private void Rectangle_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            var rectangleClicked = sender as Rectangle;

            var window = new RectangleWindow(rectangleClicked)
            {
                Owner = this
            };

            window.ShowDialog();

            UpdateObjectValues(Cnv.Children.IndexOf(rectangleClicked), window.ResultedRectangle);
            e.Handled = true;
        }
        private void RectangleSettings(Point mousePosition)
        {
            var window = new RectangleWindow()
            {
                Owner = this
            };

            window.ShowDialog();
            var rectangle = window.ResultedRectangle;

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