Android why is activity visible after onStop called

I have placed prints in all my activity call backs and what I am seeing is a sequence onStart()->onResume()->onStop() but after onStop is called I see the same activity the main activity displaying. Docs indicate this is called when activity is no longer visible but it looks to me like its getting called when my service is put in the foreground. So which one is guaranteed to be called when it becomes not visible? onStop() was called but my activity is still visible a开发者_开发问答nd user can interact with it.