#!/usr/bin/python3 # -*- coding: utf-8 -*- # key-mapper - GUI for device specific keyboard mappings # Copyright (C) 2020 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 re import asyncio import time import subprocess # By using processes instead of threads, the mappings are # automatically copied, so that they can be worked with in the ui # without breaking the device. And it's possible to terminate processes. import multiprocessing import evdev from keymapper.logger import logger from keymapper.getdevices import get_devices from keymapper.state import custom_mapping, system_mapping DEV_NAME = 'key-mapper' DEVICE_CREATED = 1 FAILED = 2 DEVICE_SKIPPED = 3 # offset between xkb and linux keycodes. linux keycodes are lower KEYCODE_OFFSET = 8 def _grab(path): """Try to grab, repeat a few times with time inbetween on failure.""" 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 logger.debug('Failed attemt to grab %s %d', path, attempts) if attempts >= 4: logger.error('Cannot grab %s, it is possibly in use', path) return None # it might take a little time until the device is free if # it was previously grabbed. time.sleep(0.15) return device def _modify_capabilities(device): """Adds all keycode into a copy of a devices capabilities.""" # copy the capabilities because the keymapper_device is going # to act like the device. capabilities = device.capabilities(absinfo=False) # However, make sure that it supports all keycodes, not just some # random ones, because the mapping could contain anything. # That's why I avoid from_device for this capabilities[evdev.ecodes.EV_KEY] = list(evdev.ecodes.keys.keys()) # just like what python-evdev does in from_device if evdev.ecodes.EV_SYN in capabilities: del capabilities[evdev.ecodes.EV_SYN] if evdev.ecodes.EV_FF in capabilities: del capabilities[evdev.ecodes.EV_FF] return capabilities def _is_device_mapped(device, mapping): """Check if this device has capabilities that are being mapped. Parameters ---------- device : evdev.InputDevice mapping : Mapping """ capabilities = device.capabilities(absinfo=False)[evdev.ecodes.EV_KEY] needed = False for keycode, _ in mapping: if keycode - KEYCODE_OFFSET in capabilities: needed = True if not needed: logger.debug('No need to grab %s', device.path) return needed def _start_injecting_worker(path, pipe, mapping): """Inject keycodes for one of the virtual devices. Parameters ---------- path : string path in /dev to read keycodes from pipe : multiprocessing.Pipe pipe to send status codes over """ # evdev needs asyncio to work loop = asyncio.new_event_loop() asyncio.set_event_loop(loop) try: device = _grab(path) except Exception as error: logger.error(error) pipe.send(FAILED) return if device is None: pipe.send(FAILED) return if not _is_device_mapped(device, mapping): # skipping reading and checking on events from those devices # may be beneficial for performance. pipe.send(DEVICE_SKIPPED) return keymapper_device = evdev.UInput( name=f'key-mapper {device.name}', phys='key-mapper', events=_modify_capabilities(device) ) pipe.send(DEVICE_CREATED) logger.debug( 'Started injecting into %s, fd %s', keymapper_device.device.path, keymapper_device.fd ) for event in device.read_loop(): if event.type != evdev.ecodes.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 = mapping.get_character(input_keycode) if character is None: # unknown keycode, forward it target_keycode = input_keycode else: target_keycode = system_mapping.get_keycode(character) if target_keycode is None: logger.error( 'Cannot find character %s in the internal mapping', character ) continue logger.spam( 'got code:%s value:%s, maps to code:%s char:%s', event.code + KEYCODE_OFFSET, event.value, target_keycode, character ) keymapper_device.write( evdev.ecodes.EV_KEY, target_keycode - KEYCODE_OFFSET, event.value ) keymapper_device.syn() 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(evdev.ecodes.EV_KEY, evdev.ecodes.KEY_NUMLOCK, 1) device.syn() device.write(evdev.ecodes.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.""" @ensure_numlock def __init__(self, device, mapping=custom_mapping): """Start injecting keycodes based on custom_mapping.""" self.device = device self.virtual_devices = [] self.processes = [] paths = get_devices()[self.device]['paths'] logger.info('Starting injecting the mapping for %s', self.device) # Watch over each one of the potentially multiple devices per hardware for path in paths: pipe = multiprocessing.Pipe() worker = multiprocessing.Process( target=_start_injecting_worker, args=(path, pipe[1], mapping) ) worker.start() # wait for the process to notify creation of the new injection # device, to keep the logs in order. status = pipe[0].recv() if status == DEVICE_CREATED: self.processes.append(worker) else: worker.join() if len(self.processes) == 0: raise OSError('Could not grab any device') @ensure_numlock def stop_injecting(self): """Stop injecting keycodes.""" logger.info('Stopping injecting keycodes for device %s', self.device) for i, process in enumerate(self.processes): if process is None: continue if process.is_alive(): process.terminate() self.processes[i] = None