Immersive fullscreen on Android 11 [duplicate]

For compatibility, use WindowCompat and WindowInsetsControllerCompat. You’ll need to upgrade your gradle dependency for androidx.core to at least 1.6.0-alpha03 so that there will be support for setSystemBarsBehavior on SDK < 30. mainContainer is the top-level ConstraintLayout in my activity.

private fun hideSystemUI() {
    WindowCompat.setDecorFitsSystemWindows(window, false)
    WindowInsetsControllerCompat(window, mainContainer).let { controller ->
        controller.hide(WindowInsetsCompat.Type.systemBars())
        controller.systemBarsBehavior = WindowInsetsControllerCompat.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
    }
}

private fun showSystemUI() {
    WindowCompat.setDecorFitsSystemWindows(window, true)
    WindowInsetsControllerCompat(window, mainContainer).show(WindowInsetsCompat.Type.systemBars())
}

You can find out more information about WindowInsets by watching this YouTube video

EDIT:

I didn’t consider display cutouts or in-display cameras in this answer previously. In the app theme style, i added the following to display my content above the cutout (to the top of the screen when in portrait mode):

<item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>

You can read more at this link: Display Cutout