private double m_dx1, m_dx2, m_dy1, m_dy2;
@Override
public void startDrag(DragContext dragContext)
{
Attributes attr = dragContext.getNode().asNode().getAttributes();
m_constraint = attr.getDragConstraint();
m_bounds = attr.getDragBounds();
if (m_bounds != null)
{
double x = attr.getX();
double y = attr.getY();
if (m_bounds.isX1()) m_dx1 = m_bounds.getX1() - x;
if (m_bounds.isX2()) m_dx2 = m_bounds.getX2() - x;