How to hide the soft-key bar on Android phone?

Question

　

When my app starts, I'd like to hide the soft keys bar (in red rectangle) to have a larger screen.

1. How can I hide it?

2. Do I need to show the bar purposely when the app quits? Or it will restore itself automatically after the app quits?

Android 4.1, with no hardware keys on phone front.

Answer 1

I know its late but it is the right answer so what you are trying to do is what called immersive mode. for (API 19)

check out: https://developer.android.com/training/system-ui/immersive.html

The code that you were asking for is:

@Override
public void onWindowFocusChanged(boolean hasFocus) {
    super.onWindowFocusChanged(hasFocus);
    if (hasFocus) {
        getWindow().getDecorView().setSystemUiVisibility(
                View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                        | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                        | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                        | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                        | View.SYSTEM_UI_FLAG_FULLSCREEN
                        | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
    }
}