Software Engineering Question

Assignment 2 – class design Due: 1 May The front door to an apartment building has a combined code-lock and telephone, see Figure 1, that works in the following way: • To unlock the door, press ‘C’ and enter the correct 4-key code. The door is unlocked for 30 seconds, during which pressed keys are ignored. If during the entering it takes longer than 10 seconds between two different keys, the lock-phone is reseted. • To phone an apartment, enter the correct 4-key apartment number and then press ‘C’. If during the entering it takes longer than 10 seconds between two different keys, the lock-phone is reseted. The phone call ends when either the lock-phone user press ‘R’ or the apartment user ends the call, or if nothing happens for 30 seconds. During a phone call, pressed keys (excepts ‘R’) are ignored. Figure 1. The code-lock and telephone. Usage scenarios is specified in the use cases in Figure 2 below, and the use case diagram in Figure 3 (the phone and lock is named PL). Figure 2. Use case scenerio. Figure 3. Use case diagram. Assignment: Define a class to represent the lock and phone (only one class is needed, and you do not have to define any class diagram). Define attributes and public methods (you do not have to model parameters and types of the methods). Enhance the use case diagram in a better informative way.