Bug 267117 [JFace] Provide possibility for subclasses to check if a column is visible in ViewerRow
Currently this is decided by checking with width but this makes Nebula-Grid fail.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ViewerRow.java
* one.
	 * <p>
	 * <b>Because of backwards API compatibility the default implementation
	 * returns the original index. Implementators of {@link ColumnViewer} should
	 * overwrite this method if their widget supports reordered columns</b>
	 * </p>
	 * 
	 * @param visualIndex
	 *            the current index (as shown in the UI)
	 * @return the original index
	 * @since 3.4
	 */
	protected int getCreationIndex(int visualIndex) {
		return visualIndex;
	}
	/**
	 * The location and bounds of the area where the text is drawn depends on
	 * various things (image displayed, control with SWT.CHECK)
	 * 
	 * @param index
	 *            the column index
	 * @return the bounds of the of the text area. May return <code>null</code>
	 *         if the underlying widget implementation doesn't provide this
	 *         information
	 * @since 3.4
	 */
	public Rectangle getTextBounds(int index) {
		return null;
	}
	/**