TextView subclass that animates resize as text is entered

ResizingTextView.swift

import UIKit

/// TextView subclass that animates resize as text is entered
/// Should be used with constraints that pin width so that contentView 
/// expands in height to accommodate the current text
class ResizingTextView: UITextView {
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        isScrollEnabled = false
        NotificationCenter.default.addObserver(self, selector: #selector(textChanged), name: NSNotification.Name.UITextViewTextDidChange, object: nil)
    }
    
    func textChanged() {
        UIView.animate(withDuration: 0.2, animations: {
            self.invalidateIntrinsicContentSize()
            self.superview?.setNeedsLayout()
            self.superview?.layoutIfNeeded()
        })
    }
}