CTRubyAlignment.distributeSpace
Distributes the ruby text evenly over the width of the base text, adding space before the first and after the last character.
Declaration
case distributeSpaceDiscussion
If the width of the ruby text is less than the width of the base text, Core Text evenly distributes the ruby text over the width of the base text. A certain amount of space, usually half of the intercharacter width of the ruby text, appears before the first and after the last character.
If the width of the base text is less than the width of the ruby text, Core Text similarly aligns the base text to the width of the ruby text.