The other answers mostly use the flags for the setSystemUiVisibility() method in View. However, this API is deprecated since Android 11.
Here are code snippets for showing / hiding system bars with the new API as well as the deprecated one for backward compatibility:
fun Window.hideSystemUI() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
insetsController?.let {
// Default behavior is that if navigation bar is hidden, the system will "steal" touches
// and show it again upon user's touch. We just want the user to be able to show the
// navigation bar by swipe, touches are handled by custom code -> change system bar behavior.
// Alternative to deprecated SYSTEM_UI_FLAG_IMMERSIVE.
it.systemBarsBehavior = WindowInsetsController.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
// make navigation bar translucent (alternative to deprecated
// WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION)
// - do this already in hideSystemUI() so that the bar
// is translucent if user swipes it up
// window.navigationBarColor = getColor(R.color.internal_black_semitransparent_light)
// Finally, hide the system bars, alternative to View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
// and SYSTEM_UI_FLAG_FULLSCREEN.
it.hide(WindowInsets.Type.systemBars())
}
} else {
// Enables regular immersive mode.
// For "lean back" mode, remove SYSTEM_UI_FLAG_IMMERSIVE.
// Or for "sticky immersive," replace it with SYSTEM_UI_FLAG_IMMERSIVE_STICKY
@Suppress("DEPRECATION")
decorView.systemUiVisibility = (
// Do not let system steal touches for showing the navigation bar
View.SYSTEM_UI_FLAG_IMMERSIVE
// Hide the nav bar and status bar
or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
or View.SYSTEM_UI_FLAG_FULLSCREEN
// Keep the app content behind the bars even if user swipes them up
or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN)
// make navbar translucent - do this already in hideSystemUI() so that the bar
// is translucent if user swipes it up
@Suppress("DEPRECATION")
addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION)
}
}
/**
* Shows the system bars and returns back from fullscreen.
* @see hideSystemUI
* @see addSystemUIVisibilityListener
*/
fun Window.showSystemUI() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
// show app content in fullscreen, i. e. behind the bars when they are shown (alternative to
// deprecated View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION and View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN)
setDecorFitsSystemWindows(false)
// finally, show the system bars
insetsController?.show(WindowInsets.Type.systemBars())
} else {
// Shows the system bars by removing all the flags
// except for the ones that make the content appear under the system bars.
@Suppress("DEPRECATION")
decorView.systemUiVisibility = (
View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN)
}
}