UITabBarController Like Apple's Remote App

Does anyone have an idea how Apple implemented the UITabBarController in the iOS Remote App (for controlling iTunes)?

Specifically, how the Remote will show a blacked out Tab Bar until the user selects an iTunes library (in a modal view), after which the tabs show "Songs," "Artists," etc.

Where would they have placed the logic to ch开发者_如何转开发eck that an iTunes library is selected and how do they blackout the tabs until it is?

Thanks

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You basically can set the UITabBarItem's enabled property to false.

Like:

[tabBarItem setEnabled: NO]; // to disable