BorderLayoutPanel

Code of this view Basepack::BorderLayoutPanel, besides easy nesting of other components, keeps track of its regions' sizes and collapsed/expanded states. Try to resize or collapse regions, then refresh the page. Note, that the state is stored in the database, not in the session.
Also note, that it's a very simple component, which simply puts together several GridPanel's with different configuration, without implementing any interaction between them (unlike in this tutorial).