input-remapper/keymapper/dev/injector.py
2021-02-07 22:16:41 +01:00

579 lines
19 KiB
Python

#!/usr/bin/python3
# -*- coding: utf-8 -*-
# key-mapper - GUI for device specific keyboard mappings
# Copyright (C) 2021 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_REL
from keymapper.logger import logger
from keymapper.getdevices import get_devices, is_gamepad
from keymapper.dev.keycode_mapper import KeycodeMapper
from keymapper.dev import utils
from keymapper.dev.event_producer import EventProducer
from keymapper.dev.macros import parse, is_this_a_macro
from keymapper.state import system_mapping
from keymapper.mapping import DISABLE_CODE
from keymapper.config import NONE, MOUSE, WHEEL
DEV_NAME = 'key-mapper'
# messages
CLOSE = 0
OK = 1
# states
UNKNOWN = -1
STARTING = 2
FAILED = 3
RUNNING = 4
STOPPED = 5
# for both states and messages
NO_GRAB = 6
def is_numlock_on():
"""Get the current state of the numlock."""
try:
xset_q = subprocess.check_output(
['xset', 'q'],
stderr=subprocess.STDOUT
).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 Injector:
"""Keeps injecting events in the background based on mapping and config.
Is a process to make it non-blocking for the rest of the code and to
make running multiple injector easier. There is one process 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._state = UNKNOWN
self._event_producer = None
def _forwards_joystick(self):
"""If at least one of the joysticks remains a regular joystick."""
left_purpose = self.mapping.get('gamepad.joystick.left_purpose')
right_purpose = self.mapping.get('gamepad.joystick.right_purpose')
return NONE in (left_purpose, right_purpose)
def _maps_joystick(self):
"""If at least one of the joysticks will serve a special purpose."""
left_purpose = self.mapping.get('gamepad.joystick.left_purpose')
right_purpose = self.mapping.get('gamepad.joystick.right_purpose')
return (left_purpose, right_purpose) != (NONE, NONE)
def _joystick_as_mouse(self):
"""If at least one joystick maps to an EV_REL capability."""
purposes = (
self.mapping.get('gamepad.joystick.left_purpose'),
self.mapping.get('gamepad.joystick.right_purpose')
)
return MOUSE in purposes or WHEEL in purposes
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._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._state = STARTING
self._process = multiprocessing.Process(target=self._start_injecting)
self._process.start()
def get_state(self):
"""Get the state of the injection."""
# only at this point the actual state is figured out
if self._state == STARTING and self._msg_pipe[1].poll():
msg = self._msg_pipe[1].recv()
if msg == OK:
self._state = RUNNING
if msg == NO_GRAB:
self._state = NO_GRAB
alive = self._process is not None and self._process.is_alive()
if self._state in [STARTING, RUNNING] and not alive:
self._state = FAILED
logger.error('Injector was unexpectedly found stopped')
return self._state
def _grab_device(self, path):
"""Try to grab the device, return None if not needed/possible."""
try:
device = evdev.InputDevice(path)
except (FileNotFoundError, OSError):
logger.error('Could not find "%s"', path)
return None
capabilities = device.capabilities(absinfo=False)
needed = False
for key, _ in self.mapping:
if is_in_capabilities(key, capabilities):
needed = True
break
gamepad = is_gamepad(device)
if gamepad and self._maps_joystick():
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:
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 as error:
attempts += 1
# it might take a little time until the device is free if
# it was previously grabbed.
logger.debug('Failed attempts to grab %s: %d', path, attempts)
if attempts >= 4:
logger.error('Cannot grab %s, it is possibly in use', path)
logger.error(str(error))
return None
time.sleep(self.regrab_timeout)
return device
def _modify_capabilities(self, macros, input_device, gamepad):
"""Adds all used keycodes into a copy of a devices capabilities.
Sometimes capabilities are a bit tricky and change how the system
interprets the device.
Parameters
----------
macros : dict
mapping of int to _Macro
input_device : evdev.InputDevice
gamepad : bool
if ABS capabilities should be removed in favor of REL
Returns
-------
a mapping of int event type to an array of int event codes.
Without absinfo.
