Bug 154064 Need a way to access the TreeItem or TableItem on a refresh
It is not currently possible to know when an item is refreshed. This is required for ownerDraw support in viewers.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
initTreeViewerImpl();
	}
	/*
	 * (non-Javadoc) Method declared in AbstractTreeViewer.
	 */
	protected void addTreeListener(Control c, TreeListener listener) {
		((Tree) c).addTreeListener(listener);
	}
	/**
	 * Cancels a currently active cell editor. All changes already done in the
	 * cell editor are lost.
	 * 
	 * @since 3.1
	 */
	public void cancelEditing() {
		treeViewerImpl.cancelEditing();
	}
	/*
	 * (non-Javadoc) Method declared in AbstractTreeViewer.
	 */
	protected void doUpdateItem(final Item item, Object element) {
 		if (!(item instanceof TreeItem)) {
			return;
		}
		TreeItem treeItem = (TreeItem) item;
		if (treeItem.isDisposed()) {
			unmapElement(element, treeItem);
			return;
		}
		int columnCount = getTree().getColumnCount();