Returns the first logical boundary rectangle for characters in the given range.
- macOS 10.5+
The character range whose boundary rectangle is returned.
NULL, contains the character range corresponding to the returned area if it was adjusted, for example, to a grapheme cluster boundary or characters in the first line fragment.
The boundary rectangle for the given range of characters, in screen coordinates. The rectangle’s
size value can be negative if the text flows to the left.
a spans multiple lines of text in the text view, the rectangle returned is the one surrounding the characters in the first line. In that case
actual contains the range covered by the first rect, so you can query all line fragments by invoking this method repeatedly. If the length of
a is 0 (as it would be if there is nothing selected at the insertion point), the rectangle coincides with the insertion point, and its width is 0.