| Represents the clue between the gui and all the folders which want to notify
the statusbar.
We want the folders to be independent from the gui code. So, the folders
should communicate with the Observable, whereas the status observers with the
Observable.
This makes it necessary of course to register as Observer.
This implementation of StatusObserver encapsulates a
Worker , which is more tightly coupled to the gui in Columba.
author: fdietz |