The Atm.hpp File

// Atm.hpp: This is the header file for the main classes, which 

// reside solely on the ATM side of the application.



#ifndef _ATM_

#define _ATM_



// Files that deal with transactions will often define an ATM_SIDE

// or BANK_SIDE macro to describe which application space they are

// in. The transaction code gets compiled into each application,

// but some methods are only appropriate for one address space or

// the other.







#include <iostream.h>

#include <stdlib.h>

#include ''consts.hpp''



// Forward references

class Transaction;

class TransactionList;

class Network;



// These two pointers provide the path for the Card

// Reader's directory, which simulates where a card is

// inserted, and the ATM's directory, where eaten cards

// are placed. Normally these would be hardware addresses,

// but for our simulation they are going to be directories

// in a file system. A person copies a BankCard file

// into the CardSlots directory to simulate inserting

// a card into the ATM and the ATM removes the file to

// simulate ejecting the card. The ATM moves the file to its

// internal directory to simulate eating a card. The Bank

// Card file is a one-line ASCII file that consists of seven

// numeric characters representing the account number and

// a four-digit PIN number. The bank card itself is the

// same name as the physical card reader's ''name'' data member.

// These two directory strings are assigned in the main driver

// function to the first two command line arguments passed

// in.



extern char CardSlots[];

extern char ATMSlots[];



// The following two constant strings are used for

// portability in simulating ejecting and eating cards.



extern const char* file_delete_format;

extern const char* file_move_format;



// The relationship between the PhysicalCardReader

// and the CardReader is that the CardReader is a

// wrapper class for the PhysicalCardReader. The

// latter is very reusable in that it reads only raw

// data off of a card. The CardReader is specific to

// the domain of ATM and therefore is not reusable. It is

// responsible for distributing the system intelligence

// from the ATM to its pieces (in this case, the CardReader).



class PhysicalCardReader {

     char name[small_string];

public:

   PhysicalCardReader(char* n);

     int readinfo(char* buf);

     void eject_card();

     void eat_card();

};





// The following classes model the physical pieces of the ATM

// class. They include CardReader, Display, Keypad, DepositSlot,

// CashDispenser, and ReceiptPrinter. Of particular interest is

// the SuperKeypad. This class exists solely due to an analysis of

// the behavior of the system. This analysis indicated much

// cohesion between the Keypad and DisplayScreen. Cohesion is one

// metric for determining when two or more classes need

// encapsulation inside of a containing class. It is useful to note

// that a pure data driven analysis methodology would be unable to

// detect such classes since they are motivated by behavior and do

// not exist in the real-world model.

class CardReader {

     PhysicalCardReader cardReader;

   int validcard;

     char account[small_string];

     char pin[small_string];

public:

     CardReader(char* n);

     int read_card();

     int get_account(char*);

     int get_pin(char*);

     void eject_card();

     void eat_card();

};



class Keypad {

      int enabled;

public:

     Keypad();

     void enable();

     void disable();

     char getkey();

};



class DisplayScreen {

public:

     void display_msg(const char*);

};



class SuperKeypad{

     Keypad *keypad;

     DisplayScreen *display;

public:

     SuperKeypad();

     ~SuperKeypad();

     void display_msg(const char*);

     int verify_pin(const char* pin_to_verify);

     Transaction* get_transaction(char* account, char* pin);

};





class CashDispenser{

      int cash_on_hand;

public:

     CashDispenser(int initial_cash);

     int enough_cash(int amount);

     int dispense(int amount);

};



class DepositSlot{

public:

     int retrieve_envelope();

};



class ReceiptPrinter{

public:

     void print(TransactionList* translist);

};





// The BankProxy class is the representative of the Bank class in

// the ATM's address space. It is a wrapper class for the Network,

// which is itself a wrapper for the exact byte-transfer mechanism

// (pipes, in this example).

class BankProxy {

   Network* network;

public:

   BankProxy(Network* n);

   int process(Transaction*);

};





class ATM {

      BankProxy* bank;

      CardReader* cardReader;

      SuperKeypad* superKeypad;

      CashDispenser* CashDispenser;

      DepositSlot* depositSlot;

      ReceiptPrinter* receiptPrinter;

      TransactionList* translist;

public:

     ATM(BankProxy* b, char* name, int cash);

     ~ATM();

     void activate();

     int retrieve_envelope();

     int enough_cash(double amount);

     int dispense_cash(double amount);

};

#endif