Bug 65276 [Preferences] Preference dialog should disable OK when okPressed
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
return viewer;
	}
	/**
	 * Find the <code>IPreferenceNode</code> that has data the same id as the
	 * supplied value.
	 * 
	 * @param nodeId
	 *            the id to search for.
	 * @return <code>IPreferenceNode</code> or <code>null</code> if not
	 *         found.
	 */
	protected IPreferenceNode findNodeMatching(String nodeId) {
		List nodes = preferenceManager
				.getElements(PreferenceManager.POST_ORDER);
		for (Iterator i = nodes.iterator(); i.hasNext();) {
			IPreferenceNode node = (IPreferenceNode) i.next();
			if (node.getId().equals(nodeId))
				return node;
		}
		return null;
	}
	/**
	 * Get the last known tree width.
	 * 
	 * @return the width.
	 */
	private int getLastTreeWidth() {
		return lastTreeWidth;
	}
	/**