Python script to emulate media keys on mac

media-keys.py

#!/opt/homebrew/bin/python3

# CLI program to control the mediakeys on OS X. Used to emulate the mediakey on a keyboard with no such keys.
# Easiest used in combination with a launcher/trigger software such as Quicksilver.
# Main part taken from http://stackoverflow.com/questions/11045814/emulate-media-key-press-on-mac
# Glue to make it into cli program by Fredrik Wallner http://www.wallner.nu/fredrik/
# requires installing `pyobjc` eg via `/opt/homebrew/bin/pip3 install -U pyobjc`

import Quartz
import sys

# NSEvent.h
NSSystemDefined = 14

# hidsystem/ev_keymap.h
NX_KEYTYPE_SOUND_UP = 0
NX_KEYTYPE_SOUND_DOWN = 1
NX_KEYTYPE_PLAY = 16
NX_KEYTYPE_NEXT = 17
NX_KEYTYPE_PREVIOUS = 18
NX_KEYTYPE_FAST = 19
NX_KEYTYPE_REWIND = 20

supportedcmds = {'playpause': NX_KEYTYPE_PLAY,
                 'next': NX_KEYTYPE_NEXT,
                 'prev': NX_KEYTYPE_PREVIOUS,
                 'volup': NX_KEYTYPE_SOUND_UP,
                 'voldown': NX_KEYTYPE_SOUND_DOWN}


def HIDPostAuxKey(key):
    def doKey(down):
        ev = Quartz.NSEvent.otherEventWithType_location_modifierFlags_timestamp_windowNumber_context_subtype_data1_data2_(
            NSSystemDefined,  # type
            (0, 0),  # location
            0xa00 if down else 0xb00,  # flags
            0,  # timestamp
            0,  # window
            0,  # ctx
            8,  # subtype
            (key << 16) | ((0xa if down else 0xb) << 8),  # data1
            -1  # data2
            )
        cev = ev.CGEvent()
        Quartz.CGEventPost(0, cev)
    doKey(True)
    doKey(False)


if __name__ == "__main__":
    try:
        command = sys.argv[1]
        assert (command in supportedcmds)
        HIDPostAuxKey(supportedcmds[command])
    except (IndexError, AssertionError):
        print("Usage: %s command" % (sys.argv[0],))
        print("\tSupported commands are %s" % supportedcmds.keys())