input-remapper/keymapper/injector.py
2020-11-22 13:58:56 +01:00

261 lines
8.1 KiB
Python

#!/usr/bin/python3
# -*- coding: utf-8 -*-
# key-mapper - GUI for device specific keyboard mappings
# Copyright (C) 2020 sezanzeb <proxima@hip70890b.de>
#
# This file is part of key-mapper.
#
# key-mapper is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# key-mapper is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with key-mapper. If not, see <https://www.gnu.org/licenses/>.
"""Keeps injecting keycodes in the background based on the mapping."""
import re
import asyncio
import time
import subprocess
# By using processes instead of threads, the mappings are
# automatically copied, so that they can be worked with in the ui
# without breaking the device. And it's possible to terminate processes.
import multiprocessing
import evdev
from keymapper.logger import logger
from keymapper.getdevices import get_devices
from keymapper.state import custom_mapping, system_mapping
DEV_NAME = 'key-mapper'
DEVICE_CREATED = 1
FAILED = 2
def _grab(path):
"""Try to grab, repeat a few times with time inbetween on failure."""
attempts = 0
while True:
device = evdev.InputDevice(path)
try:
# grab to avoid e.g. the disabled keycode of 10 to confuse
# X, especially when one of the buttons of your mouse also
# uses 10. This also avoids having to load an empty xkb
# symbols file to prevent writing any unwanted keys.
device.grab()
break
except IOError:
attempts += 1
logger.debug('Failed attemt to grab %s %d', path, attempts)
if attempts >= 4:
logger.error('Cannot grab %s', path)
return None
# it might take a little time until the device is free if
# it was previously grabbed.
time.sleep(0.15)
return device
def _modify_capabilities(device):
"""Adds all keycode into a copy of a devices capabilities."""
# copy the capabilities because the keymapper_device is going
# to act like the device.
capabilities = device.capabilities(absinfo=False)
# However, make sure that it supports all keycodes, not just some
# random ones, because the mapping could contain anything.
# That's why I avoid from_device for this
capabilities[evdev.ecodes.EV_KEY] = list(evdev.ecodes.keys.keys())
# just like what python-evdev does in from_device
if evdev.ecodes.EV_SYN in capabilities:
del capabilities[evdev.ecodes.EV_SYN]
if evdev.ecodes.EV_FF in capabilities:
del capabilities[evdev.ecodes.EV_FF]
return capabilities
def _start_injecting_worker(path, pipe, mapping):
"""Inject keycodes for one of the virtual devices.
Parameters
----------
path : string
path in /dev to read keycodes from
pipe : multiprocessing.Pipe
pipe to send status codes over
"""
# evdev needs asyncio to work
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
device = _grab(path)
if device is None:
pipe.send(FAILED)
return
capabilities = _modify_capabilities(device)
keymapper_device = evdev.UInput(
name=f'key-mapper {device.name}',
phys='key-mapper',
events=capabilities
)
pipe.send(DEVICE_CREATED)
logger.debug(
'Started injecting into %s, fd %s',
device.path, keymapper_device.fd
)
for event in device.read_loop():
if event.type != evdev.ecodes.EV_KEY:
logger.spam(
'got type:%s code:%s value:%s, forward',
event.type, event.code, event.value
)
keymapper_device.write(event.type, event.code, event.value)
# this already includes SYN events, so need to syn here again
continue
if event.value == 2:
# linux does them itself, no need to trigger them
continue
# this happens to report key codes that are 8 lower
# than the ones reported by xev and that X expects
input_keycode = event.code + 8
character = mapping.get_character(input_keycode)
if character is None:
# unknown keycode, forward it
target_keycode = input_keycode
else:
target_keycode = system_mapping.get_keycode(character)
if target_keycode is None:
logger.error(
'Cannot find character %s in the internal mapping',
character
)
continue
logger.spam(
'got code:%s value:%s, maps to code:%s char:%s',
event.code + 8, event.value, target_keycode, character
)
keymapper_device.write(
evdev.ecodes.EV_KEY,
target_keycode - 8,
event.value
)
keymapper_device.syn()
def is_numlock_on():
"""Get the current state of the numlock."""
xset_q = subprocess.check_output(['xset', 'q']).decode()
num_lock_status = re.search(
r'Num Lock:\s+(.+?)\s',
xset_q
)
if num_lock_status is not None:
return num_lock_status[1] == 'on'
def toggle_numlock():
"""Turn the numlock on or off."""
try:
subprocess.check_output(['numlockx', 'toggle'])
except FileNotFoundError:
# doesn't seem to be installed everywhere
logger.debug('numlockx not found, trying to inject a keycode')
# and this doesn't always work.
device = evdev.UInput(
name=f'key-mapper numlock-control',
phys='key-mapper',
)
device.write(evdev.ecodes.EV_KEY, evdev.ecodes.KEY_NUMLOCK, 1)
device.syn()
device.write(evdev.ecodes.EV_KEY, evdev.ecodes.KEY_NUMLOCK, 0)
device.syn()
def ensure_numlock(func):
def wrapped(*args, **kwargs):
# for some reason, grabbing a device can modify the num lock state.
# remember it and apply back later
numlock_before = is_numlock_on()
result = func(*args, **kwargs)
numlock_after = is_numlock_on()
if numlock_after != numlock_before:
logger.debug('Reverting numlock status to %s', numlock_before)
toggle_numlock()
return result
return wrapped
class KeycodeInjector:
"""Keeps injecting keycodes in the background based on the mapping."""
@ensure_numlock
def __init__(self, device, mapping=custom_mapping):
"""Start injecting keycodes based on custom_mapping."""
self.device = device
self.virtual_devices = []
self.processes = []
paths = get_devices()[self.device]['paths']
logger.info(
'Starting injecting the mapping for %s on %s',
self.device,
', '.join(paths)
)
# Watch over each one of the potentially multiple devices per hardware
for path in paths:
pipe = multiprocessing.Pipe()
worker = multiprocessing.Process(
target=_start_injecting_worker,
args=(path, pipe[1], mapping)
)
worker.start()
# wait for the process to notify creation of the new injection
# device, to keep the logs in order.
status = pipe[0].recv()
if status != FAILED:
self.processes.append(worker)
else:
worker.join()
if len(self.processes) == 0:
raise OSError('Could not grab any device')
@ensure_numlock
def stop_injecting(self):
"""Stop injecting keycodes."""
logger.info('Stopping injecting keycodes for device %s', self.device)
for i, process in enumerate(self.processes):
if process is None:
continue
if process.is_alive():
process.terminate()
self.processes[i] = None