Test Page for sap.ui.ux3.NavigationBar
A NavigationBar filling 100% of the page width (minus the default margin) and no initial selection:
Another NavigationBar in a container that only has 50% width and the second item selected initially (this one opens an alert box on selection):
Another NavigationBar (in a 500px container) with an enormous amount of items:
NavigationBar not owning the items, but only being associated with them:
NavigationBar where navigation to item 3 is disabled using preventDefault():