By executing the following code and following the steps:
1- Right click on red panel -> context menu is shown (OK)
2- Left click into the grey area -> context menu is hidden (OK)
3- Right click on red panel -> context menu is not shown again (NOT OK)
It should show the context menu.

Note: Value of showingProperty is printed out.


import javafx.application.Platform;
import javafx.embed.swing.JFXPanel;
import javafx.scene.Scene;
import javafx.scene.control.ContextMenu;
import javafx.scene.control.MenuItem;
import javafx.scene.layout.StackPane;

import javax.swing.*;
import java.awt.*;

public class ContextMenuTest {

    public static void main(String[] args) {

        javax.swing.SwingUtilities.invokeLater(() -> {
            ContextMenuTest swingView = new ContextMenuTest();
            swingView.createAndShowGUI();
        });

    }

    private void createAndShowGUI() {
        JFrame.setDefaultLookAndFeelDecorated(true);

        //Create and set up the window
        JFrame frame = new JFrame("Test Swing Frame");
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        JPanel mainPanel = new JPanel();
        mainPanel.setMinimumSize(new Dimension(600, 400));
        mainPanel.setPreferredSize(mainPanel.getMinimumSize());

        //add JavaFX panel to Swing main panel
        final JFXPanel fxMainPanel = new JFXPanel();
        mainPanel.add(fxMainPanel, "0,0");

        Platform.setImplicitExit(false);

        // create JavaFX scene
        Platform.runLater(() -> createScene(fxMainPanel));

        frame.getContentPane().add(mainPanel);

        //Display the window
        frame.pack();
        frame.setVisible(true);
    }

    private void createScene(JFXPanel fxMainPanel) {

        StackPane rootPane = new StackPane();
        rootPane.setPrefSize(100.0, 100.0);
        rootPane.setStyle("-fx-background-color: red");
        ContextMenu contextMenu = new ContextMenu();
        MenuItem menuItem = new MenuItem("Test Menu Item");
        contextMenu.getItems().add(menuItem);

        rootPane.setOnContextMenuRequested(event -> {
            contextMenu.show(rootPane, event.getScreenX(), event.getScreenY());
            System.out.println("Context menu requested");
            event.consume();
        });

        contextMenu.showingProperty().addListener((observable, oldValue, newValue) -> System.out.println("Context menu showing old = " + oldValue + ", new = " + newValue));

        Scene scene = new Scene(rootPane);
        fxMainPanel.setScene(scene);

    }
}