How are android 3.0 browser layouts done? [closed]

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its cur开发者_Python百科rent form. For help clarifying this question so that it can be reopened, visit the help center. Closed 11 years ago.

First some screens:

Default:

Nice effect:

Cool hiding:

Detecting hidden:

The question is how to do this cool hiding? As you see, the navigation bar disappears as the WebView (?) is scrolling up. I don't have a clue how they did do that... Any ideas?

And how do they detect that the scrollbar should be hidden? When it's hidden cool arrow appears on tab.