JavaFX contextmenu not hiding - javafx

Question

I'm trying to show a context menu only when there is something selected in the list view.
So I called hide in its on showing event. However, this is not working. The context menu still shows up. Is this a bug, or not its intended use? Because JavaFX api seems to suggest hide() is suppose to do this.
Anyway this is the code.
ContextMenu menu = new ContextMenu();
menu.setOnShowing(new EventHandler<WindowEvent>() {
#Override
public void handle(final WindowEvent event) {
menu.hide();
}
});

Answer 1

It will probably work if you do
public void handle(final WindowEvent event) {
Platform.runLater(new Runnable() {
#Override
public void run() {
menu.hide();
}
});
}
but that really seems like a horrible hack.
Why not just set the context menu only if something is selected?
final ListView<T> listView = ... ;
final ContextMenu menu = new ContextMenu();
listView.getSelectionModel().selectedItemProperty().addListener(new ChangeListener<T>() {
#Override
public void changed(ObservableValue<? extends T> obs, T oldValue, T newValue) {
if (newValue == null) {
listView.setContextMenu(null);
} else {
listView.setContextMenu(menu);
}
}
});
(obviously replace T with whatever type your ListView is displaying).

Answer 2

private ContextMenu menu; private MenuItem deleteItem;
table.setOnContextMenuRequested(new EventHandler<ContextMenuEvent>() {
#Override
public void handle(ContextMenuEvent event) {
if (table.getSelectionModel().getSelectedIndex() != -1) {
deleteItem.setVisible(true);
deleteItem.setText("delete: " + table.getSelectionModel().getSelectedItem().getName());
contextMenu.show(table, event.getScreenX(), event.getScreenY());
} else {
deleteItem.setVisible(false);
}
event.consume();
}
});
primaryStage.getScene().addEventHandler(MouseEvent.MOUSE_ENTERED, new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent event) { menu.hide(); }});