A First Look at GUI Applications

Part IV: Radio Buttons

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Contents

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

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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

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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 = 39370 inches The new interface is as below:

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B. Metric Converter Example

1. Enhancing the Design2. Enhancing the KilometerConverterTest Class3. Enhancing the KilometerConverter Class4. Creating the Interface

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1. Enhancing the Design

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2. Enhancing the KilometerConverterTest Class

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3. Enhancing the KilometerConverter Class

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4. Creating the Interface

4.1. Creating the Activating Class4.2. Creating the Window

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4.1. Creating the Activating Class

Class name: MetricConverterProgram The window’s basic properties:

• Class name: MetricConverter• Title: Metric Converter• Size: 400x100

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4.2. Creating the Window

4.2.1. Generating the Window4.2.2. Creating the Components4.2.3. Grouping the Radio Buttons4.2.4. Converting to Miles4.2.5. Converting to Feet4.2.6. Converting to Inches

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4.2.1. Generating the Window

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4.2.2. Creating the Components

Use FlowLayout for this case

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4.2.3. Grouping the Radio Buttons

Only one radio button is chosen at the same time

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4.2.4. Converting to Miles

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4.2.5. Converting to Feet

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4.2.6. Converting to Inches

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