Refactor and enhance overlay feedback handling

- Promote `_containerPanel` to a protected property for better accessibility
- Extract `CoerceDelta` method to centralize constraint logic
- Implement `AnchorAndUpdatePositionInfo` across dialog controls for consistent positioning behavior
- Adjust margin binding for `DialogResizer` to include parent border margin
- Simplify pointer movement calculations and conditional checks

src/Ursa.Themes.Semi/Controls/Dialog.axaml

@@ -55,7 +55,7 @@
                             </Grid>
                         </Border>
                     </Border>
-                    <u:DialogResizer IsVisible="{TemplateBinding CanResize}" />
+                    <u:DialogResizer IsVisible="{TemplateBinding CanResize}" Margin="{Binding #PART_Border.Margin}" />
                 </Panel>
             </ControlTemplate>
         </Setter>
@@ -242,7 +242,7 @@
                             </Grid>
                         </Border>
                     </Border>
-                    <u:DialogResizer IsVisible="{TemplateBinding CanResize}"/>
+                    <u:DialogResizer IsVisible="{TemplateBinding CanResize}" Margin="{Binding #PART_Border.Margin}"/>
                 </Panel>
             </ControlTemplate>
         </Setter>

src/Ursa/Controls/Dialog/DialogControlBase.cs

@@ -204,4 +204,50 @@ public abstract class DialogControlBase : OverlayFeedbackElement
     }
 
     #endregion
+    
+    protected internal override void AnchorAndUpdatePositionInfo()
+    {
+        if (ContainerPanel is null) return;
+        ActualHorizontalAnchor = HorizontalPosition.Center;
+        ActualVerticalAnchor = VerticalPosition.Center;
+        double left = Canvas.GetLeft(this);
+        double top = Canvas.GetTop(this);
+        double right = ContainerPanel.Bounds.Width - left - Bounds.Width;
+        double bottom = ContainerPanel.Bounds.Height - top - Bounds.Height;
+        if (ContainerPanel is OverlayDialogHost h)
+        {
+            var snapThickness = h.SnapThickness;
+            if(top < snapThickness.Top)
+            {
+                Canvas.SetTop(this, 0);
+                ActualVerticalAnchor = VerticalPosition.Top;
+                VerticalOffsetRatio = 0;
+            }
+            if(bottom < snapThickness.Bottom)
+            {
+                Canvas.SetTop(this, ContainerPanel.Bounds.Height - Bounds.Height);
+                ActualVerticalAnchor = VerticalPosition.Bottom;
+                VerticalOffsetRatio = 1;
+            }
+            if(left < snapThickness.Left)
+            {
+                Canvas.SetLeft(this, 0);
+                ActualHorizontalAnchor = HorizontalPosition.Left;
+                HorizontalOffsetRatio = 0;
+            }
+            if(right < snapThickness.Right)
+            {
+                Canvas.SetLeft(this, ContainerPanel.Bounds.Width - this.Bounds.Width);
+                ActualHorizontalAnchor = HorizontalPosition.Right;
+                HorizontalOffsetRatio = 1;
+            }
+        }
+        left = Canvas.GetLeft(this);
+        top = Canvas.GetTop(this);
+        right = ContainerPanel.Bounds.Width - left - Bounds.Width;
+        bottom = ContainerPanel.Bounds.Height - top - Bounds.Height;
+
+        HorizontalOffsetRatio = (left + right) == 0 ? 0 : left / (left + right);
+        VerticalOffsetRatio = (top + bottom) == 0 ? 0 : top / (top + bottom);
+    }
 }

src/Ursa/Controls/Drawer/CustomDrawerControl.cs

@@ -25,4 +25,9 @@ public class CustomDrawerControl: DrawerControlBase
             OnElementClosing(this, null);
         }
     }
+
+    protected internal override void AnchorAndUpdatePositionInfo()
+    {
+        // throw new NotImplementedException();
+    }
 }

src/Ursa/Controls/Drawer/DefaultDrawerControl.cs

@@ -135,4 +135,9 @@ public class DefaultDrawerControl : DrawerControlBase
             RaiseEvent(new ResultEventArgs(ClosedEvent, result));
         }
     }
+
+    protected internal override void AnchorAndUpdatePositionInfo()
+    {
+        // throw new NotImplementedException();
+    }
 }

