JavaFX: Menu items only shown as three dots when in BorderPane

Question

I am trying to learn JavaFX and I've run into a problem with the Menus in my MenuBar. Here is a minimal example:

public void start(Stage mainStage) throws Exception {
    BorderPane root = new BorderPane();
    Scene scene = new Scene(root, 1200, 1000, Color.WHITE);
    MenuBar menuBar = new MenuBar();
    Menu menuFile = new Menu("_File");
    menuBar.getMenus().add(menuFile);
    MenuItem add = new MenuItem("_New");
    menuFile.getItems().add(add);
    root.getChildren().add(menuBar);
    menuBar.prefWidthProperty().bind(mainStage.widthProperty());
    mainStage.setScene(scene);
    mainStage.show();
}

This application starts, but the Menu in the MenuBar is only shown as three dots (...). It does open however when I press ALT+F, so it is there.

From what I understand, a Menu item has no width or similar attribute, so that can't be set. I suspect it has something to do with my root node being a BorderPane, because in every other example I found that works, the root is either a VBox or something else. I seem to get the desired results when I place a Vbox as my root node, and then add the MenuBar and the BorderPane` to the root - but that seems like a strange and uneccesary workaround to me.

So what am I missing here? Is it true that a MenuBar will only ever look like it should in certain containers? What is the difference between a BorderPane and a VBox in this regard? If someone could explain or point me to a part of the documentation that I've missed, I would be very thankful.

Answer 1

You are using a BorderPane and using getChildren().add() to add MenuBar in it, which is incorrect. BorderPane unlike VBox, can't accept any number of children and is divided into 5 specific positions :

• top
• left
• right
• bottom
• center

The children goes into any one of these positions. Please go through the documentation for BorderPane.

You need to add the Menubar to the top of the BorderPane using :

root.setTop(menuBar);