Bug 155273 [Markers] Visibility of problems view columns should be configurable
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/CachedMarkerBuilder.java
/**
	 * Return the elements in the adapter.
	 * 
	 * @return MarkerSupportItem[]
	 */
	MarkerSupportItem[] getElements() {
		if (refreshingMarkers()) {
			return MarkerSupportInternalUtilities.EMPTY_MARKER_ITEM_ARRAY;
		}
		if (isShowingHierarchy() && categories != null) {
			return categories;
		}
		return currentMap.toArray();
	}
	/**
	 * Return the currently enabled filters.
	 * 
	 * @return Collection of MarkerFieldFilterGroup
	 */
	Collection getEnabledFilters() {
		if (enabledFilters == null) {
			enabledFilters = new HashSet();
			Iterator filtersIterator = getAllFilters().iterator();
			while (filtersIterator.hasNext()) {
				MarkerFieldFilterGroup next = (MarkerFieldFilterGroup) filtersIterator
						.next();
				if (next.isEnabled())
					enabledFilters.add(next);
			}
		}