viewer = new TreeViewer(parent, SWT.SINGLE | (style & ~SWT.MULTI));
viewer.getTree().setLayoutData(new GridData(GridData.FILL_BOTH));
viewer
.setContentProvider(new AopReferenceModelNavigatorContentProvider());
viewer.setLabelProvider(new AopReferenceModelNavigatorLabelProvider());
viewer.setAutoExpandLevel(AbstractTreeViewer.ALL_LEVELS);
viewer.setSorter(new AopReferenceModelNavigatorSorter());
// adding these filters which restrict the contents of
// the view according to what has been typed in the