"""
ecodes = evdev.ecodes
# copy the capabilities because the uinput is going
# to act like the device.
capabilities = input_device.capabilities(absinfo=False)
if (self._key_to_code or macros) and 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 gamepad and self._joystick_as_mouse():
# 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 gamepad and not self._forwards_joystick():
# Key input to text inputs and such only works without ABS
# events in the capabilities, possibly due to some intentional
# constraints in wayland/X. So if the joysticks are not used
# as joysticks remove ABS.
del capabilities[ecodes.EV_ABS]
if ecodes.ABS_VOLUME in capabilities.get(ecodes.EV_ABS, []):
# For some reason an ABS_VOLUME capability likes to appear
# for some users. It prevents mice from moving around and
# keyboards from writing characters
capabilities[ecodes.EV_ABS].remove(ecodes.ABS_VOLUME)
return capabilities
async def _msg_listener(self):
"""Wait for messages from the main process to do special stuff."""
loop = asyncio.get_event_loop()
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.
Use this function as starting point in a process. It creates
the loops needed to read and map events and keeps running them.
"""
# create a new event loop, because somehow running an infinite loop
# that sleeps on iterations (event_producer) 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()
coroutines = []
logger.info('Starting injecting the mapping for "%s"', self.device)
paths = get_devices()[self.device]['paths']
self._event_producer = EventProducer(self.mapping)
# Watch over each one of the potentially multiple devices per hardware
for path in paths:
source = self._grab_device(path)
if source is None:
# this path doesn't need to be grabbed for injection, because
# it doesn't provide the events needed to execute the mapping
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.
gamepad = is_gamepad(source)
uinput = evdev.UInput(
name=f'{DEV_NAME} {self.device}',
phys=DEV_NAME,
events=self._modify_capabilities(macros, source, gamepad)
)
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)
# actual reading of events
coroutines.append(self._event_consumer(macros, source, uinput))
# The event source of the current iteration will deliver events
# that are needed for this. It is that one that will be mapped
# to a mouse-like devnode.
if gamepad and self._joystick_as_mouse():
self._event_producer.set_max_abs_from(source)
self._event_producer.set_mouse_uinput(uinput)
if len(coroutines) == 0:
logger.error('Did not grab any device')
self._msg_pipe[0].send(NO_GRAB)
return
coroutines.append(self._msg_listener())
# run besides this stuff
coroutines.append(self._event_producer.run())
# set the numlock state to what it was before injecting, because
# grabbing devices screws this up
set_numlock(numlock_state)
self._msg_pipe[0].send(OK)
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:
# expected when stop_injecting is called,
# during normal operation as well as tests this point is not
# reached otherwise.
logger.debug('asyncio coroutines ended')
def _macro_write(self, code, value, uinput):
"""Handler for macros."""
logger.spam('macro writes %s', (EV_KEY, code, value))
uinput.write(EV_KEY, code, value)
uinput.syn()
async def _event_consumer(self, macros, source, uinput):
"""Reads input events to inject keycodes or talk to the event_producer.
Can be stopped by stopping the asyncio loop. This loop
reads events from a single device only. Other devnodes may be
present for the hardware device, in which case this needs to be
started multiple times.
Parameters
----------
macros : 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
"""
logger.debug(
'Started consumer to inject to %s, fd %s',
source.path, source.fd
)
keycode_handler = KeycodeMapper(
source, self.mapping, uinput,
self._key_to_code, macros
)
async for event in source.async_read_loop():
if self._event_producer.is_handled(event):
# the event_producer will take care of it
self._event_producer.notify(event)
continue
# for mapped stuff
if utils.should_map_event_as_btn(event, self.mapping):
will_report_key_up = utils.will_report_key_up(event)
keycode_handler.handle_keycode(
event,
)
if not will_report_key_up:
# simulate a key-up event if no down event arrives anymore.
# this may release macros, combinations or keycodes.
release = evdev.InputEvent(0, 0, event.type, event.code, 0)
self._event_producer.debounce(
debounce_id=(event.type, event.code, event.value),
func=keycode_handler.handle_keycode,
args=(
release,
False
),
ticks=3,
)
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 consumer for "%s" stopped early',
source.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._state = STOPPED