In angular, you usually don't add classes based on action, but rather based on the status of your app. For example, if you were select one of many items in a list, you could change it's selected attribute to "true".
For example:
$scope.items = [{id: 1, name: "test", selected: false}, {id: 2, name: "test 2", selected: true}, {id: 3, name: "test 3", selected: false}]
Then in your template, you will use ng-class to let angular handle changing classes:
<ul>
<li ng-repeat="item in items" ng-class="{ selected: item.selected }">{{item.name}}</li>
</ul>
In the case of your navbar, I would actually think about your app state. Is this navbar reflective of your current location in the app? If that's the case, you should start checking your $routeParams (or $stateParams if you use the excellent ui-router) and conditionally adding classes that way.
The point here is that angular-fying an app is more than porting jQuery actions; it's about building a smarter app.