San Jose State University | CS 151 - OO Design Section 5 | Fall 2016

Homework 5

Put all work into a directory hw5 of your Git project and push it once a day. Don't put any code into packages. Don't put any code into a src subdirectory.

You will write a Stopwatch (note the lowercase w) class that implements the stopwatch described at this page: https://en.wikipedia.org/wiki/Stopwatch.

Implement a class Stopwatch that implements the MoveableShape interface from chapter 4 of the book. (Note that this code changed recently.)

Here is code to run the stopwatch. Supply the radius on the command line, e.g.

java AnimationTester 400

Also implement a class Dial. You'll need two instances in the StopWatch. For easy testing, make it implement Icon. Here is a tester. (The second parameter is true for including three levels of ticks.)

Provide javadoc for all classes and methods.

Follow the description in the Wiki page for the behavior of the buttons, except that we have no way of holding the second button down for the freeze mode. Instead, make it toggle the freeze mode when the stopwatch is running. That is:

• Top button:
  • Stopwatch running? Make it not run.
  • Stopwatch not running? Make it run.
• Second button:
  • Stopwatch not running? Reset it.
  • Stopwatch running and not frozen? Freeze it.
  • Stopwatch running and frozen? Unfreeze it, resuming actual time.

Hints:

• How to draw those arrows? Unzip the Violet JAR file—it contains the source code. Check out ArrowHead.java.
• How to position those numbers? Look at MultilineText.java in the Violet source code.
• Don't rely on the timer accuracy. Instead, call Instant.now to get the correct time when the stopwatch starts. Whenever move is called and the stopwatch is not frozen, call Instant.now again, compute the difference (Duration.between), convert to nanoseconds, and then into angles.