AttributedTextView.swift

import SwiftUI

struct AttributedTextView: TextView, UIViewRepresentable {
    let content: NSAttributedString
    @Binding var height: CGFloat

    var font: UIFont? = nil
    var textAlignment: NSTextAlignment = .left
    var lineBreakMode: NSLineBreakMode = .byWordWrapping
    var textColor: UIColor = UIColor.label
    var backgroundColor: UIColor = UIColor.clear
    var disableInteraction = false
    var disableContextMenuInteraction = false

    public func makeUIView(context: Context) -> UITextView {
        let textView = UITextView()

        textView.isEditable = false
        textView.isUserInteractionEnabled = !self.disableInteraction
        textView.isScrollEnabled = false
        textView.automaticallyAdjustsScrollIndicatorInsets = false
        textView.textContainer.lineFragmentPadding = 0
        textView.textContainer.lineBreakMode = self.lineBreakMode
        textView.contentInset = .zero
        textView.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
        textView.font = self.font ?? UIFont.with(font: .body)
        textView.adjustsFontForContentSizeCategory = true
        textView.textAlignment = self.textAlignment
        textView.textColor = self.textColor
        textView.backgroundColor = self.backgroundColor
        textView.contentSize = .zero

        if self.disableContextMenuInteraction,
           let contextMenuInteraction = textView.interactions.filter({ $0 is UIContextMenuInteraction }).first as? UIContextMenuInteraction {
            textView.removeInteraction(contextMenuInteraction)
        }

        if let font = self.font {
            let content = NSMutableAttributedString(attributedString: self.content)
            content.replaceFont(with: font)
            textView.attributedText = content
            if self.lineBreakMode != .byWordWrapping {
                textView.textContainer.maximumNumberOfLines = Int(self.height / font.lineHeight)
            }
        } else {
            textView.attributedText = self.content
        }

        return textView
    }

    public func updateUIView(_ textView: UITextView, context: Context) {
        DispatchQueue.main.async {
            self.height = textView.sizeThatFits(textView.bounds.size).height
        }
    }
}

extension AttributedTextView {
    public func disableInteraction(_ disable: Bool?) -> AttributedTextView {
        var view = self
        view.disableInteraction = disable ?? false
        return view
    }

    public func disableContextMenuInteraction(_ disable: Bool?) -> AttributedTextView {
        var view = self
        view.disableContextMenuInteraction = disable ?? false
        return view
    }
}

private extension NSMutableAttributedString {
    func replaceFont(with font: UIFont) {
        beginEditing()
        self.enumerateAttribute(.font, in: NSRange(location: 0, length: self.length)) { (value, range, stop) in
            removeAttribute(.font, range: range)
            addAttribute(.font, value: font, range: range)
        }
        endEditing()
    }
}