private void graphCanvas_Paint(object sender, PaintEventArgs e)
{
// draw graph
_drawer.InitCanvas(graphCanvas.Size, e.Graphics);
_forestGraph.DrawWithPath(_drawer, _graphPath);
// draw rectangle
if (!_rectangle.Location.IsEmpty && !_rectangle.Size.IsEmpty && _rectangleDrawing)
{
RectangleF rectangle = new RectangleF(_rectangle.Location, _rectangle.Size);
_drawer.DrawRectangle(rectangle);
}
}