SystemServices.kt

private val keyguardManager: KeyguardManager

init {
    keyguardManager = context.getSystemService(Context.KEYGUARD_SERVICE) as KeyguardManager
}

fun isDeviceSecure(): Boolean = if (hasMarshmallow()) keyguardManager.isDeviceSecure else keyguardManager.isKeyguardSecure

// Used to block application if no lock screen is setup.
fun showDeviceSecurityAlert(): AlertDialog {
    return AlertDialog.Builder(context)
            .setTitle(R.string.lock_title)
            .setMessage(R.string.lock_body)
            .setPositiveButton(R.string.lock_settings, { _, _ -> context.openLockScreenSettings() })
            .setNegativeButton(R.string.lock_exit, { _, _ -> System.exit(0) })
            .setCancelable(BuildConfig.DEBUG)
            .show()
}

fun hasMarshmallow() = Build.VERSION.SDK_INT >= Build.VERSION_CODES.M