import java.awt.AWTEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JComponent;
import javax.swing.JMenu;
import javax.swing.UIDefaults;
import javax.swing.UIManager;
import javax.swing.border.Border;
import javax.swing.border.BevelBorder;
import javax.swing.border.CompoundBorder;
import javax.swing.border.EmptyBorder;
import javax.swing.plaf.ComponentUI;
import javax.swing.plaf.basic.BasicMenuUI;

public class RolloverMenu extends JMenu {
    private UIDefaults defaults = UIManager.getLookAndFeelDefaults();
    private boolean selected;

    private Border rolloverBorder;
    private Border raisedBorder;
    private Border loweredBorder;

    public RolloverMenu(String s) {
        super(s);
        setUI(RolloverMenuUI.createUI(this));
            
        rolloverBorder = createRolloverBorder();
        raisedBorder = createRaisedBevelBorder();
        loweredBorder = createLoweredBevelBorder();

        setBorder(createRolloverBorder());

        enableEvents(AWTEvent.MOUSE_EVENT_MASK);
    }
        
    public void processMouseEvent(MouseEvent event) {
        if (contains(event.getX(), event.getY())) {
            if (selected) {
                setBorder(loweredBorder);
            } else {
                setBorder(raisedBorder);
            }
        } else {
            if (!selected) {
                setBorder(rolloverBorder);
            }
        }
        
        super.processMouseEvent(event);
    }

    public void fireMenuSelected() {
        selected = true;
        setBorder(loweredBorder);
        super.fireMenuSelected();
    }

    public void fireMenuCanceled() {
        deselected();
        super.fireMenuCanceled();
    }

    public void fireMenuDeselected() {
        deselected();
        super.fireMenuDeselected();
    }

    private void deselected() {
        selected = false;
        setBorder(rolloverBorder);
    }

    private Border createRolloverBorder() {
        return new CompoundBorder(new EmptyBorder(2, 2, 3, 2),
                                  new EmptyBorder(3, 3, 3, 3));
    }

    private Border createLoweredBevelBorder() {
        return new CompoundBorder(new BevelBorder(BevelBorder.LOWERED,
                                                  defaults.getColor("Button.light"),
                                                  defaults.getColor("Button.highlight"),
                                                  defaults.getColor("Button.shadow"),
                                                  defaults.getColor("Button.darkShadow")),
                                  new EmptyBorder(3, 3, 3, 3));
    }

    private Border createRaisedBevelBorder() {
        return new CompoundBorder(new BevelBorder(BevelBorder.RAISED,
                                                  defaults.getColor("Button.light"),
                                                  defaults.getColor("Button.highlight"),
                                                  defaults.getColor("Button.shadow"),
                                                  defaults.getColor("Button.darkShadow")),
                                  new EmptyBorder(3, 3, 3, 3));
    }

    public static class RolloverMenuUI extends BasicMenuUI {
        public static ComponentUI createUI(JComponent c) {
            return new RolloverMenuUI();
        }

        protected void installDefaults() {
            super.installDefaults();
            selectionBackground = UIManager.getLookAndFeelDefaults().getColor("Button.background");
        }        
    }
}