UILabelのテキストの一部をハイパーリンク化

This post is about how to make hyperlink of words in UILabel.

Purpose

Personal Note

Development Environment

• OS X El Captain 10.11.2
• Xcode Version 8.0

Language

Swift 3.0

Code

    @IBOutlet weak var yourLabel: UILabel!
    var targetRect: CGRect = CGRect()
    // Hyper Link
    func setHyperLink(hyperlinkText: String){
        let text = "Hello Qiita Hello Law Hello Guys"

        yourLabel.backgroundColor = UIColor.clear
        yourLabel.textAlignment = .left

        let nsText = text as NSString
        let linkRange = text.range(of: hyperlinkText)

        let style = NSMutableParagraphStyle()
        style.alignment = NSTextAlignment.left

        let attributedString = NSMutableAttributedString(string: text, attributes: [ NSParagraphStyleAttributeName: style ])

        let firstStart = text.distance(from: text.startIndex, to: linkRange!.lowerBound)
        let firstLength = hyperlinkText.characters.count
        let firstRange = NSMakeRange(firstStart, firstLength)
        let boldFontAttribute = [NSFontAttributeName: UIFont.boldSystemFont(ofSize: 13.0)]

        // all text colour
        attributedString.addAttribute(NSForegroundColorAttributeName, value: UIColor.black, range: NSMakeRange(0, nsText.length))
        // link colour
        attributedString.addAttribute(NSForegroundColorAttributeName, value: UIColor.black, range: firstRange)
        attributedString.addAttributes(boldFontAttribute, range: firstRange)
        yourLabel.attributedText = attributedString

        yourLabel.isUserInteractionEnabled = true
        targetRect = getRect(str: yourLabel.attributedText!, range: firstRange, width: yourLabel.frame.width)
        yourLabel.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(self.tapText(sender:))))
    }

    func getRect(str: NSAttributedString, range: NSRange, width: CGFloat) -> CGRect {
        let storage = NSTextStorage(attributedString: str)
        let container = NSTextContainer(size: CGSize(width: width, height: CGFloat.greatestFiniteMagnitude))
        let layoutManager = NSLayoutManager()
        layoutManager.addTextContainer(container)
        storage.addLayoutManager(layoutManager)
        container.lineFragmentPadding = 0
        let pointer = UnsafeMutablePointer<NSRange>.allocate(capacity: 1)
        layoutManager.characterRange(forGlyphRange: range, actualGlyphRange: pointer)
        return layoutManager.boundingRect(forGlyphRange: pointer.move(), in: container)
    }

    func tapText(sender: UITapGestureRecognizer) {
        if targetRect.contains(sender.location(in: sender.view)) {
            // add your action from here
        }
    }

However, this code is not compatible with Emoji... counting emoji characters is still problematic.