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
fireDoubleClick(new DoubleClickEvent(viewer, viewer
						.getSelection()));
				fireOpen(new OpenEvent(viewer, viewer.getSelection()));
			}
		};
	}
	/**
	 * Returns whether there is an active cell editor.
	 * 
	 * @return <code>true</code> if there is an active cell editor, and
	 *         <code>false</code> otherwise
	 * @since 3.1
	 */
	public boolean isCellEditorActive() {
		return treeViewerImpl.isCellEditorActive();
	}
	/*
	 * (non-Javadoc) Method declared in AbstractTreeViewer.
	 */
	protected Item newItem(Widget parent, int flags, int ix) {
		TreeItem item;
		
		if (parent instanceof TreeItem) {
			item = (TreeItem)createNewRowPart(getRowPartFromItem(parent),flags, ix).getItem();
		} else {
			item = (TreeItem)createNewRowPart(null,flags, ix).getItem();
		}
		
		return item;
	}