RulerColumnPreferenceAdapter adapter= null;
if (fPreferenceStore != null)
adapter= new RulerColumnPreferenceAdapter(getPreferenceStore(), PREFERENCE_RULER_CONTRIBUTIONS);
RulerColumnRegistry registry= RulerColumnRegistry.getDefault();
List descriptors= registry.getColumnDescriptors();
for (Iterator it= descriptors.iterator(); it.hasNext();) {
final RulerColumnDescriptor descriptor= (RulerColumnDescriptor) it.next();
support.setColumnVisible(descriptor, adapter == null || adapter.isEnabled(descriptor));
}
}