Mastering Delphi Programming: A Complete Reference Guide

Composite

Sometimes, we have to work with data that is organized into a tree structure. There is an entry point, an object of some class N, which owns other objects of the same class N or objects of class L. We call this entry point a root, class N, an inner node, and L, a leaf.

When we perform some operation on such compound data, it is helpful if we can treat all objects the same. In other words, we don't want to distinguish between a root, an inner node, and a leaf. The composite pattern allows us to treat all types of components the same.

Imagine an irrigation system. At some point, it is connected to a water supply. The irrigation system can then split into multiple branches that end in different kinds of water dispensers. We don't care ...