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/ViewerRow.java
*/
public abstract class ViewerRow {
	/**
	 * Key used to reference ViewerRow in the widgets data-map
	 */
	public static final String ROWPART_KEY = Policy.JFACE + ".ROWPART"; 
		
	/**
	 * Create a new instance of the receiver.
	 * @param item
	 */
	ViewerRow(final Item item) {
		item.setData(ViewerRow.ROWPART_KEY, this);
		item.addDisposeListener(new DisposeListener() {
			/* (non-Javadoc)
			 * @see org.eclipse.swt.events.DisposeListener#widgetDisposed(org.eclipse.swt.events.DisposeEvent)
			 */
			public void widgetDisposed(DisposeEvent e) {
				item.setData(ROWPART_KEY, null);
			}
			
		});
	}
	
	/**
	 * Get the bounds of the entry at the columnIndex,
	 * @param columnIndex
	 * @return Rectangle
	 */
	public abstract Rectangle getBounds(int columnIndex);