The decorator pattern, also known as the wrapper pattern, is when you wrap an object within another object, thus providing a means of enhancing or overriding certain behavior. The wrapper object will delegate any incoming method calls to the original object, unless it defines a new method to enhance or replace the original object’s behavior. By using the decorator pattern, you can dynamically create as many decorated objects as you want, each enhancing the behavior of the original object in a unique way — and all without mutating the original object. In this manner, you can effectively add, remove, or extend behaviors at runtime.
In this snippet we have a class hierarchy with a SimpleMessage at the top. The SimpleMessage class has a constructor that accepts a content string as well as two methods: GetMessage; and, PrintMessage. Down the hierarchy we have three subclasses: ExcitedMessage; QuizzicalMessage; and, ExcitedAndQuizzicalMessage. The only difference in the subclasses is that they override the SimpleMessage constructor to change the content string and append various exclamations. When we instantiate various message objects, using the same content string, and iterate over them, each has their own unique output.
I am a fully qualified painter and decorator and pride myself on offering a hassle free and affordable service where the customer’s needs always take priority, as do excellent quality workmanship and operating to modern standards. We are confident that we can meet all your requirements on your next painting and decorating project and also exceed your expectations when it comes to quality and affordable painters and decorators in Crook.
Component Interface: The component interface is an abstraction describing the behaviors of the components that you will eventually use in your program. Any objects that will use these components will do so through the interface, meaning that they are principally concerned with the abstraction (not the actual object). This is what allows both objects and wrapped objects to be considered to be the same type.
Moreover, the use of language is only an abstraction for a color equivalent. The word "red", for example, can cover a wide range of variations from the pure red of the visible spectrum of light. There is not a formalized register of different colors in the way that there is agreement on different notes in music, such as F or C♯. For a painter, color is not simply divided into basic (primary) and derived (complementary or mixed) colors (like red, blue, green, brown, etc.).