Bug 24521 [Viewers] TreeViewer.update() does not work correctly with filter
When I add an element which does not satisfy the filtering condition and then update it so that it does, call to update does not show the element. This is because[StructuredViewer.update]: public void update(Object element, String[] properties) { Assert.isNotNull(element); | Widget item = findItem(element); | if (item == null) | return; the code silently ignores that the element may become visible... btw. later in code of this method: if (needsRefilter) { refresh(); return; } This is quite inefficient, as it needs to query all visible items; however only one element may actually change (change visibility and/or sort order).
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
* @return the list of selected elements
	 */
	protected abstract List getSelectionFromWidget();
	/**
	 * Returns the sorted and filtered set of children of the given element. The
	 * resulting array must not be modified, as it may come directly from the
	 * model's internal state.
	 * 
	 * @param parent
	 *            the parent element
	 * @return a sorted and filtered array of child elements
	 */
	protected Object[] getSortedChildren(Object parent) {
		Object[] result = getFilteredChildren(parent);
		if (sorter != null) {
			
			result = (Object[]) result.clone();
			sorter.sort(this, result);
		}
		return result;
	}
	/**
	 * Returns this viewer's sorter, or <code>null</code> if it does not have
	 * one.  If this viewer has a comparator that was set via 
	 * <code>setComparator(ViewerComparator)</code> then this method will return 
	 * <code>null</code> if the comparator is not an instance of ViewerSorter.
     * <p>
     * It is recommended to use <code>getComparator()</code> instead.
     * </p>
	 *