Practice with Model-View-Controller architecture

Goal: To understand how the MVC design pattern is implemented in Java.

Objective: Modify an application to use a Controller.

TemperatureMVC is a simple application that allows the user to raise/lower/set the current temperature.

class diagramThere are four classes in the application: 
TemperatureModel is the data model.
FarenheitGUI is a text field and button GUI.
GraphGUI is a gauge display.
TemperatureApp is the main driver.

The FarenheitGUI class combines both the view and the controller.

Your objective is to decompose the FarenheitGUI class so that the controller is in a separate class.  This will provide a more flexible and testable solution.  In particular it will enable creation of alternate (e.g. non-graphical) user interfaces, and it will facilitate automated testing by being able to drive the application without a GUI.


Directions

1. Download the application source code (zip file).  It is a BlueJ project.  It can be opened in either BlueJ or NetBeans with the Bluej plugin.  Or you can use command line Java.

2. Run the application and perform the Raise, Lower, and Set functions to observe their effect.

3. Create a new class, Controller, that implements ActionListener.  Move the actionPerformed() method from FarenheitGUI to Controller. Add a constructor method. 

4. Modify the main method in the application class to instantiate the controller.   There are a few other minor modifications you must make in order for the application to compile.  (Steps 2 and 3 take only ten minutes once you identify the necessary changes.)

5. Once the program compiles, its runtime behavior should be exactly the same as the original.

6. Create a new class, TestDriver, with a main method that tests all the functions of the controller.  You may simply output the results to the console.  The driver should invoke the raise, lower, and set functions by calling  actionPerformed() directly, and then accessing the model to obtain its current state and printing it.

7.  We have learned that test drivers like the one we created in step 6 are not an effective way to write tests because it relies on a human inspector to verify the printed output.  So convert the driver into a JUnit test, ControllerTest.
(You may omit this step if you haven't used JUnit before and you don't have the 30 minutes it takes to read the tutorial. 

8. Print the source code for the classes and the output from the test driver and staple them in this order:
  1. ControllerTest
  2. TestDriver
  3. Controller
  4. FarenheitGUI
  5. TemperatureApp
  6. Output from tests (Steps 6 and 7)