onlock.py

from __future__ import print_function

import os, sys, pipes

import objc
from Foundation import NSObject

from CoreFoundation import (
    CFRunLoopRun, CFRunLoopStop, CFFileDescriptorCreate,
    CFFileDescriptorCreateRunLoopSource, CFRunLoopAddSource,
    kCFRunLoopDefaultMode, CFRunLoopGetCurrent,
    CFFileDescriptorEnableCallBacks, kCFFileDescriptorReadCallBack
)

from AppKit import NSNotificationCenter, NSDistributedNotificationCenter

class Locked(NSObject):
    @objc.selectorFor(NSNotificationCenter.addObserver_selector_name_object_)
    def observe_(self, notification):
        command = ' '.join(map(pipes.quote, sys.argv[1:]))
        print("Sleep: running ", command)
        os.system(command)

nsdnc = NSDistributedNotificationCenter.defaultCenter()
nsdnc.addObserver_selector_name_object_(
    Locked.alloc().init().retain(), "observe:", "com.apple.screenIsLocked",
    None,
)

def handle_signals():
    def stop(cffd, cbt, info):
        CFRunLoopStop(CFRunLoopGetCurrent())

    r, w = os.pipe()

    cffd = CFFileDescriptorCreate(None, r, False, stop, None)
    CFFileDescriptorEnableCallBacks(cffd, kCFFileDescriptorReadCallBack)
    cfrlsrc = CFFileDescriptorCreateRunLoopSource(None, cffd, 0)
    CFRunLoopAddSource(CFRunLoopGetCurrent(), cfrlsrc, kCFRunLoopDefaultMode)

    def nop(signum, stackframe):
        pass

    import signal
    signal.set_wakeup_fd(w)
    signal.signal(signal.SIGINT, nop)
    signal.signal(signal.SIGTERM, nop)

handle_signals()
CFRunLoopRun()

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