Bug 167323 [Viewers]Open AbstractTreeViewer for external widget implementors
As reported by Ross Camara AbstractTreeViewer would work for nebula if we would open the API a bit. Boris and I decided that we will do this in 2 steps: 1. open the API 2. moving the Virtual-Support bits from TreeViewer to AbstractTreeViewer when the nebula grid provides virtual support.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
item.clear(0, true);
						}
					}
				}
			}
		});
	}
	/**
	 * Update the widget at index.
	 * @param widget
	 * @param index
	 */
	private void virtualLazyUpdateWidget(Widget widget, int index) {
		if (contentProviderIsTreeBased) {
			TreePath treePath;
			if (widget instanceof Item) {
				if (widget.getData() == null) {
					
					
					return;
				}
				treePath = getTreePathFromItem((Item) widget);
			} else {
				treePath = TreePath.EMPTY;
			}
			((ILazyTreePathContentProvider) getContentProvider())
					.updateElement(treePath, index);
		} else {
			((ILazyTreeContentProvider) getContentProvider()).updateElement(
					widget.getData(), index);