I am trying to embed a remote image obtained from a URL into a text using TextKit2

I’m using NSTextAttachmentViewProvider but I can’t get it to work as expected.

There are two things I can’t understand.

• The height is not working

  • The code says height=25.0, but it is actually larger than that. Changing the value of height is not reflected.

• Horizontal images are not displayed properly.

  • After loading the image from the URL, CGRect is set again, but the width of the image remains the same

The behavior looks like this

enter image description here

The code looks like this

import SwiftUI
import SDWebImageSwiftUI

struct ContentView: View {

    @State private var text = "test"

    var body: some View {
        MFMTextView(text: $text)
            .frame(maxWidth: .infinity)
    }
}

let oyasu = URL(string:  "https://media.misskeyusercontent.jp/misskey/f75cd6a7-61f9-4e72-b47f-9ce0b5aa8602.png")!

struct MFMTextView: UIViewRepresentable {

    @Binding var text: String

    typealias UIViewType = UITextView

    func makeUIView(context: Context) -> UITextView {
        let textView = UITextView()
        textView.isEditable = false
        textView.delegate = context.coordinator
        return textView
    }

    func updateUIView(_ uiView: UITextView, context: Context) {
        let attributedText = NSMutableAttributedString()

        attributedText.append(NSAttributedString(string: text))
        attributedText.append(NSAttributedString(attachment: ImageAttachment(url: oyasu)))
        attributedText.append(NSAttributedString(string: text))
        uiView.attributedText = attributedText
    }

    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }

    class Coordinator: NSObject, UITextViewDelegate {
        var parent: MFMTextView

        init(_ parent: MFMTextView) {
            self.parent = parent
        }

        func textViewDidChange(_ textView: UITextView) {

        }
    }
}

final class ImageAttachment: NSTextAttachment {
    let imageUrl: URL

    init(url: URL) {
        self.imageUrl = url
        super.init(data: nil, ofType: nil)
        allowsTextAttachmentView = true
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func viewProvider(
        for parentView: UIView?,
        location: NSTextLocation,
        textContainer: NSTextContainer?
    ) -> NSTextAttachmentViewProvider? {
        let viewProvider = ImageAttachmentViewProvider(
            textAttachment: self,
            parentView: parentView,
            textLayoutManager: textContainer?.textLayoutManager,
            location: location,
            imageUrl: imageUrl
        )
        return viewProvider
    }
}

final class ImageAttachmentViewProvider: NSTextAttachmentViewProvider {
    let imageUrl: URL

    init(
        textAttachment: NSTextAttachment,
        parentView: UIView?,
        textLayoutManager: NSTextLayoutManager?,
        location: NSTextLocation,
        imageUrl: URL
    ) {
        self.imageUrl = imageUrl
        super.init(
            textAttachment: textAttachment,
            parentView: parentView,
            textLayoutManager: textLayoutManager,
            location: location
        )
        tracksTextAttachmentViewBounds = true
    }

    override func loadView() {
        let imageView = UIImageView()
        imageView.contentMode = .scaleAspectFill
        imageView.clipsToBounds = true
        SDWebImageDownloader.shared.downloadImage(with: imageUrl) { [weak self] (image, _, _, _) in
            DispatchQueue.main.async { [weak self] in
                imageView.image = image

                self?.updateViewSize(for: image)
            }
        }

        self.view = imageView
        self.view?.frame.size.height = 25.0
    }

    private func updateViewSize(for image: UIImage?) {
        guard let image = image else { return }
        let aspectRatio = image.size.width / image.size.height
        let height: CGFloat = 25
        let width = height * aspectRatio

        // Update the view frame with the new size
        view?.frame = CGRect(
            x: 0.0,
            y: 0.0,
            width: width,
            height: height
        )

        print(image.size.width)
        print(image.size.height)

        // Force layout update
        view?.setNeedsLayout()
        view?.layoutIfNeeded()
    }

    override func attachmentBounds(
        for attributes: [NSAttributedString.Key : Any],
        location: NSTextLocation,
        textContainer: NSTextContainer?,
        proposedLineFragment: CGRect,
        position: CGPoint
    ) -> CGRect {
        guard let imageView = view as? UIImageView, let image = imageView.image else {
            return .zero
        }
        let height = 25.0

        let aspectRatio = image.size.width / image.size.height
        let width = height * aspectRatio

        return CGRect(
            x: 0.0,
            y: 0.0,
            width: width,
            height: 100.0
        )
    }
}

Do you have any good ideas?

Or know of some good sample code?