Introduction

A graphical user interface (GUI) presents a user-friendly mechanism for interacting with an application. A GUI (pronounced "GOO-ee") gives an application a distinctive "look" and "feel." Providing different applications with consistent, intuitive user interface components allows users to be somewhat familiar with an application, so that they can learn it more quickly and use it more productively.

Look-and-Feel Observation 11.1

As an example of a GUI, Fig. 11.1 contains an Internet Explorer Web-browser window with some of its GUI components labeled. At the top is a title bar that contains the window's title. Below that is a menu bar containing menus (File, Edit, View, etc.). Below the menu bar is a set of buttons that the user can click to perform tasks in Internet Explorer. Below the buttons is a combo box; the user can type into it the name of a Web site to visit or can click the down arrow at the right side of the box to select from a list of sites previously visited. The menus, buttons and combo box are part of Internet Explorer's GUI. They enable you to interact with Internet Explorer.

Figure 11.1. Internet Explorer window with GUI components.

GUIs are built from GUI components. These are sometimes called controls or widgetsshort for window gadgetsin other languages. A GUI component is an object with which the user interacts via the mouse, the keyboard or another form of input, such as voice recognition. In this chapter and Chapter 22, GUI Components: Part 2, you will learn about many of Java's GUI components. [Note: Several concepts covered in this chapter have already been covered in the optional GUI and Graphics Case Study of Chapters 310. So, some material will be repetitive if you read the case study. You do not need to read the case study to understand this chapter.]