorned)
+    {
+        adorner.SetValue(AdornedElementProperty, adorned);
+    }
+}
diff --git a/src/Avalonia.Base/Controls/IAdornerLayer.cs b/src/Avalonia.Base/Controls/IAdornerLayer.cs
@@ -0,0 +1,9 @@
+using Avalonia.Metadata;
+
+namespace Avalonia.Controls;
+
+[PrivateApi]
+[NotClientImplementable]
+public interface IAdornerLayer
+{
+}
diff --git a/src/Avalonia.Base/VisualExtensions.cs b/src/Avalonia.Base/VisualExtensions.cs
@@ -1,4 +1,5 @@
 using System;
+using Avalonia.Controls;
 using Avalonia.VisualTree;
 
 namespace Avalonia
@@ -52,8 +53,21 @@ public static PixelPoint PointToScreen(this Visual visual, Point point)
 
             if (common != null)
             {
-                var thisOffset = GetOffsetFrom(common, from);
-                var thatOffset = GetOffsetFrom(common, to);
+                Matrix thisOffset;
+                if (TryGetAdorner(from, common, out var adornedFrom, out var adornerLayerFrom))
+                {
+                    thisOffset = GetOffsetFrom(common, adornedFrom!) * GetOffsetFrom(adornerLayerFrom!, from);
+                }
+                else
+                    thisOffset = GetOffsetFrom(common, from);
+
+                Matrix thatOffset;
+                if (TryGetAdorner(to, common, out var adornedTo, out var adornerLayerTo))
+                {
+                    thatOffset = GetOffsetFrom(common, adornedTo!) * GetOffsetFrom(adornerLayerTo!, to);
+                }
+                else
+                    thatOffset = GetOffsetFrom(common, to);
 
                 if (!thatOffset.TryInvert(out var thatOffsetInverted))
                 {
@@ -66,6 +80,29 @@ public static PixelPoint PointToScreen(this Visual visual, Point point)
             return null;
         }
 
+        private static bool TryGetAdorner(Visual target, Visual? stopAtVisual, out Visual? adorned, out Visual? adornerLayer)
+        {
+            var element = target;
+            while (element != null && element != stopAtVisual)
+            {
+                if (AdornerLayerBase.GetAdornedElement(element) is { } adornedElement)
+                {
+                    adorned = adornedElement;
+                    adornerLayer = element;
+                    while (adornerLayer != null && adornerLayer is not IAdornerLayer)
+                    {
+                        adornerLayer = adornerLayer.VisualParent;
+                    }
+                    return adornerLayer != null;
+                }
+                element = element.VisualParent;
+            }
+
+            adorned = null;
+            adornerLayer = null;
+            return false;
+        }
+
         /// <summary>
         /// Translates a point relative to this visual to coordinates that are relative to the specified visual.
         /// </summary>

diff --git a/src/Avalonia.Controls/Primitives/AdornerLayer.cs b/src/Avalonia.Controls/Primitives/AdornerLayer.cs
@@ -13,13 +13,13 @@ namespace Avalonia.Controls.Primitives
     /// <remarks>
     /// TODO: Need to track position of adorned elements and move the adorner if they move.
     /// </remarks>
-    public class AdornerLayer : Canvas
+    public class AdornerLayer : Canvas, IAdornerLayer
     {
         /// <summary>
         /// Allows for getting and setting of the adorned element.
         /// </summary>
         public static readonly AttachedProperty<Visual?> AdornedElementProperty =
-            AvaloniaProperty.RegisterAttached<AdornerLayer, Visual, Visual?>("AdornedElement");
+            AdornerLayerBase.AdornedElementProperty.AddOwner<AdornerLayer>();
 
         /// <summary>
         /// Allows for controlling clipping of the adorner.

diff --git a/src/Avalonia.Controls/Primitives/PopupPositioning/IPopupPositioner.cs b/src/Avalonia.Controls/Primitives/PopupPositioning/IPopupPositioner.cs
@@ -468,15 +468,7 @@ static class PopupPositionerExtensions
             {
                 if (target == null)
                     throw new InvalidOperationException("Placement mode is not Pointer and PlacementTarget is null");
-                Matrix? matrix;
-                if (TryGetAdorner(target, out var adorned, out var adornerLayer))
-                {
-                    matrix = adorned!.TransformToVisual(topLevel) * target.TransformToVisual(adornerLayer!);
-                }
-                else
-                {
-                    matrix = target.TransformToVisual(topLevel);
-                }
+                Matrix? matrix = target.TransformToVisual(topLevel);
 
                 if (matrix == null)
                 {
@@ -538,25 +530,6 @@ static class PopupPositionerExtensions
                 }
             }
         }
-
-        private static bool TryGetAdorner(Visual target, out Visual? adorned, out Visual? adornerLayer)
-        {
-            var element = target;
-            while (element != null)
-            {
-                if (AdornerLayer.GetAdornedElement(element) is { } adornedElement)
-                {
-                    adorned = adornedElement;
-                    adornerLayer = AdornerLayer.GetAdornerLayer(adorned);
-                    return true;
-                }
-                element = element.VisualParent;
-            }
-
-            adorned = null;
-            adornerLayer = null;
-            return false;
-        }
     }
 
 }
diff --git a/tests/Avalonia.Controls.UnitTests/AdornerLayerTests.cs b/tests/Avalonia.Controls.UnitTests/AdornerLayerTests.cs
@@ -0,0 +1,34 @@
+using Avalonia.Controls.Primitives;
+using Avalonia.UnitTests;
+using Xunit;
+
+namespace Avalonia.Controls.UnitTests;
+
+public class AdornerLayerTests : ScopedTestBase
+{
+    [Fact]
+    public void Adorners_Include_Adorned_Elements_In_Transform_Visual()
+    {
+        var button = new Button()
+        {
+            Margin = new Thickness(100, 100)
+        };
+        var root = new TestRoot()
+        {
+            Child = new VisualLayerManager()
+            {
+                Child = button
+            }
+        };
+        var adorner = new Border();
+
+        var adornerLayer = AdornerLayer.GetAdornerLayer(button);
+        adornerLayer.Children.Add(adorner);
+        AdornerLayer.SetAdornedElement(adorner, button);
+
+        root.LayoutManager.ExecuteInitialLayoutPass();
+
+        var translatedPoint = root.TranslatePoint(new Point(100, 100), adorner);
+        Assert.Equal(new Point(0, 0), translatedPoint);
+    }
+}