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
* <code>getInput</code>. Override if the root element is different from
	 * the viewer's input element.
	 * </p>
	 * 
	 * @return the root element, or <code>null</code> if none
	 */
	protected Object getRoot() {
		return getInput();
	}
	/**
	 * The <code>StructuredViewer</code> implementation of this method returns
	 * the result as an <code>IStructuredSelection</code>.
	 * <p>
	 * Subclasses do not typically override this method, but implement
	 * <code>getSelectionFromWidget(List)</code> instead.
	 * <p>
	 * @return ISelection
	 */
	public ISelection getSelection() {
		Control control = getControl();
		if (control == null || control.isDisposed()) {
			return StructuredSelection.EMPTY;
		}
		List list = getSelectionFromWidget();
		return new StructuredSelection(list, comparer);
	}
	/**
	 * Retrieves the selection, as a <code>List</code>, from the underlying
	 * widget.
	 *