UndoStyleFrame.java Source code

Introduction

Here is the source code for UndoStyleFrame.java

Source

import java.awt.event.ActionEvent;

import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JTextPane;
import javax.swing.event.UndoableEditEvent;
import javax.swing.event.UndoableEditListener;
import javax.swing.undo.UndoableEdit;

public class UndoStyleFrame extends JFrame {

    protected UndoAct undoAction = new UndoAct();

    protected RedoAct redoAction = new RedoAct();

    public UndoStyleFrame() {
        super();
        setTitle("UndoStyleFrame");
        JTextPane textPane = new JTextPane();

        textPane.getDocument().addUndoableEditListener(undoAction);
        textPane.getDocument().addUndoableEditListener(redoAction);

        JMenu editMenu = new JMenu("Edit");
        editMenu.add(new JMenuItem(undoAction));
        editMenu.add(new JMenuItem(redoAction));

        JMenuBar menuBar = new JMenuBar();
        menuBar.add(editMenu);

        setJMenuBar(menuBar);

        JPanel buttonPanel = new JPanel();
        buttonPanel.add(new JButton(undoAction));
        buttonPanel.add(new JButton(redoAction));

        getContentPane().add(textPane, "Center");
        getContentPane().add(buttonPanel, "South");
    }

    public class UndoAct extends AbstractAction implements UndoableEditListener {
        private UndoableEdit edit;

        public UndoAct() {
            super("Undo");
            setEnabled(false);
        }

        public void updateEnabled() {
            setEnabled(edit.canUndo());
        }

        public void undoableEditHappened(UndoableEditEvent event) {
            edit = event.getEdit();
            putValue(NAME, edit.getUndoPresentationName());
            updateEnabled();
        }

        public void actionPerformed(ActionEvent ae) {
            edit.undo();
            updateEnabled();
            redoAction.updateEnabled();
        }
    }

    public class RedoAct extends AbstractAction implements UndoableEditListener {
        private UndoableEdit edit;

        public RedoAct() {
            super("Redo");
            setEnabled(false);
        }

        public void updateEnabled() {
            setEnabled(edit.canRedo());
        }

        public void undoableEditHappened(UndoableEditEvent event) {
            edit = event.getEdit();
            putValue(NAME, edit.getRedoPresentationName());
            updateEnabled();
        }

        public void actionPerformed(ActionEvent ae) {
            edit.redo();
            updateEnabled();
            undoAction.updateEnabled();
        }
    }

    public static void main(String[] args) {
        JFrame frame = new UndoStyleFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 300);
        frame.setVisible(true);
    }
}