NetBeans Plugin - NullPointer exception when embedding JavaFX in a Swing TopComponent, then maximizing

Question

I am writing a NetBeans plugin which requires some graphs. I am seeing a NullPointer exception when I embed a JavaFX chart into a TopComponent. When I maximize any other TopComponent I have created for my plugin, I see the following exception:

java.lang.NullPointerException
   at javafx.embed.swing.JFXPanel$HostContainer$1.run(Unknown Source)
   at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
   at java.awt.EventQueue.access$200(EventQueue.java:103)
   at java.awt.EventQueue$3.run(EventQueue.java:694)
   at java.awt.EventQueue$3.run(EventQueue.java:692)
   at java.security.AccessController.doPrivileged(Native Method)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
[catch] at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

The plugin still runs and there seems to be nothing else wrong other than this exception popping up. The TopComponent is registered with

@TopComponent.Registration(mode = "commonpalette", openAtStartup = true)

and the persistence type persistenceType = TopComponent.PERSISTENCE_NEVER

I am creating the chart with

Platform.setImplicitExit(false);
Platform.runLater(new Runnable() {
        @Override
        public void run() {
            //creating scene here <other code>
            myPanel.setScene(scene);
        }
   });

and then adding it to a GroupLayout straight onto the TopComponent

this.setLayout(layout);
//then adding myPanel to the layout

If it is also of note, I see this error a lot too

Dangerous reflection access to sun.misc.SharedSecrets by class com.sun.javafx.tk.quantum.QuantumToolkit$17 detected!
code location: jar:file:/C:/<my_plugin>/build/cluster/modules/ext/jfxrt.jar!/

but have been led to believe I can ignore this?

Has anyone else come across this before or can see what is going wrong? I have tried other layouts, detecting when the JavaFX panel has been removed and haven't found a solution yet. Any suggestions would be much appreciated :)

For reference, my JavaFX version is 2.2.45 with the NetBeans IDE up to date.

Thanks

Answer 1

Solved this in the end, it involved listening for when the topcomponent's jpanel became null, then removing the javafx panel, readding later when it was shown.