Bug 27491 Cannot add classpath variable to project
build id : 200212020010 The buttons OK and extend... are always disabled in the add variable dialog
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/dialogfields/ListDialogField.java
private boolean[] fButtonsEnabled;
	
	private int fRemoveButtonIndex;
	private int fUpButtonIndex;
	private int fDownButtonIndex;
	
	private Label fLastSeparator;
	
	private Table fTableControl;
	private Composite fButtonsControl;
	private ISelection fSelectionWhenEnabled;
	
	private IListAdapter fListAdapter;
	
	private Object fParentElement;
	
	private ColumnsDescription fTableColumns;
	
	/**
	 * Creates the <code>ListDialogField</code>.
	 * @param adapter A listener for button invocation, selection changes.
	 * @param buttonLabels The labels of all buttons: <code>null</code> is a valid array entry and
	 * marks a separator.
	 * @param lprovider The label provider to render the table entries
	 */	
	public ListDialogField(IListAdapter adapter, String[] buttonLabels, ILabelProvider lprovider) {
		super();
		fListAdapter= adapter;
		fLabelProvider= lprovider;