// RadioButtonTest.java
// Andrew Davison, Jan 2018, ad@fivedots.coe.psu.ac.th

// Creating radio buttons using ButtonGroup and JRadioButton.


import java.awt.*;
import java.awt.event.*;
import javax.swing.*;


public class RadioButtonTest extends JFrame
{
  private JTextField t;
  private Font plainFont, boldFont, italicFont, boldItalicFont;
  private JRadioButton plain, bold, italic, boldItalic;
  private ButtonGroup radioGroup;


  public RadioButtonTest()
  {
    super("RadioButton Test");

    Container c = getContentPane();
    c.setLayout(new FlowLayout());

    t = new JTextField("Watch the font style change", 25);
    c.add(t); 

    // Create radio buttons
    plain = new JRadioButton("Plain", true);
    c.add(plain);
    bold = new JRadioButton("Bold", false);
    c.add(bold);
    italic = new JRadioButton("Italic", false);
    c.add(italic);
    boldItalic = new JRadioButton("Bold/Italic", false);
    c.add(boldItalic);

    // register events
    RadioButtonHandler handler = new RadioButtonHandler();
    plain.addItemListener(handler);
    bold.addItemListener(handler);
    italic.addItemListener(handler);
    boldItalic.addItemListener(handler);

    // create logical relationship between JRadioButtons
    radioGroup = new ButtonGroup();
    radioGroup.add(plain);
    radioGroup.add(bold);
    radioGroup.add(italic);
    radioGroup.add(boldItalic);

    plainFont = new Font("TimesRoman", Font.PLAIN, 14);
    boldFont = new Font("TimesRoman", Font.BOLD, 14);
    italicFont = new Font("TimesRoman", Font.ITALIC, 14);
    boldItalicFont = new Font("TimesRoman", Font.BOLD + Font.ITALIC, 14);
    t.setFont(plainFont);

    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(300, 100);
    setVisible(true);
  }  // end of RadioButtonTest()


  // -----------------------------------------------

  class RadioButtonHandler implements ItemListener
  {
    public void itemStateChanged(ItemEvent e)
    {
      if (e.getStateChange() == ItemEvent.SELECTED) {
        if (e.getSource() == plain) 
          t.setFont(plainFont);
        else if (e.getSource() == bold)
          t.setFont(boldFont);
        else if (e.getSource() == italic) 
          t.setFont(italicFont);
        else if (e.getSource() == boldItalic) 
          t.setFont(boldItalicFont);
        t.repaint();
      }
    }  // end of itemStateChanged()
  }  // end of RadioButtonHandler inner class


  // -----------------------------------------------

  public static void main(String args[])
  {  new RadioButtonTest(); }

}  // end of RadioButtonTest class