title: Give thumbnail image with UIActivityViewController
body: <p>I'm trying to share an image with text through <code>UIActivityViewController</code>. If I do this: </p>
  
  <pre><code>        let activityVC = UIActivityViewController(activityItems: [text, image], applicationActivities: nil)
          self.presentViewController(activityVC, animated: true, completion: nil)
  </code></pre>
  
  <p>Everything works fine. The problem is that I only want to share the image with certain activity types. i.e. when a user shares to Facebook I don't want to have an image, for everything else I do though. My problem is this stupid method is never called: </p>
  
  <pre><code>optional func activityViewController(_ activityViewController: UIActivityViewController,
         thumbnailImageForActivityType activityType: String?,
                         suggestedSize size: CGSize) -&gt; UIImage?
  </code></pre>
  
  <p>Which should be becuase it's defined in <code>UIActivityItemSource</code> protocol. Is there any work around to this? </p>
  
  <hr>
  
  <p>So I believe to have made some headway here. Turns our if you pass multiple values of <code>self</code> when instantiating <code>UIActivityViewController</code> you can return multiple values in the <code>itemForActivityType</code> delegate method. So if I do this: </p>
  
  <pre><code>let activityVC = UIActivityViewController(activityItems: [self, self], applicationActivities: nil)
  </code></pre>
  
  <p>I can return different values like this: </p>
  
  <pre><code>func activityViewController(activityViewController: UIActivityViewController, itemForActivityType activityType: String) -&gt; AnyObject? {
      if activityType == UIActivityTypePostToFacebook {
          return ["hello", "world"]
      }
      else {
          return ["goodnight", "moon"]
      }
  }
  </code></pre>
  
  <p>However, it seems that you can only return two values of the same type. </p>
  
  <p>My new question is now, how would I return both an image and text?? The hunt continues...</p>