Markus Stange [:mstange] Reporter
	Description • 10 years ago

Mac OS 10.6 has non-overlay scrollbars, and if we want the scrollbar thumb to move, we need to repaint the whole scrollbar. Scrollbar painting is only possible on the main thread at the moment.

If we want to be able to move the scrollbar thumb with an asynchronous transform on the compositor in response to async scrolling, we need to think of a solution for 10.6 style scrollbars.
Maybe that solution is to force overlay scrollbars on 10.6 users.

	Florian Bender
	Comment 1 • 10 years ago

There's also more "traditional" scrollbars when you plug in a mouse or set a system pref (under "General"). Is this different from the 10.6 scrollbars (excluding minor style tweaks).

	Markus Stange [:mstange] Reporter
	Comment 2 • 10 years ago

The non-overlay scrollbars in 10.7 and up can probably be split into separate items for the track and the thumb. I think we're going to need that splitting for bug 989768 anyway.

	Milan Sreckovic [:milan] (needinfo for best results)
	Comment 3 • 10 years ago

I'm not sure we want to do special work for 10.6, even if that means leaving 10.6 with synchronous panning.

	Markus Stange [:mstange] Reporter
	Comment 4 • 10 years ago

Sounds good to me.

(In reply to Markus Stange [:mstange] from comment #2)
> The non-overlay scrollbars in 10.7 and up can probably be split into
> separate items for the track and the thumb. I think we're going to need that
> splitting for bug 989768 anyway.

Bug 1016569 implements the splitting.

	Florian Bender
	Comment 5 • 10 years ago

I guess this bug is WONTFIX then?

	Kartikaya Gupta (email:kats@mozilla.staktrace.com)
	Comment 6 • 9 years ago

WONTFIXing based on discussion above. We can leave APZ disabled on 10.6 if it comes to that.