I'm seeing more, but ultimately, all of
.ScrollBox's scripts manipulate
.ScrollBar, which fires an
OnScroll event through its inherited CallbackRegistry. The event fires with the scroll percent, so you don't need to fetch it yourself.
Lua Code:
local ScrollBar=AchievementFrameAchievements.ScrollBar;
ScrollBar:RegisterCallback(ScrollBar.Event.OnScroll,function(_,scrollpercent)
print(scrollpercent);
end);
Sources of note:
ScrollUtil.InitScrollFrameWithScrollBar() - SharedXML/Scroll/ScrollUtil.lua:197
ScrollBarMixin:SetScrollPercentage() & ScrollBarMixin:SetScrollPercentageInternal() - SharedXML/Scroll/ScrollBar.lua:163 & 180