These constants describe the progression of text on a page. The typesetter decides which way text is supposed to flow and passes these values as arguments to the text container, which uses them to calculate the next line rectangle.
- macOS 10.0+
Line sweep is the direction text progresses within a line. See Text System Storage Layer Overview.
The only values currently used by the supplied typesetters are
NSText subclass should be prepared to deal with any value, and an
NSTypesetter subclass should be able to use any of them.