import javafx.application.Application;
import javafx.scene.layout.VBox;
import javafx.scene.Scene;
import javafx.stage.Stage;
import javafx.scene.control.Menu;
import javafx.scene.control.MenuBar;
import javafx.scene.control.MenuItem;
import javafx.scene.input.KeyCombination;

public class MenuBarApp extends Application {

    public final static int MENUS_NUM = 3;
    public final static String MENU_STR = "Menu";
    public final static int MENUS_DEPTH = 2;

    static MenuBar menuBar;
    private MenuBarApp.ShortcutGenerator shortcutGenerator = new MenuBarApp.ShortcutGenerator();

    private void init(Stage primaryStage) {
        VBox root = new VBox();
        root.setSpacing(200);
        Scene scene = new Scene(root, 350, 300);
        primaryStage.setScene(scene);
        primaryStage.setTitle("MenuBar Test (" + System.getProperty("javafx.runtime.version") + ")");

        menuBar = new MenuBar();
        root.getChildren().addAll(menuBar);
        reset();
    }

    @Override
    public void start(Stage primaryStage) throws Exception {
        init(primaryStage);
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }

    private void reset() {
        menuBar.getMenus().clear();
        for (int i = 0; i < MENUS_NUM; i++) {
            menuBar.getMenus().add(new MenuBarApp.BarItem(MENU_STR + i, MENUS_DEPTH));
        }
    }

    private class ShortcutGenerator {

        private char c;
        private int mask;
        private String mods[] = new String[]{"ctrl", "alt", "shift"};

        public ShortcutGenerator() {
            c = 'A';
            mask = 0;
        }

        public ShortcutGenerator(char c, int mask) {
            this.c = c;
            this.mask = mask;
        }

        public KeyCombination getShortcut() {
            StringBuilder stringBuilder = new StringBuilder();
            for (int i = 0; i < mods.length; i++) {
                if (((mask >> i) & 1) != 0) {
                    stringBuilder.append(mods[i]).append("+");
                }
            }
            stringBuilder.append(c);

            if (++c > 'Z') {
                c = 'A';
                mask++;
            }

            KeyCombination kk = KeyCombination.keyCombination(stringBuilder.toString());
            return kk;
        }

        @Override
        public MenuBarApp.ShortcutGenerator clone() {
            return new MenuBarApp.ShortcutGenerator(c, mask);
        }
    }

    private class BarItem extends Menu {

        public BarItem(String str, int depth) {
            super(str);
            setStyle("-fx-font-size: 10px;");
            addSubMenu(this, depth - 1);
        }

        private void addSubMenu(MenuItem root, int level) {
            for (int i = 0; i < MENUS_NUM; i++) {
                final MenuItem item;
                if (level > 0) {
                    item = new Menu(root.getText() + " SubMenu " + i);
                } else {
                    item = new MenuItem(root.getText() + " SubMenu Item " + i);
                }
                ((Menu) root).getItems().add(item);
                if (level > 0) {
                    addSubMenu(item, level - 1);
                } else {
                    item.setAccelerator(shortcutGenerator.getShortcut());
                }
            }
        }
    }
}