LCLabel

LCLabel is a TextKit 2 based UILabel that mimics a the behaviour of UITextView

Installation

Swift Package Manager

File -> Swift Packages -> Add Package Dependency

Enter package URL: https://github.com/mustiikhalil/LCLabel

dependencies: [
  .package(
    name: "LCLabel",
    url: "https://github.com/mustiikhalil/LCLabel",
    from: "X.Y.Z"),
]

How to use:

let text = NSMutableAttributedString(
  string: "welcome to this new adventure!!!",
  attributes: [:])
let range = (text.string as NSString).range(of: "welcome")
text.addAttribute(
  .lclabelLink, // Note we use type `lclabelLink`
  value: URL(string: "tel://909001")!,
  range: range)
let label = LCLabel(
  frame: CGRect(
    origin: .zero, 
    size: .init(
      width: 300, 
      height: 30)))
label.isUserInteractionEnabled = true
label.delegate = self
label.attributedText = text
view.addSubview(label)

or incase AutoLayout is being used

let label = LCLabel(frame: .zero)
label.isUserInteractionEnabled = true
label.delegate = self
label.attributedText = text
view.addSubview(label)
label.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
  label.topAnchor.constraint(equalTo: view.topAnchor),
  label.leadingAnchor.constraint(equalTo: view.leadingAnchor),
  label.trailingAnchor.constraint(equalTo: view.trailingAnchor),
  label.bottomAnchor.constraint(equalTo: view.bottomAnchor)])

Notes:

While building it with TextKit was interesting, the following nits where found:

• Setting the styles for links are usually broken. There are two solutions for this: 1- Use type .lclabelLink instead of .link when creating your NSAttributedString

  2- Setting linkStyleValidation to be .ensure which will force the NSTextStorage to either replace all the instances of .link with .lclabelLink or takes values of linkAttributes and sets them to the Storage.

• linkAttributes would only be set if .ensure was set.

Getting started

git clone https://github.com/mustiikhalil/LCLabel
cd LCLabel
open DemoApp/DemoApp.xcodeproj
// or
open package.swift

• LCLabel has three schemas to build
  1. LCLabel // Lib
  2. DemoApp // Demo app & test cases
  3. UI Full Tests // UITests that includes hitches tests
• DemoApp explains how to use LCLabel
• DemoApp can be ran in three modes, -scrollview, -autolayout and default. You will need to pass the arguments as Arguments Passed On Launch
• UI Full Tests shows that LCLabel doesnt have any hitches The following was compared on an iPhone xs with a baseline of UILabel

Performance

Memory

Using UILabel as a baseline, we were able to achieve a similar performance to UILabel.

A simple text in a LCLabel would use around 96 Kib in memory compared to UILabel.

A single line text in a LCLabel would use around 384 Kib in memory compared to UILabel.

A single line with Emojis text in a LCLabel would use around 1.12 MiB in memory compared to the 1.23 MiB UILabel.

Scrolling

Using UILabel as a baseline, we were able to achieve a similar performance to UILabel, when scrolling and that was measured in the UI Full Tests. The benchmark was based on the amount of hitches detected on an iPhone XS, where both labels had zero hitches when scrolling a list around 5 times each time we ran the test.

License

LCLabel is MIT-licensed.

Disclaimer

UILabel and UITextView are Apple’s own components.