kCMTextMarkupAttribute_Alignment
The text alignment in the writing direction of the first line of text.
Declaration
let kCMTextMarkupAttribute_Alignment: CFStringDiscussion
This attribute’s value must be one of the constants listed below that indicate the alignment in the writing direction of the first line of text of the cue. The value (or absence) of the kCMTextMarkupAttribute_VerticalLayout attribute indicates the writing direction. The default value of this attribute is kCMTextMarkupAlignmentType_Middle.
If you use this attribute, apply it to the entire attributed string.