#!/usr/bin/python3 # -*- coding: utf-8 -*- # key-mapper - GUI for device specific keyboard mappings # Copyright (C) 2021 sezanzeb # # 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 . """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.getdevices import get_devices, is_gamepad from keymapper import utils from keymapper.mapping import DISABLE_CODE from keymapper.injection.keycode_mapper import KeycodeMapper from keymapper.injection.context import Context from keymapper.injection.event_producer import EventProducer from keymapper.injection.numlock import set_numlock, is_numlock_on, \ ensure_numlock 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 class Injector(multiprocessing.Process): """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): """Setup a process to 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._event_producer = None self._state = UNKNOWN self._msg_pipe = multiprocessing.Pipe() self.context = Context(mapping) 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 device "%s"', self.device) self._msg_pipe[1].send(CLOSE) self._state = STOPPED """Process internal stuff""" 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.context.mapping: if is_in_capabilities(key, capabilities): logger.debug('Grabbing "%s" because of "%s"', path, key) needed = True break gamepad = is_gamepad(device) 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: # 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 _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 characters 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(): capabilities[EV_KEY] += list(macro.get_capabilities()) 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. """ if self.device not in get_devices(): logger.error('Cannot inject for unknown device "%s"', self.device) return group = get_devices()[self.device] logger.info('Starting injecting the mapping for "%s"', self.device) # 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) self._event_producer = EventProducer(self.context) 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=f'{DEV_NAME} {self.device} mapped', phys=DEV_NAME, events=self._construct_capabilities(group['gamepad']) ) # Watch over each one of the potentially multiple devices per hardware for path in 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 # 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) forward_to = evdev.UInput( name=f'{DEV_NAME} {source.name} forwarded', phys=DEV_NAME, events=self._copy_capabilities(source) ) # actual reading of events coroutines.append(self._event_consumer(source, forward_to)) # 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.context.joystick_as_mouse(): self._event_producer.set_max_abs_from(source) 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') async def _event_consumer(self, source, forward_to): """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 ---------- source : evdev.InputDevice where to read keycodes from forward_to : evdev.UInput where to write keycodes to that were not mapped to anything. Should be an UInput with capabilities that work for all forwarded events, so ideally they should be copied from source. """ logger.debug( 'Started consumer to inject to %s, fd %s', source.path, source.fd ) gamepad = is_gamepad(source) keycode_handler = KeycodeMapper(self.context, source, forward_to) 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_as_btn(event, self.context.mapping, gamepad): 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 forward_to.write(event.type, event.code, event.value) # this already includes SYN events, so need to syn here again # This happens all the time in tests because the async_read_loop # stops when there is nothing to read anymore. Otherwise tests # would block. logger.error('The consumer for "%s" stopped early', source.path)