title: keep keyboard from hiding UITextField at bottom of UITableView
body: <p>According to the answer at <a href="https://stackoverflow.com/questions/18047720/uitableview-make-footer-stay-at-bottom-of-screen">UITableView, make footer stay at bottom of screen?</a>, which I verify:</p>
  
  <blockquote>
    <p>In order to have a footer that stays put at the bottom of the screen,
    and doesn't scroll with the table, then you can't use a table view
    footer. You can't even use a UITableViewController, you'll need to
    implement your view controller as a UIViewController. Then you add
    your own table view as a subview. You'll also need to add your footer
    as a subview of the view controller's view, not the table view. Make
    sure you size the table view so its bottom is at the top of the footer
    view.</p>
  </blockquote>
  
  <p>but the problem is that my UITextField, inside my footer, is being hidden by the keyboard when user tries to type. So how do I keep the keyboard from hiding the UITextField? Throughout the app, I have been using TPKeyboardAvoiding. But in this case, where a UIScrollView/TPKeyboardAvoidingScrollView contains a UITableView and a UIView in vertical order, it does not work. I generally like TPKeyboardAvoiding because it’s so quick and easy. Any ideas how I might fix this issue?</p>