How to disable right click on a menu in javafx - javafx

Question

In javaFX code, a menu can popup by left click or right click. How to disable right click?
public void start(Stage primaryStage)
{
BorderPane root = new BorderPane();
MenuBar menuBar = new MenuBar();
Menu hello = new Menu("hello");
menuBar.getMenus().addAll(hello);
Menu world = new Menu("world");
menuBar.getMenus().addAll(world);
root.setCenter(menuBar);
MenuItem item = new MenuItem("laugh");
hello.getItems().add(item);
Scene scene = new Scene(root, 300, 250);
primaryStage.setTitle("Hello World!");
primaryStage.setScene(scene);
primaryStage.show();
}
When I right click the "hello" menu, it will popup menuitem "laugh".

Answer 1

The basic approach is to register a eventFilter on the MenuBar that consumes the events that should not be delivered to the children.
Doing so manually in your application code:
public class DisableRightClickOpenMenu extends Application {
#Override
public void start(Stage primaryStage) throws Exception {
BorderPane root = new BorderPane();
MenuBar menuBar = new MenuBar();
menuBar.addEventFilter(MouseEvent.MOUSE_PRESSED, ev -> {
if (ev.getButton() == MouseButton.SECONDARY) {
ev.consume();
}
});
Menu hello = new Menu("hello");
menuBar.getMenus().addAll(hello);
Menu world = new Menu("world");
menuBar.getMenus().addAll(world);
root.setCenter(menuBar);
MenuItem item = new MenuItem("laugh");
hello.getItems().add(item);
Scene scene = new Scene(root, 300, 250);
primaryStage.setTitle("Hello World!");
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
If you want this behaviour across all your applications, you can implement a custom menuBarSkin that registers the filter and install the custom skin via a stylesheet.
The skin:
public class ExMenuBarSkin extends MenuBarSkin {
/**
* Instantiates a skin for the given MenuBar. Registers an
* event filter that consumes right mouse press.
*
* #param menuBar
*/
public ExMenuBarSkin(MenuBar menuBar) {
super(menuBar);
menuBar.addEventFilter(MouseEvent.MOUSE_PRESSED, ev -> {
if (ev.getButton() == MouseButton.SECONDARY) {
ev.consume();
}
});
}
}
In your stylesheet (replace with your fully qualified class name):
.menu-bar {
-fx-skin: "de.swingempire.fx.event.ExMenuBarSkin";
}
Its usage (replace the name with your stylesheet file name):
URL uri = getClass().getResource("contextskin.css");
primaryStage.getScene().getStylesheets().add(uri.toExternalForm());

Answer 2

This is usual behavior of menu in many programs. I don't think you can change it. However, you can use some other controls and simulate menu. (Like HBox and Labels).

Answer 3

I agree as far as I know there's no a standard way to do this, but you may want to consider the following workaround.
It is replacing the Menu node with a Menu object composed by an HBox and a Label: an EventHandler is added to the HBox and by checking the mouse button pressed we add/remove on the fly the MenuItem to its parent.
#Override
public void start(final Stage primaryStage) {
final BorderPane root = new BorderPane();
final MenuBar menuBar = new MenuBar();
final Menu menuHello = new Menu();
final Menu menuWorld = new Menu("world");
final MenuItem menuitem = new MenuItem("laugh");
final HBox hbox = new HBox();
menuBar.getMenus().addAll(menuHello, menuWorld);
root.setCenter(menuBar);
hbox.setPrefWidth(30);
hbox.getChildren().add(new Label("hello"));
menuHello.setGraphic(hbox);
menuHello.getItems().add(menuitem);
hbox.addEventHandler(MouseEvent.MOUSE_CLICKED, new EventHandler<MouseEvent>() {
#Override
public void handle(final MouseEvent e) {
if (e.getButton() == MouseButton.SECONDARY) {
System.out.println("Right click");
menuHello.getItems().remove(menuitem);
} else {
System.out.println("Left click");
if (!menuHello.getItems().contains(menuitem)) {
menuHello.getItems().add(menuitem);
menuHello.show(); // The .show method prevent 'losing' the current click }
}
}
});
final Scene scene = new Scene(root, 300, 250);
primaryStage.setTitle("Hello World!");
primaryStage.setScene(scene);
primaryStage.show();
}
This will produce the following result - preview
Note that I've used an HBox just for habit, there's no a particular reason.
While using a workaround like this, my suggestion would be to fill all the Menus with the same 'pattern', such as the HBox + Label combo in my example, and stylize them via css/code (width/height, background/fill/hover... colors etc.) in order to have them as uniform as possible and avoid creating graphic inconsistencies due to have different nodes types in the same menubar.