It would be nice to have acceleration for the mouse wheel.
Report on Launchpad: https://bugs.launchpad.net/ubuntu/+source/meta-kde/+bug/619403
I am trying right now to implement this myself.
As I am not that used to the Xorg sources, this is what I want to do in xf86-input-mouse:
* Add some attributes in the _MouseDevRec struct (in fx86OSmouse.h) which are about the acceleration properties.
* In MouseCommonOptions in mouse.c, I am adding some additional handling to read those acceleration attributes.
* At some point in the input handling in mouse.c, add that acceleration handling (at what point exactly?). I plan to just throw out multiple button 4,5 press events.
Please give some comments about how to do it right.
Or probably it is better to add those properties to mousePrivRec (in mousePriv.h).
As far as X is concerned mouse wheel is a couple of buttons, so I'm not sure what acceleration would mean there. This sounds like it should be implemented in clients. In any case moving to evdev as you probably don't want to be doing that in the mouse driver anyway.
Ok, I am in the middle of a progress here. I am trying to optimise it a bit further. But I will attach my current progress so far so you can review it and give some comments because I actually have the problem that sometimes (mostly after I restart xinit on a running Xserver), somehow the device property names are messed up or at least xinput shows this:
az@acompneu 1275 (~) %xinput list-props 8
Device 'Microsoft Microsoft IntelliMouse® Explorer':
NumLock (119): 1
left_ptr (241): ... of unknown type _DBUS_SESSION_BUS_SELECTION_az_9797c07820e7488abd822c644c1f55a4
_DBUS_SESSION_BUS_ADDRESS (243): 0
_DBUS_SESSION_BUS_PID (244): 0
KDE_FULL_SESSION (245): ... of unknown type _DBUS_SESSION_BUS_SELECTION_az_9797c07820e7488abd822c644c1f55a4
KDE_SESSION_VERSION (246): ... of unknown type _DBUS_SESSION_BUS_SELECTION_az_9797c07820e7488abd822c644c1f55a4
WM_PROTOCOLS (247): ... of unknown type _DBUS_SESSION_BUS_SELECTION_az_9797c07820e7488abd822c644c1f55a4
Evdev Reopen Attempts (226): 10
Evdev Axis Inversion (227): 0, 0
Evdev Axes Swap (229): 0
_NET_WM_CONTEXT_HELP (251): "LevelFive" (127), "AltGr" (128)
_NET_WM_SYNC_REQUEST (252): "Alt" (120), "LevelThree" (121), "LAlt" (122), "RAlt" (123), "RControl" (124), "LControl" (125), "ScrollLock" (126), "_KDE_SPLASH_PROGRESS" (239), "WM_LOCALE_NAME" (240), "_XKB_RULES_NAMES" (238), "_XKB_RULES_NAMES" (238), "_XKB_RULES_NAMES" (238), "_XKB_RULES_NAMES" (238)
Evdev Middle Button Emulation (230): 2
Evdev Middle Button Timeout (231): 50
Evdev Wheel Emulation (232): 0
Evdev Wheel Emulation Axes (233): 0, 0, 4, 5
Evdev Wheel Emulation Inertia (234): 10
Evdev Wheel Emulation Timeout (235): 200
Evdev Wheel Emulation Button (236): 4
Evdev Drag Lock Buttons (237): 0
It looks a lot like some memory is messed up. I already tried to debug with valgrind but I didn't see anything related (a whole bunch of other messages show up there, so I also might have missed it).
Another thing which makes the debuggin a bit complicated: Most applications seem to scroll already for one event by multiple pixel; about 20 pixel in Chrome. And I have set it to the minimum possible value in the KDE settings (not sure if Chrome takes those or has its own settings). That makes the debugging quite hard because the scrolling is soon pretty much too fast.
Created attachment 38377 [details] [review]
mouse wheel acceleration patch - rev1
just added me to the CC. Sounds like a good idea to have acceleration.
Comment on attachment 38377 [details] [review]
mouse wheel acceleration patch - rev1
Note that this patch is already outdated. I have posted a new version to the mailinglist. I am not sure if I will keep updating the patch also here, so please watch out for the patch on the mailinglist.
good values to play with: speed-multiplier: 100, max-speed: 20
Created attachment 38386 [details] [review]
mouse wheel acceleration patch - rev2
Can you please send your patches to xorg-devel for review. Please rebase them
on top of current git master if appropriate. Thanks.
Don't work for xorg-server-1.11.4 :( Please fix it.
on Jun 26, 2016 at 20:46:11.
(provided by the Example extension).