Easier done then said.Ahhh, I see your predicament. What you're after is a safety toggle latch.
You probably won't find the exact one as shown, but there are certainly alternatives. It just means hours of browsing through toggle manufacturers' online catalogues.
It's more than just safety though. I believe that would mean it can't accidentally come unlatched by catching on your cardigan.Yup, hence 'safety', which means the latch features a....err...latching mechanism.