Chapter  16

Decorator

Most of the time, when you take pictures, you wouldn't think of how you would decorate them later. You take them just because you want to capture the moment. Let's say you have one of them printed later, and then you decide to put it in a nice frame with a type of special glass, so on and so forth. But you can put the same picture in a different frame later if you change your mind. Even though you have changed the frame for the picture, the picture is still the same one without being affected, because you were just adding something to the picture but not changing it.

In object-oriented software, we borrowed a similar idea to add “something” (behavior) to other objects without losing their original flavor—so an augmented object would be an enhanced version of the same class (a framed picture). Any “enhancement” (a frame) can be put on and taken off dynamically. We call this design pattern Decorator, as a decorator object can add to another decorator or the original object to extend its features, leaving the original behaviors intact.