New Smoking Law

So can anyone shed any light on the new smoking law? A week or so back I went to Oaks Bottom and went out to the patio area and found it thick with smoke. Nothing, however, compared to yesterday's trip to EastBurn. Seemed like everyone there was smoking. Apparently the law doesn't prohibit smoking on patios, even if they're essentially closed in?

Anyone know what the deal is here?

(Yes, I was on balance in favor of the ban, but this isn't a complaint--just wondering what the law is.)