In .Net controls have a
LostFocus event that fires when the control is no longer the active object; tabbing to next control or clicking somewhere else on the application. In Wolfram Language does
EventHandler have a similar event?
"MouseMoved" event cannot be used as this creates all manner of issues in a UI. Is there a hidden equivalent to .Net's
LostFocus? If not can one be replicated without being dependent on the mouse events?