refactor - create a Contest class hierarchy with common behaviors

[w7sst]

As part of support ARRL DX Contest, it is time to introduce a common class hierarchy for Contests. This was first discussed in Issue #81. This will remove 4 sets of case statements from the code and use virtual functions instead to access contest-specific behaviors.

We are implementing the following class hierarchy. Note that most method behaviors are shown below and may not match actual code.

classDiagram
TMainForm *-- Contest
TMainForm: +TSimContest SimContest
TMainForm: +string Sent Exchange
TMainForm: +RecvExchTypes TExchTypes
TMainForm: +SetContest(TSimContest)
    Contest<|-- Wpx Contest
    Contest<|-- ARRL Field Day Contest
    Contest<|-- CWOPS CWT Contest
    Contest<|-- CQ WW Contest
    Contest*-- MyStation
    Contest: +LoadCallHistory(user_callsign)
  Contest: +PickStation() integer
  Contest: +GetRecvExchTypes() TExchTypes
  Contest: +GetSentExchTypes() TExchTypes
  Contest: +GetExchange(id, out DxStn)

class Station{
  +TExchTypes SentExchTypes
}

Station<|--MyStation
Station<|--DxStation

    class Wpx Contest{
       +LoadCallHistory(user_callsign)
       +GetExchange(id, out DxStn)
    }
    class ARRL Field Day Contest{
       +LoadCallHistory(user_callsign)
       +GetExchange(id, out DxStn)
    }
    class CWOPS CWT Contest{
       +LoadCallHistory(user_callsign)
       +GetExchange(id, out DxStn)
    }
    class CQ WW Contest{
       +LoadCallHistory(user_callsign)
       +GetRecvExchTypes() TExchTypes
       +GetSentExchTypes() TExchTypes
       +GetExchange(id, out DxStn)
    }

Loading

For additional information, see the Class Hierarchy design discussion #81 .