Vaadin Spring Integration

I am following this for spring-vaadin integration. But i am quite unable to understand in detail.

Is there a document or blog which explains in detail how vaadin ViewDisplay works. I need to understand, in this tutorial how the MyUI class method sets the DefaultView class for Panel in MyUI class at the start ?

May be I am missing something here. Please point me in right direction.

The Default View is the view annotated with @SpringView(name=“”)