CS 1713/1711 Introduction to Computer Science Assignment 2

CS 1713 Major Assignment 2:
The Vendomatic 2000 [Due November 2, 1999]

This is one of four major individual assignments that you are required to complete in this class. You MUST design and code this project on your own. You can ask for debugging help, particularly from the tutors, TA or instructor, but this project is to be your own work. The project relies builds on Project 1. You should start with the solution provided for Project 1.

The Vendomatic 1000 was an paralleled success---the chilled beverage machine has become a favorite meeting place in offices across the country. Vendomatic Inc. has just realized that people might actually pay money for dispensed chilled beverages. You have been assigned to design, implement and test the Vendomatic 2000, a new machine based on the Vendomatic 1000 that charges money for dispensed chilled beverages.

The Vendomatic 2000 waits for the user to press a button (myAskForBeverage). If the user presses the button (rather than clearing it), the Vendomatic 2000 pops up a window asking the customer to enter a specified amount of money (the cost of the item). If the customer enters at least the required amount, the Vendomatic 2000 displays the amount of change, and dispenses the drink. If the customer does not enter enough money, the Vendomatic 2000 refunds the entire amount and does not dispense a drink. In either case, the Vendomatic 2000 clears the button.

In part I you will implement a HandleMoney class that takes care of prompting the user and making change. In part II, you will incorporate the HandleMoney class into the vending machine. In part III, you will put a loop into the Operate method to continue until all drinks have been dispensed.

Part I: Building the interface for taking money (10 points)
Create a new standalone project called HandleMoneyMainTest. Implement the HandleMoney class as follows:
The HandleMoney class extends SimpleGUI for the purpose of using the getDouble function. It keeps track of the cost of the item and the total amount of money that it has taken in for all transaction so far. The constructor for HandleMoney initializes the cost of the item and sets the total amount of money so far to zero. (Don't forget to call super() as the first line in the constructor so that the SimpleGUI is initialized.)
In addition to the usual accessor methods, HandleMoney has a modifier method called takeMoney that pops up a window prompting the user to enter the amount of the drink. This window will appear when your program calls the getDouble function described on page 81 of your text. If the user has entered more than the cost of the item, display the amount of change and update the total money taken in so far. If the user entered less than the cost of the item, display a message indicating that there was not enough money. Do not update the total money in this case. The HandleMoney method should return a boolean value indicating whether or not to dispense a drink.
Add test calls to the HandleMoneyMainTest to test this class. Follow the pattern given in the solution for Project 1 for testing the VendingButton class. At a minimum, you must call all of the methods in takeMoney and output the results in a legible format.
Part II: Adding the money changer to the vending machine (10 points).
- Setting up the skeleton:
  - Create a new standalone project called Vendomatic2000Main.
  - Add the VendingButton and BottleDispenser classes from Project 1.
  - Copy the Vendomatic1000.java file into the same directory and rename it Vendomatic2000.java. Rename the class to be Vendomatic2000.java in the file as well and add this to the project.
  - Build and run the project before going on.
  Note: Your final project should contain the following .java files:
  - Vendomatic2000Main.java (new project)
  - VendingButton.java (from project 1)
  - BottleDispenser.java (from project 1)
  - Vendomatic2000.java (the Vendomatic1000.java with modifications.
  - HandleMoney.java (from part I of project 2)
  It is a good idea to copy the files to the Vendomatic2000Main directory and then include them in the project. You can move them to a different machine by copying the entire directory, thus having all the code for each class to refer to.
- Adding the money handling:
  The Vendomatic 2000 deals with money through an object of type HandleMoney
  - Add the HandleMoney class designed from part I to the Vendomatic2000Main project. Build and run the project before going on.
  - Modify the Vendomatic2000 class so that in addition to the VendingButton and the BottleDispenser, it has a field of type HandleMoney called myMoney.
  - Add an itemcost parameter to the Vendomatic2000 constructor that gives the cost of an bottle. Make other modifications to the constructor as appropriate. Build and run.
  - Implement the money handling for the Vendomatic 2000 as described at the beginning of the handout by modifying Operate appropriately. Build and run.
- Testing:
  Add 5 test scenarios to the Vendomatic2000Main program to test the modifications that you have made to the Vendomatic2000 class. Follow the pattern of the solution for part I.
Part III: Adding a loop for continuous operation (10 points).
Add a loop to the Operate method of the Vendomatic2000 class so that it will process multiple user transactions. The Vendomatic2000 waits for user button presses until the machine is empty. At that point it returns from Operate. Include 5 additional test scenarios in Vendomatic2000Main to test the looping mechanism.

Last revision: October 29, 1999 at 11:15 am.