Android How to Program, 3/e

3.3 Technologies Overview

This section introduces the IDE and Android features you’ll use to build the Tip Calculator app. We assume that you’re already familiar with Java object-oriented programming—if not, we present Java in the book’s appendices. You’ll

• use various Android classes to create objects

• call methods on classes and objects

• define and call your own methods

• use inheritance to create a class that defines the Tip Calculator’s functionality and

• use event handling, anonymous inner classes and interfaces to process the user’s GUI interactions.

3.3.1 Class Activity

Android apps have four types of executable components—activities, services, content providers and broadcast receivers. In this chapter, we’ll discuss activities, which are ...