NS port and fancy OS X scrollbars

[Alan Third]

I was reading through Anders's wish-list for the NS port and noticed
the bit about implementing the new OS X 'floating' scroll bars. As I'd
been looking at scrollbars for a bug report anyway I figured I'd try
to work out what would be required.

As far as I can tell the 'right' way to do it is to create an
NSScrollView and put your buffer content into another NSView within
it. This seems to give you native scrollbars for a lot less work than
is being done at the moment. However I think we'd lose the ability to
put the vertical scrollbars on the left. I don't know how important
that feature is.

I think there's a bigger problem, though. It looks to me like the mode
line is currently drawn into the same NSView as the rest of the
buffer, so just wrapping the current NSView with an NSScrollView would
result in the vertical scrollbar overlapping the mode line, and the
horizontal scrollbar below it.

Am I right about this? If so then it seems the only way to get the
floating scrollbars would be to recreate the effect ourselves, which I
suspect is rather a lot of work.
-- 
Alan Third