OOA—Analysis and Mission - Programming GPS and OpenStreetMap Applications with Java - page 30

What is a Framework?

In ROAF terminology, a framework supplies laws for yet unspecified appli-
cations. A developer should be free to create his own ROApp, while con-
forming to general standards in order to be compatible with other ROApps.
Technically speaking, the ROAF is a set of classes providing technology and
solutions to code real-world simulations. This common basis afforded by a
real-object application framework reduces programming effort, and helps
to enforce consistency and to increase interoperability.
Later, in the implementation phase, we will see how the idea of a frame-
work functions by looking at the Collection framework to collect spatial
coordinates and the Swing framework for mapping spatial coordinates on
a Cartesian grid. The ROAF observes ROs and propagates information

among them.
Using object-oriented programming, a framework can be coded with a
minimum implementation to get the system up and running before adding
more details in further iterations. The ROAF can be coded around the
RealObject with minimal common attributes of every physical object. GPS
attributes are sucient to trace an object and the framework can imple-
ment the information exchange technology, for example.
Besides being a framework, the ROAF has the potential to create li-
braries in which things can be plugged in. The RealObject is only specified
to be any physical object. Just like a library full of topics on dierent
topics, the RealObject can be extended to become any thing. A developer
might choose to program RealCars and publish this library of different cars
to be used inside the ROAF. An application developer for a race track could
rely on the compatibility of the cars. In object-oriented terms, any subclass
of an RO for any problem domain should function in the framework.

3.7 Candidate Objects

The process from vision to language analysis to a problem statement does
not require programming skills|the exact intention of OOA. Thus, the
customer for a particular software product can and should (for your own
sake|he must!) participate in the initial analysis phase.
The ROAF project was derived from the usual introduction of software
objects and, therefore, the candidate objects are easy to identify. In a
trac simulation the central object is the car, while GPS receiver and
sender are supporting objects. In project terms, a RealCar is a RealObject .
A RealObject has a GPSunit indicating its Position in spatial coordinates.