Extending ProjectObject

I'm currently writing a module that requires extending the ProjectObject class, and also creating a custom ActivityLog. So basically, I need something on the same level as the NewFileActivityLog class.

Now, there's no issue with creating either of the classes, but the problem comes with the save method of my new ProjectObject class. In ProjectObject.class.php, you have this:

if($this->log_creation) {
            if (instance_of($this, 'File')) {
              $activity_log = new NewFileActivityLog();
            } else {
              $activity_log = new ObjectCreatedActivityLog();
            } // if
            $activity_log->log($this, $this->getCreatedBy());
          } // if

So it looks like you're hacking in the NewFileActivityLog class. It doesn't look like there's a way to implement a custom ActivityLog class without hacking the core, right? Unless I'm missing something.

Also note, that I must extend ProjectObject. I tried extending BaseProjectObject to bypass the parent::save() but then I get a bunch of type errors.

I'd like to be able to bundle this up as a normal module, instead of a module that requires to be hacked in and broken when upgraded.

Thanks!