UITextView sizeThatFits gives an answer that's too short in Swift

Question

When you try and do a sizeThatFits on a UITextView, if you then set the height of said UITextView to the result, then it's too short! This answer:

UITextView Content Size too Short

Also seems to fall short as, if you examine the contentInset property of the text view, the contentInset is all set to zeroes.

Answer 1

The key it use textContainerInset rather than contentInset. This will give you the proper buffer on the top and bottom that you're looking for. So, you'll get something like:

textView.text = "Some multiline text";
let size: CGSize = textView.sizeThatFits(CGSizeMake(textView.frame.size.width, CGFloat.max));
let insets: UIEdgeInsets = textView.textContainerInset; 
textViewHeight.constant = size.height + insets.top + insets.bottom;

It's also important to note, that this method must be called after the UITextView has been rendered. In other words, I originally was resizing this in the viewDidLoad method of the controller, when in actuality it had to be in viewDidAppear. This is annoying since the view is already displayed, but I solved it by fading in the few for better aesthetics.