title: UICollectionView with ContentInset is not Scrolling all the Way Down
body: <p>I am setting the content inset of a UICollectionView:</p>
  
  <pre><code>[_collectionView setContentInset:UIEdgeInsetsMake(0.f, 0.f, 100.f, 0.f)];
  </code></pre>
  
  <p>Then I am scrolling programmatically all the way to the bottom of the UICollectionView with this method:</p>
  
  <pre><code>- (void)scrollToLastMessageAnimated:(BOOL)animated;
  {
      if (_messages.count == 0) { return; }
  
      NSUInteger indexOfLastSection = _messagesBySections.count - 1;
      NSInteger indexOfMessageInLastSection = [_messagesBySections[indexOfLastSection] count] - 1;
      NSIndexPath *path = [NSIndexPath indexPathForItem:indexOfMessageInLastSection
                                              inSection:indexOfLastSection];
  
      [_collectionView scrollToItemAtIndexPath:path
                             atScrollPosition:UICollectionViewScrollPositionCenteredVertically
                                     animated:animated];
  }
  </code></pre>
  
  <p>It is scrolling down, but it is ignoring the contentInset, meaning that the last cells are below the specified content inset:</p>
  
  <p><img src="https://i.stack.imgur.com/FUyYG.jpg" alt="enter image description here">
  The left image, shows how it appear now after the view did appear. In the right image, I manually scrolled further down to the last message.</p>
  
  <p>I am using AutoLayout, any ideas why this happens?</p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>Here is a screenshot of the IB setup:
  <img src="https://i.stack.imgur.com/nSWU2.png" alt="enter image description here"></p>