Bug 153993 [Viewers] Common Baseclass for Tree/TableEditorImpl
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
index = getTree().indexOf(item);
						}
						virtualLazyUpdateWidget(parentItem == null ? (Widget)getTree() : parentItem, index);
					}
				}
			});
		}
	}
	/**
	 * Initializes the tree viewer implementation.
	 */
	private void initTreeViewerImpl() {
		treeViewerImpl = new TreeEditorImpl(this) {
			Rectangle getBounds(Item item, int columnNumber) {
				return ((TreeItem) item).getBounds(columnNumber);
			}
			int getColumnCount() {
				return getTree().getColumnCount();
			}
			Item[] getSelection() {
				return getTree().getSelection();
			}
			void setEditor(Control w, Item item, int columnNumber) {
				treeEditor.setEditor(w, (TreeItem) item, columnNumber);
			}
			void setSelection(IStructuredSelection selection, boolean b) {
				TreeViewer.this.setSelection(selection, b);
			}
			void showSelection() {
				getTree().showSelection();