}
ContributionItemUpdater listener = new ContributionItemUpdater(item,
identifier);
if (visibleWhen != AlwaysEnabledExpression.INSTANCE) {
IEvaluationReference ref = evaluationService.addEvaluationListener(
visibleWhen, listener, PROP_VISIBLE, restriction);
evaluationsByItem.put(item, ref);
}
activityListenersByItem.put(item, listener);
}