Tracing and logging is the “Hello world” of aspect-oriented programming. In these exercises, we will develop some tracing behavior using aspects.

You can reuse the AspectJ project with the figure editor application you have created during the previous track. If you haven't got such a project yet, consult the Invariants: Intro page.

The figure editor includes a log panel for displaying status messages. You can write to this panel through the static method Log.write in package support.

You might notice that the Log class is very simple and contains no references to the GUI part of the application. To find out how it works, follow the advice marker on the write method.

Afterwards, start the track at Exercise 1.