title: UITextField not receiving touch event
body: <p>I have a UITextField in a complex view hierarchy. The text field is in a UIView with label and textfield, say, labelfield.</p>
  
  <p>I can type text there. </p>
  
  <p>There is info button on top right corner. When tap on Info, a modal view controller is loaded. When coming back from the modal view controller, the UITextField becomes unresponsive. I cannt type anything there. The labelfiedl is drawn and shown in the screen. </p>
  
  <p>Interesting thing is that, if I press the ok button, and alert is shown and then the textfield  becomes active. Also, on top of the view, there is some text with user interaction enable, if I tap and try to select the text and after that the textfield becomes active. Seems I have to do some other activity/touch on the super view, then the text field becomes active. </p>
  
  <p>Why not on the first case it receive any touch event? I tried with textField.enabled, becomesFirstResponder, setNeedsDisplay in the viewDidApper method, nothing works.</p>
  
  <p><img src="https://i.stack.imgur.com/LnyHa.png" alt="enter image description here"></p>