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>preserveSelection</code>, the call to
		 * <code>updateSelection</code> is delayed until the end of
		 * <code>preserveSelection</code>.
		 * </p>
		 * <p>
		 * Subclasses do not typically override this method, but implement
		 * <code>setSelectionToWidget</code> instead.
		 * </p>
		 */
		Control control = getControl();
		if (control == null || control.isDisposed()) {
			return;
		}
		if (!inChange) {
			setSelectionToWidget(selection, reveal);
			ISelection sel = getSelection();
			updateSelection(sel);
			firePostSelectionChanged(new SelectionChangedEvent(this, sel));
		} else {
			restoreSelection = false;
			setSelectionToWidget(selection, reveal);
		}
	}
	/**
	 * Parlays the given list of selected elements into selections on this
	 * viewer's control.
	 * <p>
	 * Subclasses should override to set their selection based on the given list
	 * of elements.
	 * </p>