How to make sure that screen lock really locks and doesn't allow to do anything? I've recently switched from Lenovo A328 (Android 4.4) to Samsung SM-A320F (Android 8.0, not rooted). On Lenovo I had screen lock set to "pattern", and that let me get rid of the misfeature of opening global menu dropdown (don't know what it's called) which allows to do almost anything.

After switch to Samsung I discovered that "pattern" locker no longer protects from this gesture. After pulling down the global menu I can, for instance, turn on WiFi, toggle flash light, change brightness settings, even change sound mode. There are some things I can't do from there, but this doesn't help much: I can even reboot the phone* trying to extract it from my pocket!

I've managed to remove the Phone and Camera shortcuts from the lower left&amp;right corners, but I still can do any other harmful things while lock is on.

So, how can I make sure that screen lock really locks the screen and keys until I trigger its unlocking? Only emergency calls should be possible while locked.



* or whatever it was: holding volUp+volDown+power pressed for several seconds resulted in some sort of restart
The soft reset by key combination is an important requirement for modern smartphones. Most phones now ship with inbuilt batteries. So, the key combination which stimulate a battery pull is definitely needed. I don't see any reason for it to be disabled. Rather you should be more careful and not press those keys for too long.

As for the access to quick toggles from lockscreen, yes that's a problem for some. Android developers just went with a setup which works for most people. Most would want to turn on the flashlight, WiFi, change sound profile; etc without having to unlock the phone first. The flashlight toggle for example is very handy when you need it suddenly.

I don't know of any way to disable access to toggles. Also, so far I haven't had a wrong press on toggles because the phones come with a "Pocket mode" something which blocks the touch functionality when most part of the screen is covered. That said, I do wish that they bring in an option to disable access to all toggles and leave it to the will of the user. It can be useful for some.