private void Ellipse_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            var ellipseClicked = sender as Ellipse;

            var window = new ElipseWindow(ellipseClicked)
            {
                Owner = this
            };

            window.ShowDialog();

            UpdateObjectValues(Cnv.Children.IndexOf(ellipseClicked), window.ResultedEllipse);
            e.Handled = true;
        }
        private void ElpiseSettings(Point mousePosition)
        {
            var window = new ElipseWindow()
            {
                Owner = this
            };

            window.ShowDialog();
            var ellipse = window.ResultedEllipse;

            if (ellipse != null)
            {
                ellipse.SetValue(Canvas.LeftProperty, mousePosition.X);
                ellipse.SetValue(Canvas.TopProperty, mousePosition.Y);
                ellipse.MouseLeftButtonUp += Ellipse_MouseLeftButtonUp;
                Cnv.Children.Add(ellipse);
                undoStack.Push(new Tuple <string, int, object>("add", Cnv.Children.IndexOf(ellipse), ellipse));
            }
        }