title: iOS - Present/Show ViewController while content underneath remains interactive
body: <p>I'd like to present/show a <code>ViewController</code> (let's call it <em>ViewController2</em>) that is somehow hidden (or have a 0 size) and, after some time, it'll be resized to a specific size (or fullscreen) meanwhile keeping the content of the <code>ViewController</code> (let's call it <em>ViewController1</em>) presenting/showing it interactive. </p>
  
  <p><a href="https://i.stack.imgur.com/iYSH4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iYSH4.png" alt="ViewControllers flow"></a></p>
  
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  <p>Just to give some more context on <em>why</em> I want to do that.</p>
  
  <p>I'm trying to load a <code>WKWebView</code> in the background and, ideally, would like to present the <code>ViewController</code> <strong>only</strong> when the webview is fully loaded. Unfortunately, <a href="https://stackoverflow.com/questions/31169884/wkwebkit-javascript-execution-when-not-attached-to-a-view-hierarchy">iOS seems to "pause" javascript evaluation and its timers</a> after a very short time <a href="https://stackoverflow.com/questions/53482566/wkwebview-doesnt-run-javascript-when-on-background">when the webview is not presented to the user</a>. </p>
  
  <p>I can confirm code like <code>setTimeout</code> stop working when the webview is attached to a ViewController which is not presented to the user and resumes working when that controller is presented/shown. </p>
  
  <p>My idea here is, presenting the controller right away but somehow hidden (while keeping the app interactive) and when getting the right signal from the webview, I'd show/resize it to the user. </p>