How to resized scale UIImageView in textview like Scale Aspect Fit swift?

Question

Hey I create a textview and I can add images in this textview.This image's width equal to textview's width. But I want to give a maximum height for this ImageView and I want to show the image like content mode scale aspect fit but it shows stretched(compressed aspect fill) how can I solve this situation ? Code like below

  let image = UIImageView()
  image.contentMode = .scaleAspectFit
  let imageAttachment = NSTextAttachment()
  let newImageWidth = self.textView.bounds.width
  let newImageHeight = 200
  imageAttachment.bounds = CGRect(x: 0, y: 0, width: Int(newImageWidth), height: newImageHeight)
  imageAttachment.image = image.image

Answer 1

This is how you would calculate the new height for an aspectFit ratio:

    // don't use "image" ... that's confusing
    let imageView = UIImageView()

    // assuming you set the image here
    imageView.image = UIImage(named: "myImage")

    guard let imgSize = imageView.image?.size else {
        // this will happen if you haven't set the image of the imageView
        fatalError("Could not get size of image!")
    }

    let imageAttachment = NSTextAttachment()
    let newWidth = self.textView.bounds.width

    // get the scale of the difference in width
    let scale = newWidth / imgSize.width

    // multiply image height by scale to get aspectFit height
    let newHeight = imgSize.height * scale

    imageAttachment.bounds = CGRect(x: 0, y: 0, width: newWidth, height: newHeight)
    imageAttachment.image = imageView.image