NW.js - check if confirm window has focus

Question

I want to minimize the app when it loses focus:

nw.Window.get().on('blur', function() {nw.Window.get().minimize();});

Except, I have a confirm() dialog on exit, and, every time I press "cancel", this code triggers (window minimizes). How can I add an additional check for the popup's focus? I can't find a mention in the docs to identify each window, and also no way to check if no NW.js windows are focused.