code: public List<JavaResource> getProjectEventTypes(Project project)
     {
        final List<JavaResource> eventTypes = new ArrayList<>();
        if (project != null)
        {
           project.getFacet(JavaSourceFacet.class).visitJavaSources(new JavaResourceVisitor()
           {
              @Override
              public void visit(VisitContext context, JavaResource resource)
              {
                 eventTypes.add(resource);
              }
           });
        }
        return eventTypes;
     }
docs: Returns all the possible event types from the given {@link Project}