// Fig. 11.19: RadioButtonFrame.java
// Creating radio buttons using ButtonGroup and JRadioButton.
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Color;
import java.awt.event.ItemListener;
import java.awt.event.ItemEvent;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JRadioButton;
import javax.swing.ButtonGroup;

public class RadioButtonFrame extends JFrame {

    private JTextField textField; // used to display font changes
    private Font plainFont; // font for plain text
    private Font boldFont; // font for bold text
    private Font italicFont; // font for italic text
    private Font boldItalicFont; // font for bold and italic text
    private JRadioButton plainJRadioButton; // selects plain text
    private JRadioButton boldJRadioButton; // selects bold text
    private JRadioButton italicJRadioButton; // selects italic text
    private JRadioButton boldItalicJRadioButton; // bold and italic
    private ButtonGroup radioGroup; // buttongroup to hold radio buttons //to choose one choise

// RadioButtonFrame constructor adds JRadioButtons to JFrame
    public RadioButtonFrame() {
        super("RadioButton Test");
        setLayout(new FlowLayout()); // set frame layout

        textField = new JTextField("Watch the font style change", 25);//25 digets
        add(textField); // add textField to JFrame

// create radio buttons
        plainJRadioButton = new JRadioButton("Plain", true);
        plainJRadioButton.setForeground(Color.red);
        boldJRadioButton = new JRadioButton("Bold", false);
        boldJRadioButton.setForeground(Color.GREEN);
        italicJRadioButton = new JRadioButton("Italic", false);
        italicJRadioButton.setForeground(Color.BLUE);
        boldItalicJRadioButton = new JRadioButton("Bold/Italic", false);
        boldItalicJRadioButton.setForeground(Color.pink);
        add(plainJRadioButton); // add plain button to JFrame
        add(boldJRadioButton); // add bold button to JFrame
        add(italicJRadioButton); // add italic button to JFrame
        add(boldItalicJRadioButton); // add bold and italic button

// create logical relationship between JRadioButtons
        radioGroup = new ButtonGroup(); // create ButtonGroup
        radioGroup.add(plainJRadioButton); // add plain to group
        radioGroup.add(boldJRadioButton); // add bold to group
        radioGroup.add(italicJRadioButton); // add italic to group
        radioGroup.add(boldItalicJRadioButton); // add bold and italic

// create font objects



        plainFont = new Font("Serif", Font.PLAIN, 14);
        boldFont = new Font("Serif", Font.BOLD, 14);
        italicFont = new Font("Serif", Font.ITALIC, 14);
        boldItalicFont = new Font("Serif", Font.BOLD + Font.ITALIC, 14);
        textField.setFont(plainFont); // set initial font to plain

// register events for JRadioButtons
        plainJRadioButton.addItemListener(
                new RadioButtonHandler(plainFont));
        boldJRadioButton.addItemListener(
                new RadioButtonHandler(boldFont));
        italicJRadioButton.addItemListener(
                new RadioButtonHandler(italicFont));
        boldItalicJRadioButton.addItemListener(
                new RadioButtonHandler(boldItalicFont));
    } // end RadioButtonFrame constructor

// private inner class to handle radio button events // inner= class intro class
    private class RadioButtonHandler implements ItemListener {

        private Font font; // font associated with this listener

        public RadioButtonHandler(Font f) //constuctor beacuse take the same name of class
        {
            font = f; // set the font of this listener
        } // end constructor RadioButtonHandler

// handle radio button events
        public void itemStateChanged(ItemEvent event) {
            textField.setFont(font); // set font of textField
        } // end method itemStateChanged
    } // end private inner class RadioButtonHandler

    // test thr class
    public static void main(String[] arg) {
        RadioButtonFrame buttonFrame = new RadioButtonFrame();
        buttonFrame.setVisible(true);
        buttonFrame.setSize(300, 100);
        buttonFrame.setResizable(false);
    }// end of test class
} // end class RadioButtonFrame