1. Dart
2. dart:html
3. WindowClient
4. visibilityState property

##### WindowClient class

1. Properties
2. focused
3. visibilityState
4. frameType
5. hashCode
6. id
7. runtimeType
8. type
9. url
10. Methods
11. focus
12. navigate
13. noSuchMethod
14. postMessage
15. toString
16. Operators
17. operator ==

# visibilityState property

String visibilityState
final

## Implementation

    final String visibilityState