There is a warning when jumping between MainMenu and GameMenu, and it is not possible to jump from the GameMenu menu to the MainMenu menu.

[huayunliufeng]

My partial code is as follows:
`
@OverRide
protected void initSettings(GameSettings settings) {
settings.setMainMenuEnabled(true);
settings.setGameMenuEnabled(true);
settings.setSceneFactory(new SceneFactory() {
@NotNull
@OverRide
public FXGLMenu newGameMenu() {
return new CustomGameMenu();
}
@NotNull
@OverRide
public FXGLMenu newMainMenu() {
return new CustomMainMenu();
}

    });
}

`

CustomMainMenu：

`
public CustomMainMenu() {
super(MenuType.MAIN_MENU);
}

@Override
public void onCreate() {
    getContentRoot().getChildren().setAll(getMainMenu());
}

private VBox getMainMenu() {
    if (mainMenu == null) {
        Button gameListBtn = new Button("game list");
        Button exitBtn = new Button("exit game");

        mainMenu = getMenuContainer(gameListBtn, exitBtn);
        gameListBtn.setOnAction(MainMenuController.gameListHandler(contentRoot, mainMenu, getGameList()));
        exitBtn.setOnAction(MainMenuController.exitHandler());
    }
    return mainMenu;
}

private VBox getGameList() {
    if (gameList == null) {
        Button game1Btn = new Button("game 1");

        Button game2Btn = new Button("game 2");

        Button game3Btn = new Button("game 3");

        Button goBackBtn = new Button("go back");

        gameList = getMenuContainer(game1Btn, game2Btn, game3Btn, goBackBtn);
        gameList.getStyleClass().addAll("game-list-container");

        game1Btn.setOnAction(MainMenuController.game1Handler(contentRoot, gameList));

        goBackBtn.setOnAction(MainMenuController.goBackHandler(contentRoot, getMainMenu(), gameList));
    }
    return gameList;
}

private VBox getMenuContainer(Node... children) {
    VBox vBox = new VBox(children);
    vBox.setLayoutX(MAIN_MENU_LAYOUT_X);
    vBox.setLayoutY(MAIN_MENU_LAYOUT_Y);
    return vBox;
}

`

CustomGameMenu：

`
public CustomGameMenu() {
super(MenuType.GAME_MENU);
}

@Override
public void onCreate() {
    getContentRoot().getChildren().setAll(getGameMenu());
}

private VBox getGameMenu() {
    if (gameMenu == null) {
        Button newGameBtn = new Button("new game");

        Button continueGameBtn = new Button("continue");

        Button goBackBtn = new Button("go back");

        gameMenu = getMenuContainer(newGameBtn, continueGameBtn, goBackBtn);

        newGameBtn.setOnAction(GameMenuController.newGameHandler());
        continueGameBtn.setOnAction(GameMenuController.continueGameHandler());
        goBackBtn.setOnAction(GameMenuController.goBackHandler());
    }
    return gameMenu;
}

private VBox getMenuContainer(Node... children) {
    VBox vBox = new VBox(children);
    vBox.setLayoutX(GAME_MENU_LAYOUT_X);
    vBox.setLayoutY(GAME_MENU_LAYOUT_Y);
    return vBox;
}

GameMenuController：
private static EventHandler newGameHandler;
private static EventHandler goBackHandler;

public static EventHandler<ActionEvent> newGameHandler() {
    if (newGameHandler == null) {
        newGameHandler = _ -> FXGL.getGameController().startNewGame();
    }
    return newGameHandler;
}

// TODO: Returning to the main menu from this method will result in a warning and will not be successful.
public static EventHandler goBackHandler() {
if (goBackHandler == null) {
goBackHandler = new EventHandler() {
@OverRide
public void handle(ActionEvent event) {
FXGL.getGameController().gotoMainMenu();
}
};
}
return goBackHandler;
}
`

MainMenuController：

`
private static EventHandler gameListHandler;
private static EventHandler exitHandler;

private static EventHandler<ActionEvent> game1Handler;

private static EventHandler<ActionEvent> goBackHandler;

public static EventHandler<ActionEvent> goBackHandler(Pane contentRoot, VBox mainMenu, VBox gameList) {
    if (goBackHandler == null) {
        goBackHandler = _ -> contentRoot.getChildren().setAll(mainMenu);
    }
    return goBackHandler;
}

public static EventHandler<ActionEvent> game1Handler(Pane contentRoot, VBox gameList) {
    if (game1Handler == null) {
        game1Handler = _ -> {
            FXGL.getGameController().gotoGameMenu();
        };
    }
    return game1Handler;
}

public static EventHandler<ActionEvent> gameListHandler(Pane contentRoot, VBox mainMenu, VBox gameList) {
    if (gameListHandler == null) {
        gameListHandler = event -> {
            contentRoot.getChildren().setAll(gameList);
        };
    }
    return gameListHandler;
}

public static EventHandler<ActionEvent> exitHandler() {
    if (exitHandler == null) {
        exitHandler = event -> FXGL.getDialogService().showConfirmationBox(
                "?", b -> {
                    if (b) {
                        FXGL.getGameController().exit();
                    }
                }
        );
    }
    return exitHandler;
}

`

[AlmasB]

Thanks, this behaviour is by design, however, it was the old design and it was never reconsidered. Leave this with me, I'll have a think about the use cases and see if I can update the design and the implementation.

In the meantime, you may wish to add a switch to game scene before you move between menus.

[huayunliufeng]

Thank you, I have resolved the issue through other means.

[AlmasB]

Great that you resolved it, I'm just going to reopen this, so I don't forget to revisit the menu transitions design