The tracking for the text.
- iOS 10.0+
- macOS 10.12+
- Mac Catalyst 13.0+
- tvOS 10.0+
- watchOS 3.0+
- Core Text
The value associated with this attribute must be a CFNumber float. The default is
0 (no tracking).
Tracking adds space, in points, between the specified character cluster. A positive value increases the spacing between characters, while a negative value brings the characters closer together. For example, setting
k to 0.1 adds 0.1 point of spacing between each character of the text.
The effect of this attribute is similar to
k, but it treats tracking as trailing whitespace and a nonzero amount disables nonessential ligatures, unless overridden by the presence of