Refactoring for Modularity

Large classes, long methods, and various forms of duplicate code are the code smells that often indicate inadequate modularity or abstraction.

Some refactorings for dealing with such smells might be:

• extract method
• extract class
• extract superclass
• extract subclass
• extract interface

In the tic tac toe example, this might take the form of extracting a new makeMove() function from the onMouseClick() function.

Separation of GUI and business logic is another example of this pattern.