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
* @see StructuredViewer#setFilters(ViewerFilter[])
	 */
	public ViewerFilter[] getFilters() {
		if (filters == null) {
			return new ViewerFilter[0];
		}
		ViewerFilter[] result = new ViewerFilter[filters.size()];
		filters.toArray(result);
		return result;
	}
	/**
	 * Returns the item at the given display-relative coordinates, or
	 * <code>null</code> if there is no item at that location or 
	 * the underlying SWT-Control is not made up of {@link Item} 
	 * (e.g {@link ListViewer}) 
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * </p>
	 * 
	 * @param x
	 *            horizontal coordinate
	 * @param y
	 *            vertical coordinate
	 * @return the item, or <code>null</code> if there is no item at the given
	 *         coordinates
	 * @deprecated This method is deprecated in 3.3 in favor of {@link ColumnViewer#getItemAt(org.eclipse.swt.graphics.Point)}. 
	 * Viewers who are not subclasses of {@link ColumnViewer} should consider using a
	 * widget relative implementation like {@link ColumnViewer#getItemAt(org.eclipse.swt.graphics.Point)}.
	 *  
	 */