Re: XInput 2 support

[Po Lu]

Alan Third <alan@idiocy.org> writes:

> I think it's definitely worth it.

Thanks!

> it could never directly support multitouch and pixel-scrolling without
> adding XInput2 support and that I wasn't confident enough to do that
> myself.

BTW, the attached version of the change should make it easier for
someone to add pixelwise scrolling support in the future.

Basically, the pixel-wise delta you want is the `delta' in the following
code snippet:

    double delta =
      x_get_scroll_valuator_delta (dpyinfo, xev->deviceid,
                                   i, *values, &val);

0001-Add-support-for-event-processing-via-XInput-2.patch
Description: Text Data

A pain point with this code is how the Lisp-side mwheel code assumes
that the wheel event will always be mouse-4 to 8 under X, so the code
tries to emulate the legacy Core Input behaviour instead of generating
WHEEL_EVENTs.  To properly support XInput 2 scrolling, mwheel.el will
have to be modified to support using both kinds of events under the same
session.