Java by API/javax.swing.event/CaretListener

implements CaretListener

import java.awt.BorderLayout;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.event.CaretEvent;
import javax.swing.event.CaretListener;
public class MainClass {
  public static void main(String args[]) throws Exception {
    JFrame frame = new JFrame("Caret Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JTextArea textArea = new JTextArea();
    JScrollPane scrollPane = new JScrollPane(textArea);
    frame.add(scrollPane, BorderLayout.CENTER);
    CaretListener listener = new CaretListener() {
      public void caretUpdate(CaretEvent caretEvent) {
        System.out.println("dot:"+ caretEvent.getDot());
        System.out.println("mark"+caretEvent.getMark());
      }
    };
    textArea.addCaretListener(listener);
    frame.setSize(250, 150);
    frame.setVisible(true);
  }
}