Bug 163317 [Viewers] Take over SWT programming pattern to JFace Viewers
To open ColumnViewer for reusablility we should not make it final making the constructor protected forces people to subclass it and not directly creating instances from it.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ColumnViewer.java
}
	/**
	 * Returns the viewer row at the given widget-relative coordinates.
	 * 
	 * @param point
	 *            the widget-relative coordinates of the viewer row
	 * @return ViewerRow the row or <code>null</code> if no row is found at
	 *         the given coordinates
	 */
	protected ViewerRow getViewerRow(Point point) {
		Item item = getItemAt(point);
		if (item != null) {
			return getViewerRowFromItem(item);
		}
		return null;
	}
	/**
	 * Returns the viewer row associated with the given row widget.
	 * 
	 * @param item the row widget
	 * @return ViewerRow the associated viewer row
	 */
	protected ViewerRow getViewerRowFromItem(Widget item) {
		return (ViewerRow) item.getData(ViewerRow.ROWPART_KEY);
	}
	/**
	 * Returns the column widget at the given column index.
	 * 
	 * @param columnIndex the column index
	 * @return Widget the column widget