class ChromeWebNavigation extends ChromeApi {
 static final JsObject _webNavigation = chrome['webNavigation'];

 ChromeWebNavigation._();

 bool get available => _webNavigation != null;

 /**
  * Retrieves information about the given frame. A frame refers to an
  * <iframe> or a <frame> of a web page and is identified by a tab
  * ID and a frame ID.
  * 
  * [details] Information about the frame to retrieve information about.
  * 
  * Returns:
  * Information about the requested frame, null if the specified frame ID
  * and/or tab ID are invalid.
  */
 Future<Map> getFrame(WebNavigationGetFrameParams details) {
   if (_webNavigation == null) _throwNotAvailable();

   var completer = new ChromeCompleter<Map>.oneArg(mapify);
   _webNavigation.callMethod('getFrame', [jsify(details), completer.callback]);
   return completer.future;
 }

 /**
  * Retrieves information about all frames of a given tab.
  * 
  * [details] Information about the tab to retrieve all frames from.
  * 
  * Returns:
  * A list of frames in the given tab, null if the specified tab ID is invalid.
  */
 Future<List<Map>> getAllFrames(WebNavigationGetAllFramesParams details) {
   if (_webNavigation == null) _throwNotAvailable();

   var completer = new ChromeCompleter<List<Map>>.oneArg((e) => listify(e, mapify));
   _webNavigation.callMethod('getAllFrames', [jsify(details), completer.callback]);
   return completer.future;
 }

 /**
  * Fired when a navigation is about to occur.
  */
 Stream<Map> get onBeforeNavigate => _onBeforeNavigate.stream;

 final ChromeStreamController<Map> _onBeforeNavigate =
     new ChromeStreamController<Map>.oneArg(_webNavigation, 'onBeforeNavigate', mapify);

 /**
  * Fired when a navigation is committed. The document (and the resources it
  * refers to, such as images and subframes) might still be downloading, but at
  * least part of the document has been received from the server and the
  * browser has decided to switch to the new document.
  */
 Stream<Map> get onCommitted => _onCommitted.stream;

 final ChromeStreamController<Map> _onCommitted =
     new ChromeStreamController<Map>.oneArg(_webNavigation, 'onCommitted', mapify);

 /**
  * Fired when the page's DOM is fully constructed, but the referenced
  * resources may not finish loading.
  */
 Stream<Map> get onDOMContentLoaded => _onDOMContentLoaded.stream;

 final ChromeStreamController<Map> _onDOMContentLoaded =
     new ChromeStreamController<Map>.oneArg(_webNavigation, 'onDOMContentLoaded', mapify);

 /**
  * Fired when a document, including the resources it refers to, is completely
  * loaded and initialized.
  */
 Stream<Map> get onCompleted => _onCompleted.stream;

 final ChromeStreamController<Map> _onCompleted =
     new ChromeStreamController<Map>.oneArg(_webNavigation, 'onCompleted', mapify);

 /**
  * Fired when an error occurs and the navigation is aborted. This can happen
  * if either a network error occurred, or the user aborted the navigation.
  */
 Stream<Map> get onErrorOccurred => _onErrorOccurred.stream;

 final ChromeStreamController<Map> _onErrorOccurred =
     new ChromeStreamController<Map>.oneArg(_webNavigation, 'onErrorOccurred', mapify);

 /**
  * Fired when a new window, or a new tab in an existing window, is created to
  * host a navigation.
  */
 Stream<Map> get onCreatedNavigationTarget => _onCreatedNavigationTarget.stream;

 final ChromeStreamController<Map> _onCreatedNavigationTarget =
     new ChromeStreamController<Map>.oneArg(_webNavigation, 'onCreatedNavigationTarget', mapify);

 /**
  * Fired when the reference fragment of a frame was updated. All future events
  * for that frame will use the updated URL.
  */
 Stream<Map> get onReferenceFragmentUpdated => _onReferenceFragmentUpdated.stream;

 final ChromeStreamController<Map> _onReferenceFragmentUpdated =
     new ChromeStreamController<Map>.oneArg(_webNavigation, 'onReferenceFragmentUpdated', mapify);

 /**
  * Fired when the contents of the tab is replaced by a different (usually
  * previously pre-rendered) tab.
  */
 Stream<Map> get onTabReplaced => _onTabReplaced.stream;

 final ChromeStreamController<Map> _onTabReplaced =
     new ChromeStreamController<Map>.oneArg(_webNavigation, 'onTabReplaced', mapify);

 /**
  * Fired when the frame's history was updated to a new URL. All future events
  * for that frame will use the updated URL.
  */
 Stream<Map> get onHistoryStateUpdated => _onHistoryStateUpdated.stream;

 final ChromeStreamController<Map> _onHistoryStateUpdated =
     new ChromeStreamController<Map>.oneArg(_webNavigation, 'onHistoryStateUpdated', mapify);

 void _throwNotAvailable() {
   throw new UnsupportedError("'chrome.webNavigation' is not available");
 }
}