FB9856587

README.md

Given a NSTextContentStorage with a single character \n (newline), a layout manager results in 2 line fragments.

Two things to discuss here:

1. The range of a second TextLineFragment is {1, 0}, that is 0 length range, yet the textLineFragment.attributedString.string value is "\n"
2. Why two lines at all? I expected a single line. this seems to be a case only if \n is at the end of the storage string. The string "\n\n\n" results in 3 fragments, and 4 lines.

last_line_fragments.swift

import Cocoa

let layoutManager = NSTextLayoutManager()
layoutManager.textContainer = NSTextContainer(containerSize: NSSize(width: 800, height: 500))

let textStorage = NSTextContentStorage()
textStorage.attributedString = NSAttributedString(string: "\n")
textStorage.addTextLayoutManager(layoutManager)

layoutManager.enumerateTextLayoutFragments(from: nil, options: .ensuresLayout, using: { fragment in
    print("line fragments: \(fragment.textLineFragments.count)")
    
    for (idx, textLineFragment) in fragment.textLineFragments.enumerated() {
        print("\(idx + 1). \(textLineFragment.characterRange) string: \(textLineFragment.attributedString.string.map(\.unicodeScalars))")
    }
    return true
})

// line fragments: 2
// 1. {0, 1} string: [StringUnicodeScalarView("\n")]
// 2. {1, 0} string: [StringUnicodeScalarView("\n")]