Access currently active displayed UIViewController
===

I want to present a ModalView, everytime my application receives a Pushnotification.
On arrival of the Notification, my app displays any of the `UIViewController`s within the app.

I need this `UIViewController` to call

    [presentingViewController presentModalViewController:vc animated:YES];
    // presentingViewController is what I need :)


**Is there a way to find out which UIViewController is currently active?**

I would know how to do this with e.g. `UITabbarController` or `UINavigationController`, but I can't rely on the presence of either of these.

I also tried getting the rootViewController via 

    [[[UIApplication sharedApplication] keyWindow] rootViewController]

and presenting the ModalView from there, but - of course - it wouldn't show for any other pushed/displayed views.