The threshold controlling when hyphenation is done.
- iOS 7.0–13.0Deprecated
- macOS 10.0–10.15Deprecated
- tvOS 9.0–13.0Deprecated
Whenever (width of the real contents of the line) / (the line fragment width) is below
factor, hyphenation is attempted when laying out the line. Hyphenation slows down text layout and increases memory usage, so it should be used sparingly.