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 corresponding widgets
	 * 
	 * @since 3.2
	 */
	protected final Widget[] findItems(Object element) {
		Widget result = doFindInputItem(element);
		if (result != null) {
			return new Widget[] { result };
		}
		
		if (usingElementMap()) {
			Object widgetOrWidgets = elementMap.get(element);
			if (widgetOrWidgets==null) {
				return NO_WIDGETS;
			} else if (widgetOrWidgets instanceof Widget) {
				return new Widget[] {(Widget) widgetOrWidgets};
			} else {
				return (Widget[])widgetOrWidgets;
			}
		}
		result = doFindItem(element);
		return result == null ? NO_WIDGETS : new Widget[] { result };
	}
	/**
	 * Notifies any double-click listeners that a double-click has been
	 * received. Only listeners registered at the time this method is called are
	 * notified.
	 * 
	 * @param event
	 *            a double-click event