/**
* Get all available elements.
*
* @return the available elements
*/
protected Collection<?> getAvailableElements() {
final Collection<FilterDescription> result = new HashSet<FilterDescription>();
if (diagram != null && diagram.getDescription() != null) {
final DiagramDescription desc = diagram.getDescription();
result.addAll(desc.getFilters());
}
result.removeAll(getAppliedElements());
return result;
}
