public void fireAttributesVisibilityChangedEvent(OutlinerDocument doc) {
		attributesVisibilityChangedEvent.setOutlinerDocument(doc);
		for (int i = 0, limit = outlinerDocumentListeners.size(); i < limit; i++) {
			((OutlinerDocumentListener) outlinerDocumentListeners.get(i)).attributesVisibilityChanged(attributesVisibilityChangedEvent);
		}
		
		// Cleanup
		attributesVisibilityChangedEvent.setDocument(null);
	}