Bug 322356 EPS's isPartVisible(MPart) method does not consider placeholders
SSIA
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/PartServiceImpl.java
firePartActivated(activePart);
				}
			}
		}
	}
	@PostConstruct
	void postConstruct() {
		eventBroker.subscribe(UIEvents.buildTopic(UIEvents.ElementContainer.TOPIC,
				UIEvents.ElementContainer.SELECTEDELEMENT), selectedHandler);
		constructed = true;
		if (rootContainer == null) {
			
			
			
			application.getContext().runAndTrack(new RunAndTrack() {
				public boolean changed(IEclipseContext eventsContext) {
					IEclipseContext childContext = (IEclipseContext) eventsContext
							.getLocal(IContextConstants.ACTIVE_CHILD);
					if (childContext != null) {
						rootContainer = (MElementContainer<MUIElement>) childContext
								.get(MWindow.class.getName());
					}
					return true;
				}
			});
		}
	}
	@PreDestroy
	void preDestroy() {
		constructed = false;