How to Change the Font of the Text According to User Selection in Java?

The following program demonstrates How to Change the Font of the Text According to User Selection in Java.

You can create a Java application that allows users to change the font name, size, and style of text using control boxes. The following code shows a simple example of such an application using Swing.

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

public class FontSelectorApp extends JFrame {
    private JComboBox<String> fontComboBox;
    private JComboBox<Integer> sizeComboBox;
    private JCheckBox boldCheckBox;
    private JCheckBox italicCheckBox;
    private JTextArea textArea;

    public FontSelectorApp() {
        setTitle("Font Selector");
        setSize(400, 300);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new BorderLayout());

        // Create control boxes
        JPanel controlPanel = new JPanel();
        fontComboBox = new JComboBox<>(GraphicsEnvironment.getLocalGraphicsEnvironment().getAvailableFontFamilyNames());
        sizeComboBox = new JComboBox<>(new Integer[]{12, 14, 16, 18, 20, 24, 28, 32});
        boldCheckBox = new JCheckBox("Bold");
        italicCheckBox = new JCheckBox("Italic");

        controlPanel.add(new JLabel("Font:"));
        controlPanel.add(fontComboBox);
        controlPanel.add(new JLabel("Size:"));
        controlPanel.add(sizeComboBox);
        controlPanel.add(boldCheckBox);
        controlPanel.add(italicCheckBox);

        // Create text area
        textArea = new JTextArea("Sample Text", 5, 30);
        textArea.setFont(new Font("Arial", Font.PLAIN, 16));
        add(controlPanel, BorderLayout.NORTH);
        add(new JScrollPane(textArea), BorderLayout.CENTER);

        // Add action listeners to control boxes
        fontComboBox.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                updateFont();
            }
        });

        sizeComboBox.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                updateFont();
            }
        });

        boldCheckBox.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                updateFont();
            }
        });

        italicCheckBox.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                updateFont();
            }
        });

        setVisible(true);
    }

    private void updateFont() {
        String fontName = fontComboBox.getSelectedItem().toString();
        int fontSize = (int) sizeComboBox.getSelectedItem();
        int fontStyle = Font.PLAIN;
        
        if (boldCheckBox.isSelected()) {
            fontStyle += Font.BOLD;
        }
        if (italicCheckBox.isSelected()) {
            fontStyle += Font.ITALIC;
        }
        
        Font selectedFont = new Font(fontName, fontStyle, fontSize);
        textArea.setFont(selectedFont);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new FontSelectorApp();
            }
        });
    }
}

In this Java Swing application:

At first, we create a FontSelectorApp class that extends JFrame to create the main window.
Inside the constructor:
- Next, we create control boxes for font name, size, and style using JComboBox and JCheckBox components.
- We create a JTextArea where the user can see the text with the selected font.
Then, we add action listeners to the control boxes (fontComboBox, sizeComboBox, boldCheckBox, and italicCheckBox) so that when the user changes their selections, the updateFont method is called to update the font of the text in the textArea.
The updateFont method retrieves the selected font name, size, and style from the control boxes and sets the font of the text area accordingly.
In the main method, we use SwingUtilities.invokeLater to create an instance of the FontSelectorApp on the Swing Event Dispatch Thread.

When you run this application, you can select different font names, sizes, and styles to change the font of the displayed text.

Further Reading