The directionality of the text.
This decides how textAlign values like TextAlign.start and TextAlign.end are interpreted.
This is also used to disambiguate how to render bidirectional text. For example, if the text is an English phrase followed by a Hebrew phrase, in a TextDirection.ltr context the English phrase will be on the left and the Hebrew phrase to its right, while in a TextDirection.rtl context, the English phrase will be on the right and the Hebrew phrase on its left.
Defaults to the ambient Directionality, if any.
final TextDirection? textDirection;