Objectives

• modifying existing code
• inheritance
• polymorphism
• overriding functions

Project Description

Our previous projects have asked you to model a CargoPlane in different ways. There are of course many types of aircraft other than CargoPlanes. In this project, we will model three types of aircraft -- CargoPlane, Commuter and Tanker. Just as a CargoPlane transports Cargo, a Commuter plane transports people and a Tanker transports water to assist in fighting fires.

Since all planes have common attributes and perform common functions, it's natural to design these planes in an inheritance hierarchy with a generic AirCraft class at the top.

For our small project, we have identified these attributes which are common to all aircraft

1. The minimum altitude at which the aircraft flies.
2. The maximum altitude at which the aircraft can fly.
3. The current altitude at which the aircraft is flying.
4. The city to which the aircraft is flying
5. The city from which the aircraft took off for its destination

The actions common to all aircraft are

1. Take off from the current city to the destination
2. Land at the destination
3. Climb to a higher altitude
4. Descend to a lower altitude
5. Report its current status
6. Fly the missions assigned to it

In addition to these common actions, each of our planes will also Load and Unload something (cargo, water, people).

It is NOT necessary to dynamically allocate data members of any class for this project. If you have a working version of project 3 that does not use dynamic memory allocation, that would be a good place to start.

The AirCraft class

1. AirCraft( ) - the AirCraft default constructor
2. AirCraft( const string& startCity, int minAltitude, int maxAltitude) - an alternative AirCraft constructor
3. virtual void TakeOff (const string& whereTo) - begins flying to the destination at the minimum aircraft altitude
4. virtual void Climb( int nrFeet ) -- increases the aircraft's current altitude by the number of feet specified. The aircraft may not fly above its maximum altitude. If attempting to climb too high, the aircraft levels off at its maximum altitude and continues to the destination.
5. virtual void Descend ( int nrFeet ) -- decreases the aircraft's current altitude by the number of feet specified. The aircraft may not fly below its minimum altitude. If attempting to descend too low, the aircraft levels off at its minimum altitude and continues to the destination.
6. virtual void Land ( ) - the aircraft arrives at the destination and sets the current altitude to zero.
7. virtual void Print(ostream& out = cout ) -- Prints the status of the aircraft (min/max altitude, current altitude, city of origin and destination if flying, current city if not flying).
8. virtual ~AirCraft( ) - the AirCraft destructor.
9. virtual void FlyMission ( const string& cmdFile, const string& logFile) = 0; This pure virtual function MUST be implemented in each derived class. This function reads orders from the cmdFile and documents its missions by recording all information in the logFile. Each plane supports the following orders, although the data required and the manner in which the order is carried out may be different for each aircraft type.
   "LOAD", "UNLOAD", "PRINT", "QUIT", "CLIMB", "DESCEND", "LAND", "TAKEOFF"

   A complete description of the command files is given below.

The CargoPlane class

In addition to the public functions defined for the AirCraft class, the CargoPlane class interface is defined by these public functions. It may also be necessary to override and/or use one or more functions from the AirCraft class as part of the CargoPlane interface.

• CargoPlane( ) - the default constructor
• CargoPlane ( double maxWeight, int maxVolume, const string& city, int minAltitude, int maxAltitude) -- another CargoPlane constructor
• int operator+= (const Cargo& cargo) -- "adds" the Cargo container to the plane. Cargo containers which would cause the plane's weight or volume limit to be exceeded should not be loaded. Returns 1 if the cargo was loaded, -1 if not loaded because the weight limit would be exceeded, -2 if the volume limit would be exceeded and -3 if both limits would be exceeded. LoadCargo( ) from project 2 may be used instead of operator+=.
• void operator-= (const string& label) -- "subtracts" the Cargo container with the specified label from the plane. If no cargo container with that label is on the plane, no action is taken and no message is produced.
  You may choose to use the UnLoadCargo() function from project 2, or operator-=(Cargo) from the project 3 extra credit instead of operator-=.
• virtual ~CargoPlane( ) -- CargoPlane's destructor
• virtual void FlyMission ( const string& cmdFile, const string& logFile) -- as described above for the AirCraft class.
• virtual void Print (ostream& out = cout) In addition to the information common to all aircraft, Print() outputs the following information specific to the CargoPlane
  1. Weight Limit - the maximum weight the plane can hold
  2. Weight Loaded - the total number of pounds of cargo loaded on the plane
  3. Weight Remaining - the total number of pounds that can still be loaded on the plane
  4. Volume Limit - the maximum volume of cargo the plane can hold
  5. Volume Loaded - the total space occupied by cargo loaded on the plane
  6. Volume Remaining - the remaining space that can still be loaded on the plane
  7. Current Cargo - a table showing the details of the cargo currently on the plane. If there is no cargo on the plane, an appropriate message should be logged.

