private void UpdateCursor ()
{
//Control child_control = GrabControl.GetRealChildAtPoint (Cursor.Position);
//if (child_control != null) {
// if (active)
// XplatUI.SetCursor (child_control.Handle, Cursors.Default.handle);
// else
// XplatUI.SetCursor (child_control.Handle, child_control.Cursor.handle);
//}
}