Bug 315281 update copyrights for 3.6
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
/**
	 * Returns the rightmost visible descendent of the given item. Returns the
	 * item itself if it has no children.
	 *
	 * @param item
	 *            the item to compute the descendent of
	 * @return the rightmost visible descendent or the item itself if it has no
	 *         children
	 */
	private Item rightMostVisibleDescendent(Item item) {
		Item[] children = getItems(item);
		if (getExpanded(item) && children != null && children.length > 0) {
			return rightMostVisibleDescendent(children[children.length - 1]);
		}
		return item;
	}
	
	public Item scrollDown(int x, int y) {
		Item current = getItem(x, y);
		if (current != null) {
			Item next = getNextItem(current, true);
			showItem(next == null ? current : next);
			return next;
		}
		return null;
	}
	
	public Item scrollUp(int x, int y) {
		Item current = getItem(x, y);
		if (current != null) {