code sample in javadoc refers to renamed PopupMenu and use old signature of setOnShowing(Runnable run)


See:

final PopupMenu popupMenu = new PopupMenu();
popupMenu.setOnShowing(new Runnable() {
    public void run() {
        System.out.println("showing");
    }
});
popupMenu.setOnShown(new Runnable() {
    public void run() {
        System.out.println("shown");
    }
});

MenuItem item1 = new MenuItem("About");
item1.setOnAction(new EventHandler() {
    public void handle(ActionEvent e) {
        System.out.println("About");
    }
});
MenuItem item2 = new MenuItem("Preferences");
item2.setOnAction(new EventHandler() {
    public void handle(ActionEvent e) {
        System.out.println("Preferences");
    }
});
popupMenu.getItems().addAll(item1, item2);
}

final Button button = new Button("Click me");
button.setOnAction(new EventHandler() {
    public void handle(ActionEvent e) {
        popupMenu.show(button, HPos.CENTER, VPos.BOTTOM, 0, 0);
    }
});
Group root = (Group) scene.getRoot();
root.getChildren().add(button);