A First Look at GUI Applications Part IV: Radio Buttons 1

Contents A.What is Radio Button? B.Metric Converter Example 2

A. What is Radio Button?  Radio buttons allow the user to select one choice from several possible options  The JRadioButton class is used to create radio buttons  JRadioButton constructors: JRadioButton(String text) JRadioButton(String text, boolean selected)  Method isSelected() is for checking selection  An instance of the ButtonGroup class is used to group radio buttons 3

B. Metric Converter Example  Reuse the kilometer converter example  Convert the distance to feet: 1 kilometer = 3281 feet  Convert the distance to inches: 1 kilometer = inches  The new interface is as below: 4

B. Metric Converter Example 1.Enhancing the Design 2.Enhancing the KilometerConverterTest Class 3.Enhancing the KilometerConverter Class 4.Creating the Interface 5

1. Enhancing the Design 6

2. Enhancing the KilometerConverterTest Class 7

3. Enhancing the KilometerConverter Class 8

4. Creating the Interface 4.1. Creating the Activating Class 4.2. Creating the Window 9

4.1. Creating the Activating Class  Class name: MetricConverterProgram  The window’s basic properties: Class name: MetricConverter Title: Metric Converter Size: 400 x

4.2. Creating the Window Generating the Window Creating the Components Grouping the Radio Buttons Converting to Miles Converting to Feet Converting to Inches 11

Generating the Window 12

Creating the Components  Use FlowLayout for this case 13

Grouping the Radio Buttons  Only one radio button is chosen at the same time 14

Converting to Miles 15

Converting to Feet 16

Converting to Inches 17