When the MLTE function TXNNewObject creates a text object, MLTE creates other structures that maintain information about the styles and attributes of the text associated with a text object.
MLTE keeps track of character attributes as runs. A run is a sequence of characters that are contiguous in memory and share a set of common attributes.
MLTE has two functions your application can use to get or set text attributes. Attributes are passed to and from these functions in a type attributes structure. This structure supports your application's use of ATSUI font features and font variations, should you want to use them.
A font feature is the set of typographic and layout characteristics that creates a specific appearance for a glyph. For example, displaying text as small caps is a font feature. A font variation is a range of typestyles along a variation axis . For example, a "width" font variation allows your application to condense or expand a line of displayed text. If you want to get or set such ASTUI font features or variations, your application can pass ATSUI font features or variations information in the type attributes structure.