NSMutableAttributedString in UILabel with alternate baselineOffset - ios

Question

I have a case where I want to display some sort of Footnote-Text in a UILabel. The text is prefixed with a number as the corresponding index.
My first idea to solve this problem was to simply create a view-setup with an UILabel for the mark and the text each. This, however, involved a lot of fiddling with constraints and auto-layout, since I wanted to list all footnotes in a table.
Thus I came up with the idea of using NSMutableAttributedString and set the baseline/font-size for the mark and the text respectively. The resulting NSAttributedString could then be used in any Layout with an UILabel.
let footnote: NSMutableAttributedString = .init(string: mark, attributes: [
.foregroundColor: UIColor.myColor,
.font: UIFont.myFont(7),
.baselineOffset: 10,
])
disclaimer.append(.init(string: text, attributes: [
.foregroundColor: UIColor.myColor,
.font: UIFont.myFont(14),
]))
Or so I thought. Seems like the layout of either the UILabel or the UITableViewRow do not like text with alternating baselines, as the UILabel never resized to more 2 Lines. Everything beyond those 2 lines was cut off. Even setting the preferredMayLayoutWidth to help the layout out a bit did not work. It did scale the Label to the correct height, but the text was still missing as if it was cut-off.

Answer 1

So, to answer my own question (and to share this knowledge with whoever might stumble across the same problem), I was able to solve this problem with a very simple (admittedly not very elegant) fix.
All I had to do was to add some text before my mark with the modified baselineOffset. This way, the layout seems to be able to calculate the correct height while still rendering the mark and text properly. Since I did not want any additional text in my cells, I've used a Zero-Width Space character.
let footnote: NSMutableAttributedString = .init(string: "\u{200B}", attributes: [:])
footnote.append(.init(string: mark, attributes: [
.foregroundColor: UIColor.myColor,
.font: UIFont.myFont(7),
.baselineOffset: 10,
]))
footnote.append(.init(string: text, attributes: [
.foregroundColor: UIColor.myColor,
.font: UIFont.myFont(14),
]))