Bug 263878 [CSS] Implement active + selected tab colors for photo demo
examples/org.eclipse.e4.demo.e4photo/src/org/eclipse/e4/demo/e4photo/Library.java
};
	private final IWorkspace workspace;
	static int counter;
	public Library(Composite parent, final IWorkspace workspace, final IEclipseContext outputContext) {
		final Realm realm = SWTObservables.getRealm(parent.getDisplay());
		this.workspace = workspace;
		workspace.addResourceChangeListener(listener);
		TreeViewer viewer = new TreeViewer(parent, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);
		viewer.getTree().setData("org.eclipse.e4.ui.css.id", "library");
		viewer.getTree().setData("org.eclipse.e4.ui.css.CssClassName", "navigator");
		
		viewer.addSelectionChangedListener(new ISelectionChangedListener(){
			public void selectionChanged(SelectionChangedEvent event) {
				outputContext.set(IServiceConstants.SELECTION, event.getSelection());
			}
		});
		IObservableFactory setFactory = new IObservableFactory() {
			public IObservable createObservable(Object element) {
				if (element instanceof IContainer && ((IContainer)element).exists()) {
					IObservableSet observableSet = observableSets.get(element);
					if (observableSet == null) {
						observableSet = new WritableSet(realm);
						try {
							observableSet.addAll(Arrays
									.asList(((IContainer) element).members()));
						} catch (CoreException e) {
							
							e.printStackTrace();
						}
						observableSets.put((IContainer) element, observableSet);