To redirect the drawing operations to a dumping device, such as a printer or a plotter,  Views calls the member functions of the subclass that implement all the drawing operations. These member functions have to be overloaded to define the drawing operations needed in the various implementations of dump devices.

So that you can immediately “print what you see,” Views provides you with a predefined class, IlvPSDevice.

The IlvPSDevice class lets you print any region of a view to a text file that can be immediately printed on a PostScript printer. Furthermore, all the drawing member functions are implemented to create the PostScript code corresponding to the expected result.