vertically align text in a CATextLayer?

Question

I am working on a CATextLayer that I want to use in both Mac and iOS. Can I control the vertical alignment of the text within the layer?

In this particular case, I

Answer 1

Updating this thread (for single and multi line CATextLayer), combining some answers above.

class VerticalAlignedTextLayer : CATextLayer {

    func calculateMaxLines() -> Int {
        let maxSize = CGSize(width: frame.size.width, height: CGFloat(Float.infinity))
        let font = UIFont(descriptor: self.font!.fontDescriptor, size: self.fontSize)
        let charSize = font.lineHeight
        let text = (self.string ?? "") as! NSString
        let textSize = text.boundingRect(with: maxSize, options: .usesLineFragmentOrigin, attributes: [NSAttributedString.Key.font: font], context: nil)
        let linesRoundedUp = Int(ceil(textSize.height/charSize))
        return linesRoundedUp
    }
    
    override func draw(in context: CGContext) {
        let height = self.bounds.size.height
        let fontSize = self.fontSize
        let lines = CGFloat(calculateMaxLines())
        let yDiff = (height - lines * fontSize) / 2 - lines * fontSize / 10

        context.saveGState()
        context.translateBy(x: 0, y: yDiff) // Use -yDiff when in non-flipped coordinates (like macOS's default)
        super.draw(in: context)
        context.restoreGState()
    }
}