title: Today Extension view flashes when redrawing
body: <p>According to Apple documentation, "To help your widget look up to date, the system occasionally captures snapshots of your widget’s view. When the widget becomes visible again, the most recent snapshot is displayed until the system replaces it with a live version of the view."</p>
  
  <p>What I am seeing, however, is that the snapshot is removed from screen before the live view is prepared. This results in a flash effect where the old snapshot is taken off screen, the view is blank for a split second, then the new view appears.</p>
  
  <p>Is the developer responsible for making the transition between the snapshot and the live view seamless? If so, what is the strategy behind doing that? I don't see any way to directly control that transition.</p>
  
  <p>I was able to mitigate the effect greatly by moving data loading to 
  widgetPerformUpdateWithCompletionHandler: and keeping drawing in viewWillAppear:, but I do still see a flash once every 15 (or so) opens of the Notification Center.</p>