ButtonMenu.java

package net.squiz.matrix.ui;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

public class ButtonMenu extends JToggleButton {

    private JPopupMenu popup;
    private Icon icon;
    private Icon depressedIcon;
    public ButtonMenu(String text, JPopupMenu popup) {
        super(text);
        addActionListener(buttonAction);
        setPopupMenu(popup);
    }

    public ButtonMenu(Icon icon) {
        super(icon);
        addActionListener(buttonAction);
    }

    public ButtonMenu(Icon icon, Icon depressedIcon) {
        super(icon);
        this.icon = icon;
        this.depressedIcon = depressedIcon;
        addActionListener(buttonAction);
    }

    public void setPopupMenu(JPopupMenu newPopup) {
        if (popup != null) {
            popup.removePopupMenuListener(popupListener);
        }
        popup = newPopup;
        if (popup != null) {
            popup.addPopupMenuListener(popupListener);
        }
    }

    protected void showPopup() {
        if (popup != null) {
            popup.show(ButtonMenu.this, 0, getSize().height);
        }
    }

    protected void hidePopup() {
        if (popup != null) {
            popup.setVisible(false);
        }
    }

    private ActionListener buttonAction = new ActionListener() {
        public void actionPerformed(ActionEvent event) {
            if (isSelected()) {
                showPopup();
            if (depressedIcon != null)
                setIcon(depressedIcon);
            } else {
                hidePopup();
                if (depressedIcon != null)
                    setIcon(icon);
            }
        }
    };

    private PopupMenuListener popupListener = new PopupMenuListener() {
        public void popupMenuWillBecomeInvisible(PopupMenuEvent event) {
            if (icon != null)
                setIcon(icon);
            SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    doClick();
                }
            });
        }

        public void popupMenuWillBecomeVisible(PopupMenuEvent event) {}
        public void popupMenuCanceled(PopupMenuEvent event) {}
    };
}