Manipulating Data Using Methods - Java Programming: Comprehensive Concepts and Techniques - page 190

The applet version of the Body Mass Index Calculator now is complete. You
added the import statements, changed the name of the class to BodyMassApplet,
and constructed the applet components. You then entered code for the init()
method. Next, you included the actionPerformed() method to convert the text to
numbers, calculate, and display the answer. Finally, you coded the paint()
method to display the company logo in the Applet Viewer window.
Figure 3-47 shows the applet code in its entirety. Check your own code for
syntax, proper spelling, capitalization, and indentations. Your lines may wrap
differently. When you are confident that everything is correct, you are ready to
save and compile your program.

1 /*
2 Chapter 3: The Body Mass Index Calculator

3 Programmer: J. Starks

4 Date: October 20, 2007

5 Filename: BodyMassApplet.java

6 Purpose: This project calculates the body mass index based

7 on a person's height and weight.

8 */
9
10 import java.applet.*;
11 import java.awt.*;
12 import java.awt.event.*;
13
14 public class BodyMassApplet extends Applet implements ActionListener
15 {
16 //declare variables

17 Image logo; //declare an Image object

18 int inches, pounds;

19 double meters, kilograms, index;

20
21 //construct components

22 Label companyLabel = new Label ( "THE SUN FITNESS CENTER BODY MASS INDEX CALCULATOR" ) ;

23 Label heightLabel = new Label ( "Enter your height to the nearest inch: " ) ;

24 TextField heightField = new TextField ( 10 ) ;

25 Label weightLabel = new Label ( "Enter your weight to the nearest pound: " ) ;

26 TextField weightField = new TextField ( 10 ) ;

27 Button calcButton = new Button ( "Calculate" ) ;

28 Label outputLabel = new Label (

"Click the Calculate button to see your body mass index." ) ;

29
30 public void init ()

31 {

32 setForeground ( Color .red ) ;

33 add ( companyLabel ) ;

34 add ( heightLabel ) ;

35 add ( heightField ) ;

36 add ( weightLabel ) ;

37 add ( weightField ) ;

38 add ( calcButton ) ;

39 calcButton.addActionListener ( this ) ;

40 add ( outputLabel ) ;

41 logo = getImage ( getDocumentBase () , "logo.gif" ) ;

42 }

43
44 public void actionPerformed ( ActionEvent e )

45 {

46
47

inches = Integer .parseInt ( heightField.getText ()) ;

48 pounds = Integer .parseInt ( weightField.getText ()) ;

49 meters = inches / 39.36;

50 kilograms = pounds / 2.2;

51 index = kilograms / Math .pow ( meters,2 ) ;

52 outputLabel.setText ( "YOUR BODY MASS INDEX IS " + Math .round ( index ) + "." ) ;

53 }

54
55 public void paint ( Graphics g )

56 {

57 g.drawImage ( logo,125,160, this ) ;

58 }

59 }

FIGURE 3-47