What a SMART kitty!

I have a thing (don't know if there is a name).........it's a metal pin on a chain. You drill a hole for the pin through the sliding glass door frame where you want the door to stop. Got it at Home Depot I believe.
Mine is actually at the 'all-the-way-shut' point, because my hubby used to work nightshifts, and I wanted the security.
I would imagine you could have more than one place(s) to stop it at.