More Inheritance

Abstract

This chapter describes the main object structure in the drawing package, that is, the objects which define each graphical type. These types are lines, circles, arcs, ellipses, rectangles, diamonds, Bezier curves, strings and user-defined shapes. These are implemented as a hierarchy of classes, and so they provide further examples of the important property of inheritance and the need for virtual functions. Full details of these classes can be found in the module DIAGOBJ, although only relevant examples of the classes are given here.