Sets the size at which the given glyph (assumed to be an attachment) is asked to draw in the given glyph range.
- iOS 7.0+
- macOS 10.0+
- tvOS 9.0+
The glyph size to set.
The attachment glyph’s position in the glyph stream.
For a glyph corresponding to an attachment, this method should be called to set the size for the attachment cell to occupy. The glyph's value should be
This method is used by the layout mechanism and should be invoked only during typesetting, in almost all cases only by the typesetter. For example, a custom typesetter might invoke it.