Point2D pos = evt.getPoint2D();
AffineTransform transform = ua.getTransform();
if (transform != null && !transform.isIdentity())
transform.transform(pos, pos);
Point screen = ua.getClientAreaLocationOnScreen();
screen.translate((int)Math.floor(pos.getX()),
(int)Math.floor(pos.getY()));
// compute screen coordinates
GraphicsNode node = evt.getGraphicsNode();
Element elmt = context.getElement(node);
if (elmt == null) // should not appeared if binding on