input-remapper/keymapper/dev/injector.py
2021-01-01 22:20:33 +01:00

490 lines
16 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
import multiprocessing
import evdev
from evdev.ecodes import EV_KEY, EV_ABS, EV_REL
from keymapper.logger import logger
from keymapper.getdevices import get_devices, map_abs_to_rel
from keymapper.dev.keycode_mapper import handle_keycode, \
should_map_event_as_btn
from keymapper.dev.ev_abs_mapper import ev_abs_mapper, JOYSTICK
from keymapper.dev.macros import parse, is_this_a_macro
from keymapper.state import system_mapping
from keymapper.mapping import DISABLE_CODE
DEV_NAME = 'key-mapper'
CLOSE = 0
def is_numlock_on():
"""Get the current state of the numlock."""
try:
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'
return False
except subprocess.CalledProcessError:
# tty
return None
def set_numlock(state):
"""Set the numlock to a given state of True or False."""
if state is None:
return
value = {
True: 'on',
False: 'off'
}[state]
try:
subprocess.check_output(['numlockx', value])
except subprocess.CalledProcessError:
# might be in a tty
pass
except FileNotFoundError:
# doesn't seem to be installed everywhere
logger.debug('numlockx not found')
def ensure_numlock(func):
"""Decorator to reset the numlock to its initial state afterwards."""
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)
set_numlock(numlock_before)
return result
return wrapped
def is_in_capabilities(key, capabilities):
"""Are this key or one of its sub keys in the capabilities?
Parameters
----------
key : Key
"""
for sub_key in key:
if sub_key[1] in capabilities.get(sub_key[0], []):
return True
return False
class KeycodeInjector:
"""Keeps injecting keycodes in the background based on the mapping.
Is a process to make it non-blocking for the rest of the code and to
make running multiple injector easier. There is one procss per
hardware-device that is being mapped.
"""
regrab_timeout = 0.5
def __init__(self, device, mapping):
"""Start injecting keycodes based on custom_mapping.
Parameters
----------
device : string
the name of the device as available in get_device
mapping : Mapping
"""
self.device = device
self.mapping = mapping
self._process = None
self._msg_pipe = multiprocessing.Pipe()
self._key_to_code = self._map_keys_to_codes()
self.stopped = False
# when moving the joystick and then staying at a position, no
# events will be written anymore. Remember the last value the
# joystick reported, because it is still remaining at that
# position.
self.abs_state = [0, 0, 0, 0]
def _map_keys_to_codes(self):
"""To quickly get target keycodes during operation.
Returns a mapping of one or more 3-tuples to ints.
Examples:
((1, 2, 1),): 3
((1, 5, 1), (1, 4, 1)): 4
"""
key_to_code = {}
for key, output in self.mapping:
if is_this_a_macro(output):
continue
target_code = system_mapping.get(output)
if target_code is None:
logger.error('Don\'t know what %s is', output)
continue
for permutation in key.get_permutations():
if permutation.keys[-1][-1] not in [-1, 1]:
logger.error(
'Expected values to be -1 or 1 at this point: %s',
permutation.keys
)
key_to_code[permutation.keys] = target_code
return key_to_code
def start_injecting(self):
"""Start injecting keycodes."""
if self.stopped or self._process is not None:
# So that there is less concern about integrity when putting
# stuff into self. Each injector object can only be
# started once.
raise Exception('Please construct a new injector instead')
if self.device not in get_devices():
logger.error('Cannot inject for unknown device "%s"', self.device)
return
self._process = multiprocessing.Process(target=self._start_injecting)
self._process.start()
def _prepare_device(self, path):
"""Try to grab the device, return if not needed/possible.
Also return if ABS events are changed to REL mouse movements,
because the capabilities of the returned device are changed
so this cannot be checked later anymore.
