Analyse the output of `xinput test-xi2 --root` for key press/release events

analyse_log.py

#!/usr/bin/env python3

import itertools
import re
import sys

try:
    from plover.oslayer.xkeyboardcontrol import KEYCODE_TO_KEY
except ImportError:
    print('error: could not import plover.oslayer.xkeyboardcontrol.KEYCODE_TO_KEY, '
          'will print raw key codes instead of key names', file=sys.stderr)
    KEYCODE_TO_KEY = {}


class LogAnalyser(object):

    def __init__(self, input_device_name=None):
        self.keys = set()
        self.event = {}
        self.input_device_id = set()
        self.input_device_name = input_device_name
        self.xtest_keyboard_id = None

    def process_event(self):
        if not self.event:
            return
        event_type = self.event.get('type')
        if event_type not in ('KeyPress', 'KeyRelease'):
            return
        event_device_id = self.event['device'].split()[0]
        if event_device_id == self.xtest_keyboard_id:
            return
        if event_device_id != (self.input_device_id or event_device_id):
            return
        event_detail = self.event['detail']
        key_name = KEYCODE_TO_KEY.get(int(event_detail), event_detail)
        if event_type == 'KeyPress':
            event_type = 'press'
            self.keys.add(key_name)
        else:
            event_type = 'release'
            self.keys.discard(key_name)
        print('%-10s %-10s %s' % (event_type, key_name, '+'.join(sorted(self.keys))))

    def analyze(self, input):
        self.keys = set()
        self.event = {}
        for line in itertools.chain(input, ['']):
            line = line.strip()
            m = re.search('↳ (.*)\s+id=(\d+)', line)
            if m is not None:
                device_name = m.group(1).strip()
                device_id = m.group(2)
                if device_name == 'Virtual core XTEST keyboard':
                    print('XTEST keyboard device:', device_id)
                    self.xtest_keyboard_id = device_id
                elif device_name == self.input_device_name:
                    print(self.input_device_name + ':', device_id)
                    self.input_device_id.add(device_id)
            m = re.match('^EVENT .* \((\w+)\)$', line)
            if m is not None:
                self.process_event()
                self.event = {'type': m.group(1)}
                continue
            if not line:
                self.process_event()
                self.event = {}
                continue
            m = re.match('^(\w+):(.*)$', line)
            if m is not None:
                self.event[m.group(1)] = m.group(2).strip()
                continue


if __name__ == '__main__':

    if len(sys.argv) > 1:
        input_filename = sys.argv[1]
    else:
        input_filename = '-'
    if input_filename == '-':
        input = sys.stdin
    else:
        input = open(input_filename)
    if len(sys.argv) > 2:
        input_device_name = sys.argv[2]
    else:
        input_device_name = None

    analyser = LogAnalyser(input_device_name)
    analyser.analyze(input)