milhauscz

/**
 * Shows the system bars and returns back from fullscreen.
 * @see hideSystemUI
 * @see addSystemUIVisibilityListener
 */
fun Activity.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)
        window.setDecorFitsSystemWindows(false)

milhauscz

/**
 * Registers a listener which is informed when UI is shown (true) or hidden (false).
 */
fun Window.addSystemUIVisibilityListener(visibilityListener: (Boolean) -> Unit) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
        decorView.setOnApplyWindowInsetsListener { v, insets ->
            val suppliedInsets = v.onApplyWindowInsets(insets)
            // only check for statusBars() and navigationBars(), because captionBar() is not always
            // available and isVisible() could return false, although showSystemUI() had been called:
            visibilityListener(suppliedInsets.isVisible(WindowInsets.Type.statusBars() or WindowInsets.Type.navigationBars()))

milhauscz

/**
 * Hides the system bars and makes the Activity "fullscreen". If this should be the default
 * state it should be called from [Activity.onWindowFocusChanged] if hasFocus is true.
 * It is also recommended to take care of cutout areas. The default behavior is that the app shows
 * in the cutout area in portrait mode if not in fullscreen mode. This can cause "jumping" if the
 * user swipes a system bar to show it. It is recommended to set [WindowManager.LayoutParams.LAYOUT_IN_DISPLAY_CUTOUT_MODE_NEVER],
 * call [showBelowCutout] from [Activity.onCreate]
 * (see [Android Developers article about cutouts](https://developer.android.com/guide/topics/display-cutout#never_render_content_in_the_display_cutout_area)).
 * @see showSystemUI
 * @see addSystemUIVisibilityListener