private static ISchedulingRule calcRefreshRule(IResource[] resources) {
List<ISchedulingRule> rules = new ArrayList<ISchedulingRule>();
IResourceRuleFactory ruleFactory = ResourcesPlugin.getWorkspace()
.getRuleFactory();
for (IResource resource : resources) {
ISchedulingRule rule = ruleFactory.refreshRule(resource);
if (rule != null)
rules.add(rule);
}
if (rules.size() == 0)
return null;