foot-switch-driver

#!/bin/python

import usb
import subprocess
import time
import json

# Put:
# SUBSYSTEMS=="usb", ATTRS{idVendor}=="0c45", ATTRS{idProduct}=="7403", GROUP="users",
# MODE="0666"
# In:
# /etc/udev/rules.d/50-embedded_devices.rules

# Execute a lua script in awesome
def run_awesome(cmd):
    p = subprocess.Popen(
        ['awesome-client'],
        stdin=subprocess.PIPE,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
    )
    out = p.communicate(input=cmd)
    if out[1]:
        raise Exception(out[1])

    type, result = out[0].decode().strip().partition(' ')[::2]

    if type == 'string':
        result = result[1:-1]

    return result


# Get the currently focused client class name
def get_focused_client():
    return run_awesome(rb'''
return client.focus.class
''')

# Send events to X (see xte --help)
def send_x_events(*keys):
    subprocess.check_call(['xte'] + list(keys))


def on_keydown():
    res = run_awesome(rb'''
pedal_focused_client = nil
pedal_new_client = nil
local awful = require("awful")
for i, c in pairs(client.get()) do
    if c.class == "Chromium" or c.class == "chromium-continuous-bin" or c.class == "chromium" then
        pedal_focused_client = client.focus
        pedal_new_client = c
        awful.client.jumpto(c)
        return
    end
end
return "not found"
''')
    if res != 'not found':
        time.sleep(.1)
        send_x_events('key F5')

def on_keyup():
    run_awesome(rb'''
local awful = require("awful")
if pedal_new_client == client.focus and pedal_focused_client ~= nil then
    awful.client.jumpto(pedal_focused_client)
end
''')

vendor_id = 0x0c45
device_id = 0x7403

try:
    device = usb.core.find(idVendor=vendor_id, idProduct=device_id)
    if device is None:
        raise Exception('device not found')

    try:
        device.detach_kernel_driver(0)
    except:
        pass

    usb.util.claim_interface(device, 0)

    while True:
        data = device.read(0x81, 8, 0)

        if data[3]:
            on_keydown()
        else:
            on_keyup()

finally:
    if device:
        usb.util.release_interface(device, 0)

foot-switch-driver.service

[Unit]
Description=Foot switch driver

[Service]
ExecStart=/opt/bin/foot-switch-driver
Restart=always

[Install]
WantedBy=multi-user.target