Main.java Source code

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Here is the source code for Main.java

Source

import java.awt.event.ActionEvent;

import javax.swing.AbstractAction;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.event.UndoableEditEvent;
import javax.swing.event.UndoableEditListener;
import javax.swing.text.Document;
import javax.swing.text.JTextComponent;
import javax.swing.undo.CannotUndoException;
import javax.swing.undo.UndoManager;

public class Main {
    public static void main(String[] argv) {
        JTextComponent textcomp = new JTextArea();
        final UndoManager undo = new UndoManager();
        Document doc = textcomp.getDocument();

        doc.addUndoableEditListener(new UndoableEditListener() {
            public void undoableEditHappened(UndoableEditEvent evt) {
                undo.addEdit(evt.getEdit());
            }
        });

        textcomp.getActionMap().put("Undo", new AbstractAction("Undo") {
            public void actionPerformed(ActionEvent evt) {
                try {
                    if (undo.canUndo()) {
                        undo.undo();
                    }
                } catch (CannotUndoException e) {
                }
            }
        });

        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(new JScrollPane(textcomp));
        frame.setSize(380, 320);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
}