How to add images as text attachment in Swift using nsattributedstring

knorrhane picture knorrhane · Sep 25, 2015 · Viewed 12.3k times · Source

I'm trying to build a custom keyboard for iOS using images which I've put in as buttons. When I press a button, the image linked to the button is put into an attributed string which is loaded into an UiTextView inside the custom keyboard view. That is working.

The problem is that when I append a new image to the attributed string both the old and new images in the string are changing to the image I currently pressed on. I can't understand why the old images in the string are changing.

Any suggestions? I've tried using replaceCharactersInRange and insertAttributedString but can't get it to work. Here is the code (after viewDidLoad):

let textAttachment = NSTextAttachment()

let textView = UITextView(frame: CGRectMake(5, 5, 200, 40))
var attributedString = NSMutableAttributedString(string: "")

@IBAction func buttonPressed(button :UIButton) {

    let string = button.titleLabel?.text

    textAttachment.image = UIImage(named: "\(string!).png")!
    textAttachment.image = UIImage(CGImage: textAttachment.image!.CGImage!, scale: 6, orientation: .Up)
    let attrStringWithImage = NSAttributedString(attachment: textAttachment)
    attributedString.appendAttributedString(attrStringWithImage);


    textView.attributedText = attributedString;
  }

Thank you!

Answer

Shrawan picture Shrawan · Dec 30, 2016

We cannot simply append NSTextAttachment image .We have to store all the attached Image and concatenation to existing attributed String.

func buttonPressed(_ sender: Any) {

    let  button = sender as! UIButton
    let tag =  button.tag
    let attributedString:NSAttributedString!

    switch tag {
    case 2:
        attributedString = addAttributedText(text: (button.titleLabel?.text)!)
    case 3:
        attributedString = addAttributedText(text: (button.titleLabel?.text)!)
    case 4:
        attributedString = addAttributedText(text: (button.titleLabel?.text)!)
    default:
       attributedString = addAttributedText(text: "launch")
      }
        textView.attributedText = attributedString
    }

    func addAttributedText(text:String) -> NSAttributedString {
        textViewDidChange(textView)
        let axtractedImageAttribute = NSMutableAttributedString()
        for image in imageArray {
            let attachment:NSTextAttachment = NSTextAttachment()
            attachment.image = image
            attachment.setImageHeight(height: 20)
            let attachmentString:NSAttributedString = NSAttributedString(attachment: attachment)
            axtractedImageAttribute.append(attachmentString)
        }

        let attachment:NSTextAttachment = NSTextAttachment()
        attachment.image = UIImage(named: "\(text).png")
        attachment.setImageHeight(height: 20)
        let attachmentString:NSAttributedString = NSAttributedString(attachment: attachment)
        let attributedString:NSMutableAttributedString = NSMutableAttributedString(string:textView.text!)
        attributedString.append(axtractedImageAttribute)
        attributedString.append(attachmentString)
        return attributedString
    }

    //MARKS:-  Extract attachedImage
    func textViewDidChange(_ textView: UITextView)  {
        imageArray = [UIImage]()
        let range = NSRange(location: 0, length: textView.attributedText.length)
        if (textView.textStorage.containsAttachments(in: range)) {
            let attrString = textView.attributedText
            var location = 0
            while location < range.length {
                var r = NSRange()
                let attrDictionary = attrString?.attributes(at: location, effectiveRange: &r)
                if attrDictionary != nil {
                    let attachment = attrDictionary![NSAttachmentAttributeName] as? NSTextAttachment
                    if attachment != nil {
                        if attachment!.image != nil {
                            imageArray.append( attachment!.image!)
                        }
                    }
                    location += r.length
                }
            }
        }
    }

}

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