imBMW.iBus.Devices.Real.Bordmonitor.GetItemIndex C# (CSharp) Method

        public static byte GetItemIndex(int count, byte index, bool back = false)
        {
            if (index > 9)
            {
                index -= 0x40;
            }
            // TODO also try 1-3 & 6-8
            var smallscreenOffset = count > 6 ? 0 : 2;
            if (back)
            {
                if (index > 2 && index < smallscreenOffset + 3)
                {
                    index += (byte)(3 + smallscreenOffset);
                }
                smallscreenOffset *= -1;
            }
            return (byte)(index <= 2 ? index : index + smallscreenOffset);
        }