HOWTO provide GUI feedback when a Job is completed

The Job framework is almost "The Framework" to use when executing any lengthy procedures inside Eclipse environment.
I've yet to encounter a scenario where IRunnableContext.run
(my original solace) can't be replaced by a Job well done (ya, corny).

So, back to the main question: How do you
respond "Job done!" to the user after your Job has finished execution? Simple, create an implementation of

IJobChangeListener. And, at the public void done(IJobChangeEvent event) do:

  // note: you'll have to call addJobChangeListener() before

  // schedule() for this to take effect..

  if (event.getResult().isOK()) {

    Display.getDefault().asyncExec(new Runnable() {

      public void run() {

        IAction action = new Action("Job Done") {

          public void run() {

            MessageDialog.openInformation(getShell(), 

              "Title", 

              "Job done!");

          }

        };

        action.run();

      }

    });

  }

Note that the bold section is the real meat of what you'd really wanted to do. But without doing all these Display...IAction..run thing, you'll definitely get the nasty org.eclipse.swt.SWTException: Invalid thread access

Read more here.