private void CanvasUserDrawing_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
 {
     IDrawOnCanvas.AddFigurePoint(e.GetPosition(CanvasUserDrawing), ref currentFigure);
     IDrawOnCanvas.EndFigure(ref currentFigure);
     isDrawing = false;
     Mouse.Capture(null);
 }
 private void CanvasUserDrawing_MouseMove(object sender, MouseEventArgs e)
 {
     if (!isDrawing)
     {
         return;
     }
     IDrawOnCanvas.AddFigurePoint(e.GetPosition(CanvasUserDrawing), ref currentFigure);
 }
 private void BtCleanUpCnv_Click(object sender, RoutedEventArgs e)
 {
     IDrawOnCanvas.CanvasClean(ref CanvasUserDrawing);
 }
 private void CanvasUserDrawing_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
 {
     Mouse.Capture(CanvasUserDrawing);
     isDrawing = true;
     IDrawOnCanvas.StartFigure(e.GetPosition(CanvasUserDrawing), ref CanvasUserDrawing, ref currentFigure);
 }