Static kCTFrameProgressionAttributeName 

pub unsafe static kCTFrameProgressionAttributeName: &'static CFString

Available on crate feature CTFrame only.

Specifies progression for a frame.

Value must be a CFNumberRef containing a CTFrameProgression. Default is kCTFrameProgressionTopToBottom. This value determines the line stacking behavior for a frame and does not affect the appearance of the glyphs within that frame.

See also: CTFramesetterCreateFrame

See also Apple’s documentation