title: Update interface orientation manually in iOS
body: <p>My iOS application supports all orientations except PortraitUpsideDown.
  But in the application I have an view with preferences which I want it to only be shown in Portrait orientation. So whenever this view is shown, it is rotated if needed, to be in portrait mode. That means that user will rotate device in portrait mode also, to setup preferences, and then after closing this view interface should now have portrait orientation.
  The problem is, that after preferences view is hidden interface stays in landscape orientation, since I block autorotation after this view is shown. 
  So after the view is hidden I want to manually update the interface to current device orientation. How can I do it?</p>
  
  <hr>
  
  <pre><code>self.view.hidden=NO;
  [UIView beginAnimations:nil context:NULL];
  [UIView setAnimationDuration:0.3];
  [UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
  self.view.alpha=1.0;
  [UIView commitAnimations];
  </code></pre>
  
  <p>This code is called from the OptionsViewController after a LongPressGesture on its superview.</p>