A bug for Accessibility

on iOS, when VoiceOver is running, double click the UITextView can quickly switch the cursor between the beginning and end of the text.

Problem

the problem is, when the text contains some NSTextAttachment, this ability has failed.

Here is some code to reproduce this problem.

import UIKit

class ViewController: UIViewController {
    private var textView: UITextView?

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        view.backgroundColor = UIColor.white

        textView = UITextView(frame: CGRect(x: 60, y: 220, width: 240, height: 180))
        textView?.layer.borderColor = UIColor.black.cgColor
        textView?.layer.borderWidth = 1
        textView?.font = .systemFont(ofSize: 18)
        view.addSubview(textView!)

        let button = UIButton(type: .system)
        button.frame = CGRect(x: 120, y: 120, width: 60, height: 60)
        button.setTitle("click", for: .normal)
        button.addTarget(self, action: #selector(self.click), for: .touchUpInside)
        view.addSubview(button)
    }
    
    @objc func click() {
        let emojiImage = UIImage(systemName: "iphone.circle")
        let lineHeight = UIFont.systemFont(ofSize: textView!.font?.pointSize ?? 0.0).lineHeight
        let insertedAttr = generateAttributedString(image: emojiImage, bounds: CGRect(x: 0, y: -4, width: lineHeight, height: lineHeight))

        let attr = NSMutableAttributedString(attributedString: textView!.attributedText)
        attr.replaceCharacters(in: textView!.selectedRange, with: insertedAttr)
        textView!.attributedText = attr
    }
    
    public func generateAttributedString(image: UIImage?, bounds: CGRect) -> NSMutableAttributedString {
        let attachment = NSTextAttachment(data: nil, ofType: nil)
        attachment.bounds = bounds
        attachment.image = image

        let attrString = NSMutableAttributedString(attributedString: NSAttributedString(attachment: attachment))
        attrString.addAttribute(.font, value: textView!.font!, range: NSRange(location: 0, length: attrString.length))
        return attrString
    }
}