Regression introduced in 47df0e9eaa
Casting fullscreen_atom (which is the result from XInternAtom, i.e.
c_ulong) as i64 is obviously wrong -- the whole point of types such as
c_ulong is that long in C does *not* always have the same bit size...
Cast it as c_long instead.
While this is the most straightforward fix, I'm not sure it's the best
one: perhaps the x11 crate should offer a set_ulong() method along with
set_long(), which could be used here instead of the cast?
From the "Smooth Scrolling" section of [XI2Proto.txt][1]:
> One unit of scrolling in either direction is considered to be equivalent to
> one button event, e.g. for a unit size of 1.0, -2.0 on an valuator type
> Vertical sends two button press/release events for button 4. Likewise, a
> button press event for button 7 generates an event on the Horizontal
> valuator with a value of +1.0. The server may accumulate deltas of less than
> one unit of scrolling.
From [What's new in XI 2.1 - smooth scrolling][2]:
> The increment defines what delta the driver considers to be one scroll
> event. For an increment of +5, each delta of 5 should be regarded as one
> scroll unit down. For an increment of -3, each delta of 3 should be regarded
> as one scroll unit up (i.e. inverted).
[1]: http://www.x.org/releases/X11R7.7/doc/inputproto/XI2proto.txt
[2]: http://who-t.blogspot.com/2011/09/whats-new-in-xi-21-smooth-scrolling.html
This fixes scrolling with my Microsoft mouse in X11 on Debian 8.1.
fixes#314 for me.
I've "tested" change by running examples (which prior to change simply
crashed), but since I did not run those examples successfuly ever before,
I don't know whether they worked as intended.
XInput2 has a concept of master and slave devices,
where a slave device is the actual physical device,
attached to a master device representing the cursor or keyboard
focus.
See http://who-t.blogspot.co.uk/2009/05/xi2-recipes-part-1.html
Mouse events were being received from both the master and slave
devices, but we are only interested in events from the master device.
Fixes#533
