Graphical user interfaces
Exercise 1, Friday 26.10.2007

• Java SE and NetBeans IDE download
• Java 6 API
• Java tutorial UI trail

NetBeans projects consist of several directories and files. Thus pack whole project directory with you (e.g., tar or zip, or all files as they where) when coming to the exercise class. You can bring in the package by storing it, e.g., at cs or USB stick. However you can copy it quickly to the machine at exercise class.

NetBeans and Java are installed in computer class T2/D102 (both Linux and Windows).

Because of the wireless toolkit, NetBeans seem to make an extra 150MB set of directories to you home directory, which doesn't accept it because of disk quotas.

Our administrators gave the following solution:

Start netbeans with a local help directory:

Linux: netbeans --userdir /tmp/own_project_name

Windows: C:/Program Files/netbeans-5.5.1/bin/netbeans.exe -userdir c:\Temp\own_project_name

Then, when creating your new project, you can give the address of the project to your home directory /home/... or network drive in Win. The actual project is less than a MB.

You probably also want to set you executable search path to contain both JDK and NetBeans. In Linux/tcsh:

set path = (/usr/java/latest/bin /usr/local/netbeans-5.5.1/bin/ $path)
rehash

Similarity in bash and command.co

1. Celsius-Fahrenheit-Kelvin -converter

Make a Celsius-Fahrenheit-Kelvin -converter using NetBeans IDE. Follow the instructions at lecture (or Java tutorial) and make an application that converts between Celsius, Fahrenheit, and Kelvin degrees. For each unit, there is a text field showing the temperature, and a button that activates the conversion from that unit to the other units. Show 2 decimal places. Enable (write) tooltips for each component.

Example image:

Example implementation (.class) at examples page. Use Java6 to run.

Hints: String.format (for limiting number of decimals). F = C*1.8 + 32, K = C + 273.15.

2. Adding usability, adjusting accuracy

Make all the following additions:

• Support for pressing ENTER directly in text fields to activate updating of the other units (ActionPerformed).
• Add a slider to adjust the number of decimals (0..5). Whenever slider is adjusted, display accuracy changes (Events, Change, stateChanged).
• Make mouse wheel to adjust the decimal-slider (on the area of whole window) (Hints: Events, MouseWheel, mouseWheelMoved; MouseWheelEvent.getWheelRotation())

Example image:

Consider also the following questions?

• What other UI features could you imagine for the simple converter?
• Now, after you created your application and condidered even more features, how would you change your program structure (methods)?
• In addition to the program structure (methods) you created, what other alternatives there could be?