Subclassing Graphics2D

One article that I read about testing GUI intensive applications suggested subclassing the Graphics object to provide a textual representation of the calls made on it (http://c2.com/cgi/wiki?ExtremeProgrammingTestingGuiIntensiveApps) my question is, since the Graphics object is propagated by the Swing components that control the rendering of individual controls, how can one substitute a subclass in a coherent manner. One solution I can think of is something like this:

But since you would have to add the boilerplate to every GUI class, that seems a bit clumsy. Is there a better way where the Graphics subclass will automatically get propogated throughout the system?

I don't have an answer to that, but here's a library that contains several subclasses of Graphics2D; maybe its source code provides some clues.

Thanks for the link Ulf. Looking at the tutorials for that library, the two use cases that I see are either constructing the Graphics2D subclass and calling paint(Graphics) directly with the newly created subclass.

Or wrapping the Graphics object inside an overridden paint(Graphics) method:

I guess the first version would be better for the unit testing strategy discussed in the link. That was so simple I don't know why it was escaping me.