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input-remapper/keymapper/dev/injector.py

443 lines
15 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.config import config
from keymapper.getdevices import get_devices
from keymapper.state import system_mapping, KEYCODE_OFFSET
from keymapper.dev.macros import parse
DEV_NAME = 'key-mapper'
DEVICE_CREATED = 1
FAILED = 2
DEVICE_SKIPPED = 3
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'
return False
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(EV_KEY, evdev.ecodes.KEY_NUMLOCK, 1)
device.syn()
device.write(EV_KEY, evdev.ecodes.KEY_NUMLOCK, 0)
device.syn()
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)
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.
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.
"""
@ensure_numlock
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
"""
self.device = device
self.mapping = mapping
self._process = None
def __del__(self):
if self._process is not None:
self._process.terminate()
def start_injecting(self):
"""Start injecting keycodes."""
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."""
device = evdev.InputDevice(path)
if device is None:
return None
capabilities = device.capabilities(absinfo=False)
needed = False
if capabilities.get(EV_KEY) is not None:
for keycode, _ in self.mapping:
if keycode - KEYCODE_OFFSET in capabilities[EV_KEY]:
needed = True
break
can_do_abs = evdev.ecodes.ABS_X in capabilities.get(EV_ABS, [])
if self.map_abs_to_rel() and can_do_abs:
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
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
# 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
time.sleep(0.15)
return device
def map_abs_to_rel(self):
# TODO offer configuration via the UI if a gamepad is elected
return True
def _modify_capabilities(self, input_device):
"""Adds all keycode into a copy of a devices capabilities.
Prameters
---------
input_device : evdev.InputDevice
"""
ecodes = evdev.ecodes
# copy the capabilities because the keymapper_device is going
# to act like the device.
capabilities = input_device.capabilities(absinfo=False)
# Furthermore, support all injected keycodes
if len(self.mapping) > 0 and capabilities.get(ecodes.EV_KEY) is None:
capabilities[ecodes.EV_KEY] = []
for _, character in self.mapping:
keycode = system_mapping.get(character)
if keycode is not None:
capabilities[ecodes.EV_KEY].append(keycode - KEYCODE_OFFSET)
if self.map_abs_to_rel():
if capabilities.get(ecodes.EV_ABS):
del capabilities[ecodes.EV_ABS]
capabilities[ecodes.EV_REL] = [
evdev.ecodes.REL_X,
evdev.ecodes.REL_Y,
# for my system to recognize it as mouse, WHEEL is also needed:
evdev.ecodes.REL_WHEEL,
]
# 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]
return capabilities
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.
"""
# TODO do select.select insted of async_read_loop
loop = asyncio.get_event_loop()
coroutines = []
logger.info('Starting injecting the mapping for %s', self.device)
paths = get_devices()[self.device]['paths']
devices = [self._prepare_device(path) for path in paths]
# Watch over each one of the potentially multiple devices per hardware
for input_device in devices:
if input_device is None:
continue
# 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'key-mapper {self.device}',
phys='key-mapper',
events=self._modify_capabilities(input_device)
)
# keycode injection
coroutine = self._keycode_loop(input_device, uinput)
coroutines.append(coroutine)
# mouse movement injection
if self.map_abs_to_rel():
self.abs_x = 0
self.abs_y = 0
# events only take ints, so a movement of 0.3 needs to add
# up to 1.2 to affect the cursor.
self.pending_x_rel = 0
self.pending_y_rel = 0
coroutine = self._movement_loop(input_device, uinput)
coroutines.append(coroutine)
if len(coroutines) == 0:
logger.error('Did not grab any device')
return
loop.run_until_complete(asyncio.gather(*coroutines))
if len(coroutines) > 0:
logger.debug('asyncio coroutines ended')
def _write(self, device, type, keycode, value):
"""Actually inject."""
device.write(type, keycode, value)
device.syn()
def _macro_write(self, character, value, keymapper_device):
"""Handler for macros."""
