Updates to Kent Boogaart's Resizer control

I've used and abandoned the Resizer control a few times over the last couple years for various reasons. This time it seems it will be finding a permanent home in one of my apps. I had to make a modification to it and Blogger says I have too much text for a comment, so I'll make a new post.

I'm using Resizer inside a docking panel, so I wanted the width to stay tied to its parent panel. With that use case, I've added North, South, East, and West to the ResizeDirection enum. It's a pretty simple change, so I'll just post a few parts that people might miss if they wanted to reproduce it.

    private static void OnUpdateSizeCommand(object sender, ExecutedRoutedEventArgs e)
        {
            Resizer resizer = sender as Resizer;
            Debug.Assert(resizer != null);

            if (resizer._frameworkElement != null)
            {
                Point point = resizer._frameworkElement.PointToScreen(Mouse.GetPosition(resizer._frameworkElement));
                //If we're not adjusting the width or height, we want to leave it alone so it has its default sizing characteristics
                double? widthDelta = null;
                double? heightDelta = null;

                switch (resizer.ResizeDirection)
                {
               case ResizeDirection.North:
                  heightDelta = resizer._resizeOrigin.Y - point.Y;
                  break;
               case ResizeDirection.East:
                  widthDelta = point.X - resizer._resizeOrigin.X;
                  break;
               case ResizeDirection.South:
                  heightDelta = point.Y - resizer._resizeOrigin.Y;
                  break;
               case ResizeDirection.West:
                  widthDelta = resizer._resizeOrigin.X - point.X;
                  break;
               case ResizeDirection.NorthEast:
                  widthDelta = point.X - resizer._resizeOrigin.X;
                  heightDelta = resizer._resizeOrigin.Y - point.Y;
                  break;
               case ResizeDirection.NorthWest:
                        widthDelta = resizer._resizeOrigin.X - point.X;
                        heightDelta = resizer._resizeOrigin.Y - point.Y;
                        break;
                    case ResizeDirection.SouthEast:
                        widthDelta = point.X - resizer._resizeOrigin.X;
                        heightDelta = point.Y - resizer._resizeOrigin.Y;
                        break;
                    case ResizeDirection.SouthWest:
                        widthDelta = resizer._resizeOrigin.X - point.X;
                        heightDelta = point.Y - resizer._resizeOrigin.Y;
                        break;
                    default:
                        Debug.Fail("Unexpected ResizeDirection: " + resizer.ResizeDirection);
                        break;
                }

                //update the width and height, making sure we don't set to below zero
            if (widthDelta != null)
               resizer.Width = Math.Max(0, resizer._originalWidth + widthDelta.Value);
            if (heightDelta != null)
               resizer.Height = Math.Max(0, resizer._originalHeight + heightDelta.Value);
            }

            e.Handled = true;
        }

in GripAlignmentConverter.Convert:

            switch (orientation)
            {
                case Orientation.Horizontal:
               if (resizeDirection == ResizeDirection.NorthEast ||
                  resizeDirection == ResizeDirection.SouthEast ||
                  resizeDirection == ResizeDirection.South ||
                  resizeDirection == ResizeDirection.North)
                    {
                        return HorizontalAlignment.Right;
                    }
                    else
                    {
                        return HorizontalAlignment.Left;
                    }
                case Orientation.Vertical:
                    if (resizeDirection == ResizeDirection.NorthEast ||
                  resizeDirection == ResizeDirection.NorthWest ||
                  resizeDirection == ResizeDirection.North)
                    {
                        return VerticalAlignment.Top;
                    }
                    else
                    {
                        return VerticalAlignment.Bottom;
                    }
            }

new cases in GripCursorConverter.Convert

            case ResizeDirection.North:
            case ResizeDirection.South:
               return Cursors.SizeNS;
            case ResizeDirection.West:
            case ResizeDirection.East:
               return Cursors.SizeWE;

in GripRotationConverter:

            switch (resizeDirection)
            {
            case ResizeDirection.SouthWest:
                    return 90;
            case ResizeDirection.NorthWest:
            case ResizeDirection.West:
                    return 180;
            case ResizeDirection.NorthEast:
            case ResizeDirection.North:
                    return 270;
            }

If I've left something out or you're having problems, let me know.