java - Check if app is open during a GCM onMessage event?

Question

I am wondering how to check if my application is open and currently visible to the user when receiving an onMessage() from GCM. At first, I was just using my own boolean isVisible, but then I realized this isn't reliable, because if the app isn't open, the object I use to access that flag is null. While this in itself could be used to see if the app is open, it seems a little bit messy. Is there a way in Android from a system level to somehow check if the application is currently open, and if the user is viewing the app? Keep in mind an app could technically be running, but not be visible, because a user has recently pressed the "home" button sending it to the background.

@Override
protected void onMessage(Context arg0, Intent arg1) {
    String turn = intent.getExtras().getString("turn");
    if (turn.equals("yours"){
         if (/*app is open*/){ <------------------ what can go here?
             // dont generate a notification
             // display something in the game instead
         }
         else{
             // generate notification telling player its their turn
         }
    }
}

Answer 1

Waitting for answers