This patch adds support for Lua scripts to modify evdev devices and
event frames before libinput sees those events.
Plugins in Lua are sandboxed and restricted in what they can do: no IO,
no network, not much of anything else.
A plugin is notified about a new device before libinput handles it and
it can thus modify that device (changes are passed through to our libevdev
context). A plugin can then also connect an evdev frame handler which
gives it access to the evdev frames before libinput processes them. The
example plugin included shows how to swap left/right mouse buttons:
libinput:register({1})
function frame(device, frame)
for _, v in ipairs(frame.events) do
if v.usage == evdev.BTN_RIGHT then
v.usage = evdev.BTN_LEFT
elseif v.usage == evdev.BTN_LEFT then
v.usage = evdev.BTN_RIGHT
end
end
return frame
end
function device_new(plugin, device)
local usages = device:usages()
if usages[evdev.BTN_LEFT] and usages[evdev.BTN_RIGHT] then
device:connect("evdev-frame", frame)
end
end
libinput:connect("new-evdev-device", device_new)
A few other example plugins are included in this patch
Part-of: <https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/1192>
