libinput/plugins/10-dwt.lua
Peter Hutterer 9e37bc0cfa plugins: add support for lua plugins to change evdev event streams
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>
2025-08-01 16:04:09 +10:00

40 lines
1.2 KiB
Lua

-- SPDX-License-Identifier: MIT
--
-- This plugin implements a very simple version of disable-while-typing.
-- It monitors all keyboard devices and if any of them send an event,
-- any touchpad device is disabled for 2 seconds.
-- And "disabled" means any event from that touchpad is simply
-- discarded.
--
-- Install this file in /etc/libinput/plugins and
--
-- UNCOMMENT THIS LINE TO ACTIVATE THE PLUGIN
-- libinput:register({1})
tp_enabled = true
libinput:connect("timer-expired", function(_, now)
log.debug("touchpad enabled")
tp_enabled = true
end)
libinput:connect("new-evdev-device", function (_, device)
local props = device:udev_properties()
if props.ID_INPUT_KEYBOARD then
device:connect("evdev-frame", function (_, _, _)
libinput:timer_set_relative(2000000)
if tp_enabled then
log.debug("touchpad disabled")
tp_enabled = false
end
end)
elseif props.ID_INPUT_TOUCHPAD then
log.debug("Touchpad detected: " .. device:name())
device:connect("evdev-frame", function (_, frame, _)
if not tp_enabled then
-- Returning an empty table discards the event.
return {}
end
end)
end
end)