src/Ursa/Controls/OverlayShared/OverlayDialogHost.Dialog.cs

@@ -28,8 +28,8 @@ public partial class OverlayDialogHost
         }
         var width = newSize.Width - control.Bounds.Width;
         var height = newSize.Height - control.Bounds.Height;
-        var newLeft = width * control.HorizontalOffsetRatio??0;
+        var newLeft = width * control.HorizontalOffsetRatio ?? 0;
-        var newTop = height * control.VerticalOffsetRatio??0;
+        var newTop = height * control.VerticalOffsetRatio ?? 0;
         if(control.ActualHorizontalAnchor == HorizontalPosition.Left)
         {
             newLeft = 0;
@@ -91,7 +91,7 @@ public partial class OverlayDialogHost
     {
         if (e.Source is DialogControlBase item)
         {
-            AnchorAndUpdatePositionInfo(item);
+            item.AnchorAndUpdatePositionInfo();
         }
     }
 
@@ -230,48 +230,7 @@ public partial class OverlayDialogHost
         double top = GetTopPosition(control);
         SetLeft(control, left);
         SetTop(control, top);
-        AnchorAndUpdatePositionInfo(control);
+        control.AnchorAndUpdatePositionInfo();
-    }
-    
-    private void AnchorAndUpdatePositionInfo(DialogControlBase control)
-    {
-        control.ActualHorizontalAnchor = HorizontalPosition.Center;
-        control.ActualVerticalAnchor = VerticalPosition.Center;
-        double left = GetLeft(control);
-        double top = GetTop(control);
-        double right = Bounds.Width - left - control.Bounds.Width;
-        double bottom = Bounds.Height - top - control.Bounds.Height;
-        if(top < SnapThickness.Top)
-        {
-            SetTop(control, 0);
-            control.ActualVerticalAnchor = VerticalPosition.Top;
-            control.VerticalOffsetRatio = 0;
-        }
-        if(bottom < SnapThickness.Bottom)
-        {
-            SetTop(control, Bounds.Height - control.Bounds.Height);
-            control.ActualVerticalAnchor = VerticalPosition.Bottom;
-            control.VerticalOffsetRatio = 1;
-        }
-        if(left < SnapThickness.Left)
-        {
-            SetLeft(control, 0);
-            control.ActualHorizontalAnchor = HorizontalPosition.Left;
-            control.HorizontalOffsetRatio = 0;
-        }
-        if(right < SnapThickness.Right)
-        {
-            SetLeft(control, Bounds.Width - control.Bounds.Width);
-            control.ActualHorizontalAnchor = HorizontalPosition.Right;
-            control.HorizontalOffsetRatio = 1;
-        }
-        left = GetLeft(control);
-        top = GetTop(control);
-        right = Bounds.Width - left - control.Bounds.Width;
-        bottom = Bounds.Height - top - control.Bounds.Height;
-
-        control.HorizontalOffsetRatio = (left + right) == 0 ? 0 : left / (left + right);
-        control.VerticalOffsetRatio = (top + bottom) == 0 ? 0 : top / (top + bottom);
     }
 
     private double GetLeftPosition(DialogControlBase control)

src/Ursa/Controls/OverlayShared/OverlayFeedbackElement.cs

@@ -22,7 +22,7 @@ public abstract class OverlayFeedbackElement : ContentControl
     private bool _resizeDragging;
     private bool _moveDragging;
     
-    private Panel? _containerPanel;
+    protected Panel? ContainerPanel;
     private Rect _resizeDragStartBounds;
     private Point _resizeDragStartPoint;
     
@@ -110,7 +110,7 @@ public abstract class OverlayFeedbackElement : ContentControl
     protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
     {
         base.OnAttachedToVisualTree(e);
-        _containerPanel = this.FindAncestorOfType<Panel>();
+        ContainerPanel = this.FindAncestorOfType<Panel>();
     }
 