"""
try:
device = evdev.InputDevice(path)
except FileNotFoundError:
return None, False
capabilities = device.capabilities(absinfo=False)
needed = False
for key, _ in self.mapping:
if is_in_capabilities(key, capabilities):
needed = True
break
abs_to_rel = map_abs_to_rel(capabilities)
if abs_to_rel:
needed = True
if not needed:
# skipping reading and checking on events from those devices
# may be beneficial for performance.
logger.debug('No need to grab %s', path)
return None, False
attempts = 0
while True:
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()
logger.debug('Grab %s', path)
break
except IOError:
attempts += 1
# it might take a little time until the device is free if
# it was previously grabbed.
logger.debug('Failed attemts to grab %s: %d', path, attempts)
if attempts >= 4:
logger.error('Cannot grab %s, it is possibly in use', path)
return None, False
time.sleep(self.regrab_timeout)
return device, abs_to_rel
def _modify_capabilities(self, macros, input_device, abs_to_rel):
"""Adds all used keycodes into a copy of a devices capabilities.
A device with those capabilities can do exactly the stuff it needs
to perform all mappings and macros.
Prameters
---------
macros : dict
maping of int to _Macro
input_device : evdev.InputDevice
abs_to_rel : bool
if ABS capabilities should be removed in favor of REL
"""
ecodes = evdev.ecodes
# copy the capabilities because the uinput is going
# to act like the device.
capabilities = input_device.capabilities(absinfo=False)
if len(self._key_to_code) > 0 or len(macros) > 0:
if capabilities.get(EV_KEY) is None:
capabilities[EV_KEY] = []
# Furthermore, support all injected keycodes
for code in self._key_to_code.values():
if code == DISABLE_CODE:
continue
if code not in capabilities[EV_KEY]:
capabilities[EV_KEY].append(code)
# and all keycodes that are injected by macros
for macro in macros.values():
capabilities[EV_KEY] += list(macro.get_capabilities())
if abs_to_rel:
# REL_WHEEL was also required to recognize the gamepad
# as mouse, even if no joystick is used as wheel.
capabilities[EV_REL] = [
evdev.ecodes.REL_X,
evdev.ecodes.REL_Y,
evdev.ecodes.REL_WHEEL,
evdev.ecodes.REL_HWHEEL,
]
if capabilities.get(EV_KEY) is None:
capabilities[EV_KEY] = []
if ecodes.BTN_MOUSE not in capabilities[EV_KEY]:
# to be able to move the cursor, this key capability is
# needed
capabilities[EV_KEY].append(ecodes.BTN_MOUSE)
# just like what python-evdev does in from_device
if ecodes.EV_SYN in capabilities:
del capabilities[ecodes.EV_SYN]
if ecodes.EV_FF in capabilities:
del capabilities[ecodes.EV_FF]
if ecodes.EV_ABS in capabilities:
# EV_KEY events are ignoerd by the os when EV_ABS capabilities
# are present
del capabilities[ecodes.EV_ABS]
return capabilities
async def _msg_listener(self, loop):
"""Wait for messages from the main process to do special stuff."""
while True:
frame_available = asyncio.Event()
loop.add_reader(self._msg_pipe[0].fileno(), frame_available.set)
await frame_available.wait()
frame_available.clear()
msg = self._msg_pipe[0].recv()
if msg == CLOSE:
logger.debug('Received close signal')
# stop the event loop and cause the process to reach its end
# cleanly. Using .terminate prevents coverage from working.
loop.stop()
return
def _start_injecting(self):
"""The injection worker that keeps injecting until terminated.
Stuff is non-blocking by using asyncio in order to do multiple things
somewhat concurrently.
