Eclipse Community Forums: Eclipse 4 » NPE when using Dynamic Menu Contribution

Help

Home

Home » Eclipse Projects » Eclipse 4 » NPE when using Dynamic Menu Contribution

Show: Today's Messages :: Show Polls :: Message Navigator

NPE when using Dynamic Menu Contribution [message #1779180]

Wed, 03 January 2018 16:16

Marcus Tangermann

Messages: 4
Registered: June 2017

Junior Member

Hello,

I've implemented a dynamic menu contribution for a tree table according to http://blog.vogella.com/2013/03/21/dynamic-menu-contributions-in-eclipse-e4/ using the Oxygen.2 release (4.7.2).
Everything works well until the application is closed. During closing, NPEs occure:

java.lang.NullPointerException
	at org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:239)
	at org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(ContextInjectionFactory.java:132)
	at org.eclipse.e4.ui.workbench.renderers.swt.MenuManagerHideProcessor.lambda$0(MenuManagerHideProcessor.java:102)
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:37)
	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:182)
	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4213)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3820)
	at org.eclipse.swt.widgets.Display.release(Display.java:3874)
	at org.eclipse.swt.graphics.Device.dispose(Device.java:298)
	at org.eclipse.e4.ui.internal.workbench.swt.E4Application.start(E4Application.java:174)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:388)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:243)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:653)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:590)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1499)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1472)

It seems that for every time the dynamic menu is shown, one NPE occurs. So for example, showing the menu 4 times lead to 4 NPEs when the application is closed.

The NPE is caused in the processDynamicElements function where it tries to retrieve the object of the dynamic menu contribution. This object is null which leads to my assumption that it was already disposed. This null object is then forwarded to the invoke function where it causes the NPE.

Any idea what could cause this situation ?

Report message to a moderator

Re: NPE when using Dynamic Menu Contribution [message #1779220 is a reply to message #1779180]

Thu, 04 January 2018 07:47

Marcus Tangermann

Messages: 4
Registered: June 2017

Junior Member

Hi,

for now I've temporarly solved the problem by implementing an own MenuManagerHidedProcessor as described in https://www.eclipse.org/forums/index.php/t/1068074/
Nevertheless, I'm not sure what the root cause of the problem is and whether it is a bug in Eclipse or my fault.

Report message to a moderator

Re: NPE when using Dynamic Menu Contribution [message #1784942 is a reply to message #1779180]

Fri, 06 April 2018 07:59

Jürgen Weinberger

Messages: 42
Registered: August 2012

Member

Hi!
I have the same issue here. The same NPE as above appears, when i close my rcp application while a contextmenu with a dynamic Menu Contribution inside was shown. Even if the @AboutToShow is an empty method.
We are using eclipse 4.7.2 R2 as our targetplatform and the application runs in the compatibility mode.

If i remove the dynamic contribution from the fragment or close the application without having this contextmenu open, everything is fine.

I think this is a bug but i am not sure.
Best regards

Report message to a moderator