.ByTruncatingHead works the way truncatingmiddle should have when numberoflines is 0 for UILabel

Question

Code to reproduce this:

import UIKit
import PlaygroundSupport

class MyViewController : UIViewController {
    override func loadView() {
        let view = UIView()
        view.backgroundColor = .white

        let label = UILabel()
        label.frame = CGRect(x: 150, y: 200, width: 200, height: 70)
        label.lineBreakMode = .byTruncatingHead
        label.text = "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.Why do we use it?            It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here, content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their default model text, and a search for 'lorem ipsum' will uncover many web sites still in their infancy. Various versions have evolved over the years, sometimes by accident, sometimes on purpose (injected humour and the like).            Contrary to popular belief, Lorem Ipsum is not simply random text. It has roots in a piece of classical Latin literature from 45 BC, making it over 2000 years old. Richard McClintock, a Latin professor at Hampden-Sydney College in Virginia, looked up one of the more obscure Latin words, consectetur, from a Lorem Ipsum passage, and going through the cites of the word in classical literature, discovered the undoubtable source. Lorem Ipsum comes from sections 1.10.32 and 1.10.33 of ed since the 1500s is reproduced below for those interested. Sections 1.10.32 and 1.10.33 from de Finibus Bonorum et Malorum"
        label.numberOfLines = 0
        label.backgroundColor = .yellow
        label.textColor = .black
        
        view.addSubview(label)
        self.view = view
    }
}
// Present the view controller in the Live View window
PlaygroundPage.current.liveView = MyViewController()

The question is how would I get the multiline text head clipped as opposed to the linebreakmode apply to the last line only? Is there a way around this uikit deficiency?

Answer 1

The rule is that with a truncating policy, a UILabel breaks the text at word-end, and then, if the text is too long for the label, the last line displays an ellipsis at the start, middle, or end of the line respectively, and text is omitted at the point of the ellipsis.

So in fact your code does not behave the same way as byTruncatingMiddle, which puts the ellipses in the middle of the last line. Your code puts the ellipses at the start of the last line.