Example of using KeyListener

Example to implement KeyListener for Swing UI elements.

Example of using KeyListener

package javamyframe;

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;

/**
 * @web http://java-buddy.blogspot.com/
 */
public class JavaMyFrame extends JFrame 
    implements KeyListener{

    JTextArea textArea;
    JButton buttonClear;
    
    String s = "";
    
    public static void main(String[] args) {
        
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }

    private static void createAndShowGUI() {
        JavaMyFrame myFrame = new JavaMyFrame();

        myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        myFrame.prepareUI();

        myFrame.pack();
        myFrame.setVisible(true);
    }
    
    private void prepareUI(){
        textArea = new JTextArea();
        textArea.setEditable(false);
        textArea.addKeyListener(this);
        JScrollPane panel = new JScrollPane(textArea);
        panel.setPreferredSize(new Dimension(300, 100));
        
        buttonClear = new JButton("Clear");
        buttonClear.addActionListener(anotherActionListener);
        
        getContentPane().add(panel, BorderLayout.CENTER);
        getContentPane().add(buttonClear, BorderLayout.PAGE_END);
    }
    
    ActionListener anotherActionListener = new ActionListener(){

        @Override
        public void actionPerformed(ActionEvent e) {
            s = "";
            textArea.setText(s);
        }
        
    };

    @Override
    public void keyTyped(KeyEvent e) {
        s += e.getKeyChar();
        textArea.setText(s);
    }

    @Override
    public void keyPressed(KeyEvent e) {}

    @Override
    public void keyReleased(KeyEvent e) {}
}

Related: Example of using ActionListener