keycode = system_mapping[character]
logger.spam(
'macro writes code:%s value:%d char:%s',
keycode, value, character
)
self._write(
keymapper_device,
EV_KEY,
keycode - KEYCODE_OFFSET,
value
)
async def _movement_loop(self, input_device, keymapper_device):
"""Keep writing mouse movements based on the gamepad stick position."""
logger.info('Mapping gamepad to mouse movements')
max_value = input_device.absinfo(EV_ABS).max
max_speed = ((max_value ** 2) * 2) ** 0.5
pointer_speed = config.get('gamepad.pointer_speed', 80)
non_linearity = config.get('gamepad.non_linearity', 4)
while True:
# this is part of the spawned process, so terminating that one
# will also stop this loop
await asyncio.sleep(1 / 60)
abs_y = self.abs_y
abs_x = self.abs_x
if non_linearity != 1:
# to make small movements smaller for more precision
speed = (abs_x ** 2 + abs_y ** 2) ** 0.5
factor = (speed / max_speed) ** non_linearity
else:
factor = 1
rel_x = abs_x * factor * pointer_speed / max_value
rel_y = abs_y * factor * pointer_speed / max_value
self.pending_x_rel += rel_x
self.pending_y_rel += rel_y
rel_x = int(self.pending_x_rel)
rel_y = int(self.pending_y_rel)
self.pending_x_rel -= rel_x
self.pending_y_rel -= rel_y
if rel_y != 0:
self._write(
keymapper_device,
EV_REL,
evdev.ecodes.ABS_Y,
rel_y
)
if rel_x != 0:
self._write(
keymapper_device,
EV_REL,
evdev.ecodes.ABS_X,
rel_x
)
async def _keycode_loop(self, device, keymapper_device):
"""Inject keycodes for one of the virtual devices.
Parameters
----------
device : evdev.InputDevice
where to read keycodes from
keymapper_device : evdev.UInput
where to write keycodes to
"""
# Parse all macros beforehand
logger.debug('Parsing macros')
macros = {}
for keycode, output in self.mapping:
if '(' in output and ')' in output and len(output) >= 4:
# probably a macro
macros[keycode] = parse(
output,
lambda *args: self._macro_write(*args, keymapper_device)
)
logger.debug(
'Started injecting into %s, fd %s',
keymapper_device.device.path, keymapper_device.fd
)
async for event in device.async_read_loop():
if self.map_abs_to_rel() and event.type == EV_ABS:
if event.code not in [evdev.ecodes.ABS_X, evdev.ecodes.ABS_Y]:
continue
if event.code == evdev.ecodes.ABS_X:
self.abs_x = event.value
if event.code == evdev.ecodes.ABS_Y:
self.abs_y = event.value
continue
if event.type != EV_KEY:
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
input_keycode = event.code + KEYCODE_OFFSET
character = self.mapping.get_character(input_keycode)
if character is None:
# unknown keycode, forward it
target_keycode = input_keycode
elif macros.get(input_keycode) is not None:
if event.value == 0:
continue
logger.spam(
'got code:%s value:%s, maps to macro %s',
event.code + KEYCODE_OFFSET,
event.value,
character
)
macro = macros.get(input_keycode)
if macro is not None:
asyncio.ensure_future(macro.run())
continue
else:
# TODO compile int-int mapping instead of going this route.
# I think that makes the reverse mapping obsolete.
target_keycode = system_mapping.get(character)
if target_keycode is None:
logger.error(
'Don\'t know what %s maps to',
character
)
continue
logger.spam(
'got code:%s value:%s, maps to code:%s char:%s',
event.code + KEYCODE_OFFSET,
event.value,
target_keycode,
character
)
self._write(
keymapper_device,
event.type,
target_keycode - KEYCODE_OFFSET,
event.value
)
# this should only ever happen in tests to avoid blocking them
# forever, as soon as all events are consumed. In normal operation
# there is no end to the events.
logger.error(
'The injector for "%s" stopped early',
keymapper_device.device.path
)
@ensure_numlock
def stop_injecting(self):
"""Stop injecting keycodes."""
logger.info('Stopping injecting keycodes for device "%s"', self.device)
if self._process is not None and self._process.is_alive():
self._process.terminate()