Using Object-Oriented Patterns - Beginning Java Programming: The Object-Oriented Approach - page 582

continued

interface Window

class NormalWindow
implements Window

class WindowDecorator1
implements Window

class WindowDecorator2
implements Window

Window instanceToDecorate; Window instanceToDecorate;

Multiple, unrelated decorators

figure 12-2

interface Window

abstract class
WindowDecorator
implements Window

class NormalWindow
implements Window

Window instanceToDecorate;

class WindowDecorator1
extends WindowDecorator

class WindowDecorator2
extends WindowDecorator

Decorators share behavior and form class hierarchy.

figure 12-3

interface Window

abstract class
AbstractWindow
implements Window

abstract class
WindowDecorator
implements Window

Window instanceToDecorate;

class ComplexWindow
extends AbstractWindow

class WindowDecorator1
extends WindowDecorator

class WindowDecorator2
extends WindowDecorator

class SimpleWindow
extends AbstractWindow

Both decorators and window classes form class hierarchy, shared behavior in interface.

figure 12-4