     protected override void OnPointerReleased(PointerReleasedEventArgs e)
@@ -130,73 +130,72 @@ public abstract class OverlayFeedbackElement : ContentControl
         base.OnPointerMoved(e);
         if (!_resizeDragging || _windowEdge is null) return;
         var point = e.GetPosition(this);
-        var diff = point - _resizeDragStartPoint;
+        Vector diff = point - _resizeDragStartPoint;
         var left = Canvas.GetLeft(this);
         var top = Canvas.GetTop(this);
         var width = _windowEdge is WindowEdge.West or WindowEdge.NorthWest or WindowEdge.SouthWest
             ? Bounds.Width : _resizeDragStartBounds.Width;
         var height = _windowEdge is WindowEdge.North or WindowEdge.NorthEast or WindowEdge.NorthWest
             ? Bounds.Height : _resizeDragStartBounds.Height;
-        var newBounds = CalculateNewBounds(left, top, width, height, diff, _containerPanel?.Bounds, _windowEdge.Value);
+        var newBounds = CalculateNewBounds(left, top, width, height, diff, ContainerPanel?.Bounds, _windowEdge.Value);
         Canvas.SetLeft(this, newBounds.Left);
         Canvas.SetTop(this, newBounds.Top);
         SetCurrentValue(WidthProperty, newBounds.Width);
         SetCurrentValue(HeightProperty, newBounds.Height);
     }
 
-    private Rect CalculateNewBounds(double left, double top, double width, double height, Point diff, Rect? containerBounds,
+    private Rect CalculateNewBounds(double left, double top, double width, double height, Vector diff, Rect? containerBounds,
         WindowEdge windowEdge)
     {
-        if (containerBounds is not null)
+        diff = CoerceDelta(left, top, width, height, diff, containerBounds, windowEdge);
-        {
-            var minX = windowEdge is WindowEdge.West or WindowEdge.NorthWest or WindowEdge.SouthWest
-                ? -left
-                : double.NegativeInfinity; 
-            var minY = windowEdge is WindowEdge.North or WindowEdge.NorthEast or WindowEdge.NorthWest
-                ? -top
-                : double.NegativeInfinity;
-            var maxX = containerBounds.Value.Width - left - MinWidth;
-            var maxY = containerBounds.Value.Height - top - MinHeight;
-            diff = new Point(MathHelpers.SafeClamp(diff.X, minX, maxX), MathHelpers.SafeClamp(diff.Y, minY, maxY));
-        }
         switch (windowEdge)
         {
             case WindowEdge.North:
-                top += diff.Y;
+                top += diff.Y; height -= diff.Y;
-                height -= diff.Y;
-                top = Math.Max(0, top);
                 break;
             case WindowEdge.NorthEast:
-                top += diff.Y;
+                top += diff.Y; width += diff.X; height -= diff.Y;
-                width += diff.X;
-                height -= diff.Y;
                 break;
             case WindowEdge.East:
                 width += diff.X;
                 break;
             case WindowEdge.SouthEast:
-                width += diff.X;
+                width += diff.X; height += diff.Y;
-                height += diff.Y;
                 break;
             case WindowEdge.South:
                 height += diff.Y;
                 break;
             case WindowEdge.SouthWest:
-                left += diff.X;
+                left += diff.X; width -= diff.X; height += diff.Y;
-                width -= diff.X;
-                height += diff.Y;
                 break;
             case WindowEdge.West:
-                left += diff.X;
+                left += diff.X; width -= diff.X;
-                width -= diff.X;
                 break;
             case WindowEdge.NorthWest:
-                left += diff.X;
+                top += diff.Y; width -= diff.X; height -= diff.Y;
-                top += diff.Y;
-                width -= diff.X;
-                height -= diff.Y;
                 break;
         }
         return new Rect(left, top, width, height);
     }
+
+    private Vector CoerceDelta(double left, double top, double width, double height, Vector diff, Rect? containerBounds,
+        WindowEdge windowEdge)
+    {
+        if (containerBounds is null) return diff;
+        var minX = windowEdge is WindowEdge.West or WindowEdge.NorthWest or WindowEdge.SouthWest
+            ? -left
+            : -width; 
+        var minY = windowEdge is WindowEdge.North or WindowEdge.NorthEast or WindowEdge.NorthWest
+            ? -top
+            : -height;
+        var maxX = windowEdge is WindowEdge.West or WindowEdge.NorthWest or WindowEdge.SouthWest
+            ? width-MinWidth
+            : containerBounds.Value.Width - left - width; 
+        var maxY = windowEdge is WindowEdge.North or WindowEdge.NorthEast or WindowEdge.NorthWest
+            ? height-MinWidth
+            : containerBounds.Value.Height - top - height;
+        return new Vector(MathHelpers.SafeClamp(diff.X, minX, maxX), MathHelpers.SafeClamp(diff.Y, minY, maxY));
+    }
+    
+    protected internal abstract void AnchorAndUpdatePositionInfo();
 }