input-remapper/keymapper/injection/injector.py
2021-11-21 21:45:02 +01:00

428 lines
15 KiB
Python

#!/usr/bin/python3
# -*- coding: utf-8 -*-
# key-mapper - GUI for device specific keyboard mappings
# Copyright (C) 2021 sezanzeb <proxima@sezanzeb.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 asyncio
import time
import multiprocessing
import evdev
from evdev.ecodes import EV_KEY, EV_REL
from keymapper.logger import logger
from keymapper.groups import classify, GAMEPAD
from keymapper.mapping import DISABLE_CODE
from keymapper.injection.context import Context
from keymapper.injection.numlock import set_numlock, is_numlock_on, ensure_numlock
from keymapper.injection.consumer_control import ConsumerControl
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_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
def get_udev_name(name, suffix):
"""Make sure the generated name is not longer than 80 chars."""
max_len = 80 # based on error messages
remaining_len = max_len - len(DEV_NAME) - len(suffix) - 2
middle = name[:remaining_len]
name = f"{DEV_NAME} {middle} {suffix}"
return name
class Injector(multiprocessing.Process):
"""Initializes, starts and stops injections.
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 = 0.2
def __init__(self, group, mapping):
"""
Parameters
----------
group : _Group
the device group
mapping : Mapping
"""
self.group = group
self._state = UNKNOWN
# used to interact with the parts of this class that are running within
# the new process
self._msg_pipe = multiprocessing.Pipe()
self.mapping = mapping
self.context = None # only needed inside the injection process
self._consumer_controls = []
super().__init__()
"""Functions to interact with the running process"""
def get_state(self):
"""Get the state of the injection.
Can be safely called from the main process.
"""
# slowly figure out what is going on
alive = self.is_alive()
if self._state == UNKNOWN and not alive:
# didn't start yet
return self._state
# if it is alive, it is definitely at least starting up
if self._state == UNKNOWN and alive:
self._state = STARTING
# if there is a message available, it might have finished starting up
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
if self._state in [STARTING, RUNNING] and not alive:
self._state = FAILED
logger.error("Injector was unexpectedly found stopped")
return self._state
@ensure_numlock
def stop_injecting(self):
"""Stop injecting keycodes.
Can be safely called from the main procss.
"""
logger.info('Stopping injecting keycodes for group "%s"', self.group.key)
self._msg_pipe[1].send(CLOSE)
self._state = STOPPED
"""Process internal stuff"""
def _grab_devices(self):
"""Grab all devices that are needed for the injection."""
sources = []
for path in self.group.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
sources.append(source)
return sources
def _grab_device(self, path):
"""Try to grab the device, return None if not needed/possible.
Without grab, original events from it would reach the display server
even though they are mapped.
"""
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.context.mapping:
if is_in_capabilities(key, capabilities):
logger.debug('Grabbing "%s" because of "%s"', path, key)
needed = True
break
gamepad = classify(device) == GAMEPAD
if gamepad and self.context.maps_joystick():
logger.debug('Grabbing "%s" because of maps_joystick', path)
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:
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 >= 10:
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 _copy_capabilities(self, input_device):
"""Copy capabilities for a new device."""
ecodes = evdev.ecodes
# copy the capabilities because the uinput is going
# to act like the device.
capabilities = input_device.capabilities(absinfo=True)
# 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.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 symbols
capabilities[ecodes.EV_ABS].remove(ecodes.ABS_VOLUME)
return capabilities
def _construct_capabilities(self, 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
----------
gamepad : bool
If gamepad events can be translated to mouse events. (also
depends on the configured purpose)
Returns
-------
a mapping of int event type to an array of int event codes.
"""
ecodes = evdev.ecodes
capabilities = {EV_KEY: []}
# support all injected keycodes
for code in self.context.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 self.context.macros.values():
macro_capabilities = macro.get_capabilities()
for ev_type in macro_capabilities:
if len(macro_capabilities[ev_type]) == 0:
continue
if ev_type not in capabilities:
capabilities[ev_type] = []
capabilities[ev_type] += list(macro_capabilities[ev_type])
if gamepad and self.context.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)
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 run(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.
"""
# TODO run all injections in a single process via asyncio
# - Make sure that closing asyncio fds won't lag the service
# - SharedDict becomes obsolete
# - quick_cleanup needs to be able to reliably stop the injection
# - I think I want an event listener architecture so that macros,
# joystick_to_mouse, keycode_mapper and possibly other modules can get
# what they filter for whenever they want, without having to wire
# things through multiple other objects all the time
# - _new_event_arrived moves to the place where events are emitted. injector?
# - active macros and unreleased need to be per injection. it probably
# should move into the keycode_mapper class, but that only works if there
# is only one keycode_mapper per injection, and not per source. Problem was
# that I had to excessively pass around to which device to forward to...
# I also need to have information somewhere which source is a gamepad, I
# probably don't want to evaluate that from scratch each time `notify` is
# called.
# - benefit: writing macros that listen for events from other devices
logger.info('Starting injecting the mapping for "%s"', self.group.key)
# create a new event loop, because somehow running an infinite loop
# that sleeps on iterations (joystick_to_mouse) 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)
# create this within the process after the event loop creation,
# so that the macros use the correct loop
self.context = Context(self.mapping)
# grab devices as early as possible. If events appear that won't get
# released anymore before the grab they appear to be held down
# forever
sources = self._grab_devices()
if len(sources) == 0:
logger.error("Did not grab any device")
self._msg_pipe[0].send(NO_GRAB)
return
numlock_state = is_numlock_on()
coroutines = []
# where mapped events go to.
# See the Context docstring on why this is needed.
self.context.uinput = evdev.UInput(
name=get_udev_name(self.group.key, "mapped"),
phys=DEV_NAME,
events=self._construct_capabilities(GAMEPAD in self.group.types),
)
for source in sources:
# 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.
forward_to = evdev.UInput(
name=get_udev_name(source.name, "forwarded"),
phys=DEV_NAME,
events=self._copy_capabilities(source),
)
# actually doing things
consumer_control = ConsumerControl(self.context, source, forward_to)
coroutines.append(consumer_control.run())
self._consumer_controls.append(consumer_control)
coroutines.append(self._msg_listener())
# 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("Failed to run injector coroutines: %s", 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("Injector coroutines ended")
for source in sources:
# ungrab at the end to make the next injection process not fail
# its grabs
try:
source.ungrab()
except OSError as error:
# it might have disappeared
logger.debug("OSError for ungrab on %s: %s", source.path, str(error))