title: Checking for completed nav controller animation
body: <p>I now know that If you push a view controller onto a navigation controller with animation, you must wait until that animation has completed before pushing another view controller otherwise you get warnings and possibly unexpected results.</p>
  
  <p>How do you check to see if the nav controller animation has completed such to avoid this issue?</p>
  
  <p>Thanks</p>
  
  <pre><code>- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:    (NSIndexPath *)indexPath
  { 
      // ...
  
  
      //Make sure animation has completed before sending message below
  
  
  [[self navigationController] pushViewController:detailsViewController animated:NO];
  
  //...
  
  }
  </code></pre>