Reflect 'new' ability to middle-click on GtkRange (scrollbars, scales, etc.), other scrolling features
Submitted by Daniel Boles
The recent fix for this GTK+ bug:
expanded on the mouse actions available on GtkRange derived widgets, by making middle-clicking do the opposite of the action configured by the “gtk-primary-button-warps-slider” GtkSetting:
It would be nice to mention this in mouse-middleclick.page.
Also, I didn't look far into it yet, but if there's not currently much info about what users can do with their mouse on ranges, or in terms of scrolling more generally, it would be good to expand on those topics too.
For the former, the GtkSettings documentation could be adapted; for the latter, this is a good overview of how things currently are.
(Now, let's just not talk about horizontal scrolling on ranges, until Bug 788905 is fixed...)