private void ehNowyClick(object sender, RoutedEventArgs e)
 {
     UDrawing.ClearAll();
     cDrawing.ClearAll();
     nowy     = true;
     modified = false;
 }
        /*dodanie sekwencio*/
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            UDrawing.ClearAll();
            cDrawing.ClearAll();
            nowy     = true;
            modified = false;

            AddUniterm au = new AddUniterm();

            au.ShowDialog();

            if (au.tbA.Text.Length > 250 || au.tbB.Text.Length > 250)
            {
                MessageBox.Show("Zbyt długi tekst!\n Maksymalna długość tekstu to 250 znaków!", "Błąd", MessageBoxButton.OK, MessageBoxImage.Error);
                return;
            }

            UDrawing.sA = au.tbA.Text;
            UDrawing.sB = au.tbB.Text;

            UDrawing.sOp = au.rbSr.IsChecked == true ? " ; " : " , ";


            btnRedraw_Click(sender, e);

            modified = true;
        }
        private void btnRedraw_Click(object sender, RoutedEventArgs e)
        {
            cDrawing.ClearAll();

            DrawingVisual dv = new DrawingVisual();

            using (DrawingContext dc = dv.RenderOpen())
            {
                UDrawing md = new UDrawing(dc);

                md.Redraw();
                dc.Close();
            }
            cDrawing.AddElement(dv);
        }