Returns the rectangle occupied by
a, which for this method is interpreted literally rather than as an indicator of scrolling direction.
- macOS 10.0+
NSScroller for a list of possible values for
Note the interpretations of
NSScroller. The actual part of an NSScroller that causes page-by-page scrolling varies, so as a convenience these part codes refer to useful parts different from the scroll buttons.
NSZero if the part requested isn’t present on the receiver.