// feed keys to focus is present and enabled, else the control display gets them

        protected void Gc_KeyUp(object sender, GLKeyEventArgs e)
        {
            if (currentfocus != null && currentfocus.Enabled)
            {
                if (!(currentfocus is GLForm))
                {
                    currentfocus.FindForm()?.OnKeyUp(e);           // reflect to form
                }
                if (!e.Handled)                                    // send to control
                {
                    currentfocus.OnKeyUp(e);
                }
            }
            else
            {
                OnKeyUp(e);
            }
        }