Apple's concept does not require to open the phone, because the indicator is installed already put in place that is easily seen. Unfortunately it is unclear whether Apple is trying to achieve with this patent. For information, patents related to detecting the presence of water on their phone has been wanted since December of 2006 ago. Finally, after waiting long enough, the patent has been present in the lap of the Cupertino vendor. Granting of this patent is also likely to complicate the already long of various use.
source