The Cargo Class

The Cargo class interface is defined by these public functions:

• Cargo( ) - the Cargo class default constructor
• Cargo (const string& label, int height, int width, int length, double weight) -- another Cargo class constructor
• int GetVolume ( ) -- an accessor which returns the volume of the Cargo container
• double GetWeight( ) -- an accessor which returns the weight of the Cargo container
• const string& GetLabel( ) -- an accessor which returns the label of the Cargo container.
• ~Cargo( ) -- Cargo's destructor

The Commuter Class

The Commuter class interface is defined by these public functions. No other public functions are permitted. It may also be necessary to override and/or use one or more functions from the AirCraft class as part of the Commuter interface.

• Commuter( int maxPersons, const string& city, int minAlt, int maxAlt ) -- the Commuter constructor
• bool Load (const string& person) -- the specified person boards the plane for a pleasant flight to work. Returns true if the person was allowed to board. Returns false if the plane is full.
• virtual void Print(ostream& out = cout) -- in addition to the information printed about every aircraft, this function prints the number of persons on board and a list of passangers. See the sample output for formatting details.
• virtual void Land ( ) - in addition to the actions performed by every aircraft, all persons disembark from the plane.
• virtual ~Commuter( ) -- Commuter's destructor
• virtual void FlyMission ( const string& cmdFile, const string& logFile) -- as described above for the AirCraft class.

The Tanker Class

The Tanker class interface is defined by these public functions. No other public functions are permitted. It may also be necessary to override and/or use one or more functions from the AirCraft class as part of the Tanker interface.

• Tanker( int waterCapacity, const string& baseCity, int minAlt, int maxAlt ) -- Tanker constructor. The waterCapacity is in gallons. The tanker's water tank is initially empty.
• void UnLoad( ) -- drops all the water on the fire
• void Load( ) -- fills the tanker's water tank
• virtual void Print( ostream& out = cout) -- in addition to the information printed about every aircraft, prints the number of gallons of water currently in the tanker if the tanker is flying.
• virtual void Land ( ) -- lands the tanker back at its base city and sets the current altitude to zero.
• virtual ~Tanker( ) -- Tanker's destructor
• virtual void FlyMission ( const string& cmdFile, const string& logFile) -- as described above for the AirCraft class.

Summary of Miscellaneous Project Requirements, Restrictions and Assumptions

Most of these are the same as project 3. New or substantially modified items are indicated with

1. Proj4.cpp will be provided for you. A sample Proj4.cpp is provided in Mr. Frey's public directory. You should copy this file to your directory and use it during your project development and testing. You should submit this file to use submitmake and submitrun.

   This file WILL BE DELETED and REPLACED with a new Proj4.cpp for grading. DO NOT make any changes to this file that might cause compiler/linker errors when it's replaced with the new Proj4.cpp. E.g. do not change the names of functions or add/remove #includes.

2. Sample command files and logfiles may be copied from Mr. Frey's public directory.
3. Limit all input/output to Print() and to FlyMission().
4. Only operator<< for Cargo may be a friend of any class. operator<< may be overloaded for other classes, but not as a friend (there's no need).
5. You may assume that orders found in the command file make sense. For example, the Commuter will not be told to LOAD passengers when it is in flight and the CargoPlane will not be ordered to UNLOAD cargo while in flight.
6. You may assume that the command files exist.
7. You may assume that all input data is valid. In particular this means
   1. The format of the command files will be valid
   2. The values of all data will be valid (eg positive)
   3. The command files will contain no invalid commands
8. All commands must be logged as they are being executed. Some (or all) of the command parameters must also be displayed. See the sample output.
9. No public methods other than those specified are permitted.
10. You may reorder the parameters in any function, but no new parameters may be added, and no parameter may be removed.
11. The return types of the functions may not be changed.
12. The cargo container label may be a multi-word label (eg. Tom's Books).
13. The maximum weight of the plane may not be exceeded. Any cargo container that would cause the weight limit of the plane to be exceeded must not be loaded.
14. The maximum volume of the plane may not be exceeded. Any cargo container that would cause the volume limit of the plane to be exceeded must not be loaded.
15. If a person is not allowed to board the Commuter because the plane is full, a message should be logged.
16. All weight data must be output with 2 decimal points.
17. If a Cargo container cannot be loaded, an appropriate message indicating why it cannot be loaded should be displayed.
18. You may assume that the destination city names are one word (i.e. no spaces).
19. You may assume that commands do not contain spaces
20. Your executable MUST be named Proj4 as that name is used in the testing/grading scripts.

• Your project produces all required output
• The output produced is correct for all test cases
• The output is in an acceptable format (see the sample output section)
• Your program contains all required functions and follows good top-down and OOP design principles.
• Your project correctly uses inheritance and polymorphism. This includes proper base class code reuse.

15% - Coding Standards

More complete documentation for submit and related commands can be found here.

Remember -- if you make any change to your program, no matter how insignificant it may seem, you should recompile and retest your program before submitting it. Even the smallest typo can cause compiler errors and a reduction in your grade.

Avoid unpleasant surprises!
Be sure to use the submitmake and submitrun utilities provided for you to compile, link and run your program after you've submitted it.