Bug 245437 [Preferences] (HEAD) Preference pages not scrollable (accessible) via keyboard
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
viewer.setLabelProvider(new PreferenceLabelProvider());
		viewer.setContentProvider(new PreferenceContentProvider());
		return viewer;
	}
	/**
	 * Add the listeners to the tree viewer.
	 * @param viewer
	 * 
	 * @since 3.1
	 */
	protected void addListeners(final TreeViewer viewer) {
		viewer.addPostSelectionChangedListener(new ISelectionChangedListener() {
			private void handleError() {
				try {
					
					
					
					viewer.removePostSelectionChangedListener(this);
					showPageFlippingAbortDialog();
					selectCurrentPageAgain();
					clearSelectedNode();
				} finally {
					viewer.addPostSelectionChangedListener(this);
				}
			}
			public void selectionChanged(SelectionChangedEvent event) {
				final Object selection = getSingleSelection(event.getSelection());
				if (selection instanceof IPreferenceNode) {
					BusyIndicator.showWhile(getShell().getDisplay(), new Runnable(){
						public void run() {