src/java.desktop/share/classes/javax/swing/MenuElement.java

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package javax.swing;

import java.awt.*;
import java.awt.event.*;

/**
 * Any component that can be placed into a menu should implement this interface.
 * This interface is used by {@code MenuSelectionManager}
 * to handle selection and navigation in menu hierarchies.
 *
 * @author Arnaud Weber
 * @since 1.2
 */

public interface MenuElement {

    /**
     * Processes a mouse event. {@code event} is a {@code MouseEvent} with
     * source being the receiving element's component. {@code path} is the
     * path of the receiving element in the menu hierarchy including the
     * receiving element itself. {@code manager} is the
     * {@code MenuSelectionManager} for the menu hierarchy. This method should
     * process the {@code MouseEvent} and change the menu selection if necessary
     * by using {@code MenuSelectionManager}'s API Note: you do not have to
     * forward the event to sub-components. This is done automatically by the
     * {@code MenuSelectionManager}.
     *
     * @param event a {@code MouseEvent} to be processed
     * @param path the path of the receiving element in the menu hierarchy
     * @param manager the {@code MenuSelectionManager} for the menu hierarchy
     */
    public void processMouseEvent(MouseEvent event, MenuElement[] path, MenuSelectionManager manager);


    /**
     *  Process a key event.
     *
     * @param event a {@code KeyEvent} to be processed
     * @param path the path of the receiving element in the menu hierarchy
     * @param manager the {@code MenuSelectionManager} for the menu hierarchy
     */
    public void processKeyEvent(KeyEvent event, MenuElement[] path, MenuSelectionManager manager);

    /**
     * Call by the {@code MenuSelectionManager} when the {@code MenuElement} is
     * added or removed from the menu selection.
     *
     * @param isIncluded can be used to indicate if this {@code MenuElement} is
     *        active (if it is a menu) or is on the part of the menu path that
     *        changed (if it is a menu item).
     */
    public void menuSelectionChanged(boolean isIncluded);

    /**
     * This method should return an array containing the sub-elements for the
     * receiving menu element.
     *
     * @return an array of {@code MenuElement}s
     */
    public MenuElement[] getSubElements();

    /**
     * This method should return the {@code java.awt.Component} used to paint the
     * receiving element. The returned component will be used to convert events
     * and detect if an event is inside a {@code MenuElement}'s component.
     *
     * @return the {@code Component} value
     */
    public Component getComponent();
}