"""
# create a new event loop, because somehow running an infinite loop
# that sleeps on iterations (ev_abs_mapper) in one process causes
# another injection process to screw up reading from the grabbed
# device.
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
numlock_state = is_numlock_on()
loop = asyncio.get_event_loop()
coroutines = []
logger.info('Starting injecting the mapping for "%s"', self.device)
paths = get_devices()[self.device]['paths']
# Watch over each one of the potentially multiple devices per hardware
for path in paths:
source, abs_to_rel = self._prepare_device(path)
if source is None:
continue
# each device needs own macro instances to add a custom handler
logger.debug('Parsing macros for %s', path)
macros = {}
for key, output in self.mapping:
if is_this_a_macro(output):
macro = parse(output, self.mapping)
if macro is None:
continue
for permutation in key.get_permutations():
macros[permutation.keys] = macro
if len(macros) == 0:
logger.debug('No macros configured')
# certain capabilities can have side effects apparently. with an
# EV_ABS capability, EV_REL won't move the mouse pointer anymore.
# so don't merge all InputDevices into one UInput device.
uinput = evdev.UInput(
name=f'{DEV_NAME} {self.device}',
phys=DEV_NAME,
events=self._modify_capabilities(macros, source, abs_to_rel)
)
logger.spam(
'Injected capabilities for "%s": %s',
path, uinput.capabilities(verbose=True)
)
def handler(*args, uinput=uinput):
# this ensures that the right uinput is used for macro_write,
# because this is within a loop
self._macro_write(*args, uinput)
for macro in macros.values():
macro.set_handler(handler)
# keycode injection
coroutine = self._keycode_loop(macros, source, uinput, abs_to_rel)
coroutines.append(coroutine)
# mouse movement injection
if abs_to_rel:
self.abs_state[0] = 0
self.abs_state[1] = 0
coroutine = ev_abs_mapper(
self.abs_state,
source,
uinput,
self.mapping
)
coroutines.append(coroutine)
if len(coroutines) == 0:
logger.error('Did not grab any device')
return
coroutines.append(self._msg_listener(loop))
# set the numlock state to what it was before injecting, because
# grabbing devices screws this up
set_numlock(numlock_state)
try:
loop.run_until_complete(asyncio.gather(*coroutines))
except RuntimeError:
# stopped event loop most likely
pass
except OSError as error:
logger.error(str(error))
if len(coroutines) > 0:
logger.debug('asyncio coroutines ended')
def _macro_write(self, code, value, uinput):
"""Handler for macros."""
logger.spam('macro writes code:%s value:%d', code, value)
uinput.write(EV_KEY, code, value)
uinput.syn()
async def _keycode_loop(self, macros, source, uinput, abs_to_rel):
"""Inject keycodes for one of the virtual devices.
Can be stopped by stopping the asyncio loop.
Parameters
----------
macros : (int, int) -> _Macro
macro with a handler that writes to the provided uinput
source : evdev.InputDevice
where to read keycodes from
uinput : evdev.UInput
where to write keycodes to
abs_to_rel : bool
if joystick events should be mapped to mouse movements
"""
logger.debug(
'Started injecting into %s, fd %s',
uinput.device.path, uinput.fd
)
async for event in source.async_read_loop():
if should_map_event_as_btn(source, event, self.mapping):
handle_keycode(
self._key_to_code,
macros,
event,
uinput
)
continue
if abs_to_rel and event.type == EV_ABS and event.code in JOYSTICK:
if event.code == evdev.ecodes.ABS_X:
self.abs_state[0] = event.value
elif event.code == evdev.ecodes.ABS_Y:
self.abs_state[1] = event.value
elif event.code == evdev.ecodes.ABS_RX:
self.abs_state[2] = event.value
elif event.code == evdev.ecodes.ABS_RY:
self.abs_state[3] = event.value
continue
# forward the rest
uinput.write(event.type, event.code, event.value)
# this already includes SYN events, so need to syn here again
logger.error(
'The injector for "%s" stopped early',
uinput.device.path
)
@ensure_numlock
def stop_injecting(self):
"""Stop injecting keycodes."""
logger.info('Stopping injecting keycodes for device "%s"', self.device)
self._msg_pipe[1].send(CLOSE)
self.stopped = True