Bug 177405 [Preferences] Layout issues with Text Boxes and Scrollbars
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
/**
	 * Flag for the presence of the error message.
	 */
	private boolean showingError = false;
	/**
	 * Preference store, initially <code>null</code> meaning none.
	 * 
	 * @see #setPreferenceStore
	 */
	private IPreferenceStore preferenceStore;
	private Composite titleArea;
	/**
	 * The tree viewer.
	 */
	private TreeViewer treeViewer;
	
    private ListenerList pageChangedListeners = new ListenerList();
    /**
     *  Composite with a FormLayout to contain the title area
     */
    Composite formTitleComposite;
	private ScrolledComposite scrolled;
	/**
	 * Creates a new preference dialog under the control of the given preference
	 * manager.
	 * 
	 * @param parentShell
	 *            the parent shell
	 * @param manager
	 *            the preference manager