I am trying to hire a java swing developer, who would most likely work on a java 1.4 based swing app. I have finalized 2-3 people and I would like to give them a one week assignment on Swing. It has to be a really tough one - something that they can't just copy from the internet and something that tests their in-depth knowledge on Swing. I can think of things like split screen windows, and custom UI controls that would involve custom paining. If you were to prepare such an assignment, what would you do? Please share your thoughts/experiences.