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Informatics 1 (WS2012/2013)

Website of Prof. Dr. Barne Kleinen, Professor for Media Informatics (Bachelor/Master) at HTW Berlin
HTW Berlin
Programming and Web Technology @ IMI

Exercise 02: Shapes and TicketMachine

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Exercise 02: Shapes and TicketMachine

Pre-lab

What to Bring to Lab

Assignment

**Shapes **

Download the exercise source code from GitHub (you can download the whole exercise02 repository as a zip here) and open up the Figures project.

  1. What do circles, triangles, and squares have in common? Do they have any differences?
  2. Create a circle, a triangle, and two squares. Oops, where is the second square? How can you make both visible on the screen?
  3. Make all four figures have the same color. What did you have to do? Did you make any mistakes doing this?
  4. Now make an interesting picture using these three shapes! Use at least 5 objects. Record what you had to do to get this scene set up. Take a screenshot for your report.
  5. What is wrong with the following constructor?

{ int price = ticketCost; balance = 0; total = 0; }

  1. Download the TicketMachine project from Github (you can download the whole exercise02 repository as a zip here) and open it in BlueJ. Replace the constructor with the constructor from 5 and try it out. Were you right? Record your results in your report.
  2. (For the bored) Okay, so you’ve been programming since before you could talk and this is child’s play. Explore a little deeper – can you make the shapes canvas larger? What happens when a figure hits the wall? How can you figure out where the wall is? Right, this is badly programmed. What would you have to do to get a shape to bounce off the wall? Can you do it?
  3. (For the really bored) Can you make the better-ticket-machine give proper change using Euro coins?
  4. Kara: Go back to the Greenfoot Scenario from last exercise. Look at the source code from Kara01 and KaraWorld01. Do these classes have constructors? If so, can you figure out what they do? (“super” calls the super class constructor).

Writeup

You will be doing your writeup at home. Use the notes that you took in your logbook. Submit your writeup as your post-lab to the Moodle area.

Post-Lab,

AKA What To Turn In

  • a description of what you did during the lab, including a record of how you got BlueJ started and how you produced the pdf
  • a screenshot of your scene. How did you get a screenshot produced?
  • a description of what you tried with the TicketMachine and what you think is wrong with the code given.
  • the names and roles of any collaborators in any parts of the exercise.