UITextView resizable by content with external height constraint

UITextViewResizable.swift

extension UITextView {
    open override func invalidateIntrinsicContentSize() {
        // UITextView intrinsicContentSize only exists if scrolling is disabled
        self.isScrollEnabled = false
        super.invalidateIntrinsicContentSize()
    }
    
    open override func layoutSubviews() {
        super.layoutSubviews()
        let contentSize = self.sizeThatFits(self.bounds.size)
        if contentSize.height > self.frame.height {
            self.isScrollEnabled = true
            return
        }
        self.isScrollEnabled = false
    }
}