I am on android 6. Looking for solutiong where I can hide and disable nav bar with soft keys(home, back, recent). On a google page (COSU IMPLEMENTATION) there is a picture comparing pinning and lock task modes, and on the right side we can see options looks like "Home and Recent buttons are hidden", prior to pin mode. But I didnt find any method to do it. I already locked an activity, but still can call nav bar with swipe up. Maybe someone here knows it.
Ok. For everybody who faces. Its impossible to hide navigation bar at all. On a google web page we can see only "HOME AND RECENT BUTTONS ARE HIDDEN", but not the BACK button. So for now with startLockTask() method we can hide everything BUT BACK button. Also disabling status bar it wont be invisible. You can still call it with swipe but there are nothing on it.