Create JToggleButtonMenuItem from JToggleButton in Java

/*/*from   w  ww  .  j a  va2 s .c om*/
Definitive Guide to Swing for Java 2, Second Edition
By John Zukowski     
ISBN: 1-893115-78-X
Publisher: APress
*/

import java.awt.Color;
import java.awt.Component;
import java.awt.Event;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.MouseEvent;

import javax.swing.Action;
import javax.swing.ButtonGroup;
import javax.swing.ButtonModel;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JRadioButtonMenuItem;
import javax.swing.JToggleButton;
import javax.swing.KeyStroke;
import javax.swing.MenuElement;
import javax.swing.MenuSelectionManager;
import javax.swing.event.MouseInputListener;

public class Main {
  public static void main(String args[]) {
    JFrame frame = new JFrame("JToggleButtonMenuItem Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JMenuBar bar = new JMenuBar();
    JMenu file = new JMenu("File");
    file.setMnemonic('f');
    JMenuItem newItem = new JMenuItem("New", 'N');
    file.add(newItem);
    JMenuItem openItem = new JMenuItem("Open", 'O');
    file.add(openItem);
    JMenuItem closeItem = new JMenuItem("Close", 'C');
    file.add(closeItem);
    file.addSeparator();
    JMenuItem saveItem = new JMenuItem("Save", 'S');
    file.add(saveItem);
    file.addSeparator();
    JMenuItem exitItem = new JMenuItem("Exit", 'X');
    file.add(exitItem);
    bar.add(file);
    JMenu edit = new JMenu("Edit");
    JMenuItem cutItem = new JMenuItem("Cut", 'T');
    cutItem.setAccelerator(KeyStroke.getKeyStroke('X', Event.CTRL_MASK));
    edit.add(cutItem);
    JMenuItem copyItem = new JMenuItem("Copy", 'C');
    copyItem.setAccelerator(KeyStroke.getKeyStroke('C', Event.CTRL_MASK));
    edit.add(copyItem);
    JMenuItem pasteItem = new JMenuItem("Paste", 'P');
    pasteItem.setAccelerator(KeyStroke.getKeyStroke('V', Event.CTRL_MASK));
    pasteItem.setEnabled(false);
    edit.add(pasteItem);
    edit.addSeparator();
    JMenuItem findItem = new JMenuItem("Find", 'F');
    findItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F3, 0));
    edit.add(findItem);
    edit.setMnemonic('e');
    Icon atIcon = new ImageIcon("at.gif");
    JMenu findOptions = new JMenu("Options");
    findOptions.setIcon(atIcon);
    findOptions.setMnemonic('O');
    ButtonGroup directionGroup = new ButtonGroup();
    JRadioButtonMenuItem forward = new JRadioButtonMenuItem("Forward", true);
    findOptions.add(forward);
    directionGroup.add(forward);
    JRadioButtonMenuItem backward = new JRadioButtonMenuItem("Backward");
    findOptions.add(backward);
    directionGroup.add(backward);
    findOptions.addSeparator();
    JCheckBoxMenuItem caseItem = new JCheckBoxMenuItem("Case Insensitive");
    findOptions.add(caseItem);
    edit.add(findOptions);
    JToggleButtonMenuItem toggleItem = new JToggleButtonMenuItem(
        "Ballon Help");
    toggleItem.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        System.out.println("Selected");
      }
    });
    edit.add(toggleItem);
    bar.add(edit);
    frame.setJMenuBar(bar);
    frame.setSize(350, 250);
    frame.setVisible(true);
  }
}

class JToggleButtonMenuItem extends JToggleButton implements MenuElement {
  Color savedForeground = null;

  private static MenuElement NO_SUB_ELEMENTS[] = new MenuElement[0];

  public JToggleButtonMenuItem() {
    init();
  }

  public JToggleButtonMenuItem(String label) {
    super(label);
    init();
  }

  public JToggleButtonMenuItem(String label, Icon icon) {
    super(label, icon);
    init();
  }

  public JToggleButtonMenuItem(Action action) {
    super(action);
    init();
  }

  private void init() {
    updateUI();
    setRequestFocusEnabled(false);
    // Borrows heavily from BasicMenuUI
    MouseInputListener mouseInputListener = new MouseInputListener() {
      // If mouse released over this menu item, activate it
      public void mouseReleased(MouseEvent mouseEvent) {
        MenuSelectionManager menuSelectionManager = MenuSelectionManager
            .defaultManager();
        Point point = mouseEvent.getPoint();
        if ((point.x >= 0) && (point.x < getWidth()) && (point.y >= 0)
            && (point.y < getHeight())) {
          menuSelectionManager.clearSelectedPath();
          // component automatically handles "selection" at this point
          // doClick(0); // not necessary
        } else {
          menuSelectionManager.processMouseEvent(mouseEvent);
        }
      }

      // If mouse moves over menu item, add to selection path, so it
      // becomes armed
      public void mouseEntered(MouseEvent mouseEvent) {
        MenuSelectionManager menuSelectionManager = MenuSelectionManager
            .defaultManager();
        menuSelectionManager.setSelectedPath(getPath());
      }

      // When mouse moves away from menu item, disaarm it and select
      // something else
      public void mouseExited(MouseEvent mouseEvent) {
        MenuSelectionManager menuSelectionManager = MenuSelectionManager
            .defaultManager();
        MenuElement path[] = menuSelectionManager.getSelectedPath();
        if (path.length > 1) {
          MenuElement newPath[] = new MenuElement[path.length - 1];
          for (int i = 0, c = path.length - 1; i < c; i++) {
            newPath[i] = path[i];
          }
          menuSelectionManager.setSelectedPath(newPath);
        }
      }

      // Pass along drag events
      public void mouseDragged(MouseEvent mouseEvent) {
        MenuSelectionManager.defaultManager().processMouseEvent(
            mouseEvent);
      }

      public void mouseClicked(MouseEvent mouseEvent) {
      }

      public void mousePressed(MouseEvent mouseEvent) {
      }

      public void mouseMoved(MouseEvent mouseEvent) {
      }
    };
    addMouseListener(mouseInputListener);
    addMouseMotionListener(mouseInputListener);
  }

  // MenuElement methods
  public Component getComponent() {
    return this;
  }

  public MenuElement[] getSubElements() {
    // no subelements
    return NO_SUB_ELEMENTS;
  }

  public void menuSelectionChanged(boolean isIncluded) {
    ButtonModel model = getModel();
    // only change armed state if different
    if (model.isArmed() != isIncluded) {
      model.setArmed(isIncluded);
    }

    if (isIncluded) {
      savedForeground = getForeground();
      if (!savedForeground.equals(Color.blue)) {
        setForeground(Color.blue);
      } else {
        // In case foreground blue, use something different
        setForeground(Color.red);
      }
    } else {
      setForeground(savedForeground);
      // if null, get foreground from installed look and feel
      if (savedForeground == null) {
        updateUI();
      }
    }
  }

  public void processKeyEvent(KeyEvent keyEvent, MenuElement path[],
      MenuSelectionManager manager) {
    // If user presses space while menu item armed, select it
    if (getModel().isArmed()) {
      int keyChar = keyEvent.getKeyChar();
      if (keyChar == KeyEvent.VK_SPACE) {
        manager.clearSelectedPath();
        doClick(0); // inherited from AbstractButton
      }
    }
  }

  public void processMouseEvent(MouseEvent mouseEvent, MenuElement path[],
      MenuSelectionManager manager) {
    // For when mouse dragged over menu and button released
    if (mouseEvent.getID() == MouseEvent.MOUSE_RELEASED) {
      manager.clearSelectedPath();
      doClick(0); // inherited from AbstractButton
    }
  }

  // Borrows heavily from BasicMenuItemUI.getPath()
  private MenuElement[] getPath() {
    MenuSelectionManager menuSelectionManager = MenuSelectionManager
        .defaultManager();
    MenuElement oldPath[] = menuSelectionManager.getSelectedPath();
    MenuElement newPath[];
    int oldPathLength = oldPath.length;
    if (oldPathLength == 0)
      return new MenuElement[0];
    Component parent = getParent();
    if (oldPath[oldPathLength - 1].getComponent() == parent) {
      // Going deeper under the parent menu
      newPath = new MenuElement[oldPathLength + 1];
      System.arraycopy(oldPath, 0, newPath, 0, oldPathLength);
      newPath[oldPathLength] = this;
    } else {
      // Sibling/child menu item currently selected
      int newPathPosition;
      for (newPathPosition = oldPath.length - 1; newPathPosition >= 0; newPathPosition--) {
        if (oldPath[newPathPosition].getComponent() == parent) {
          break;
        }
      }
      newPath = new MenuElement[newPathPosition + 2];
      System.arraycopy(oldPath, 0, newPath, 0, newPathPosition + 1);
      newPath[newPathPosition + 1] = this;
    }
    return newPath;
  }
}