Get notified when workstation gets locked

Question

On Windows system pressing Win + L will lock the workstation. Is there a way within XUL addon detect when workstation is being locked down? I could probably detect pressing this key combination, but it would only work if XUL application in focus.

There is a sleep_notification available for when computer is going into sleep mode (or waking up). I can't find any information about locking workstation.

Answer 1

Found a way using js-ctypes (tested on Windows 10):

Components.utils.import("resource://gre/modules/ctypes.jsm");
var lib           = ctypes.open("user32.dll"),
    openDesktop   = lib.declare("OpenDesktopA", ctypes.winapi_abi, ctypes.uint32_t, ctypes.char.ptr, ctypes.uint32_t, ctypes.bool, ctypes.uint32_t),
    switchDesktop = lib.declare("SwitchDesktop", ctypes.winapi_abi, ctypes.bool, ctypes.uint32_t),
    closeDesktop  = lib.declare("CloseDesktop", ctypes.winapi_abi, ctypes.bool, ctypes.uint32_t),
    desktop       = openDesktop("Default", 0, 0, 0x0100),
    isUnLocked    = switchDesktop(desktop);

console.log(isUnLocked);//result false = locked, true = unlocked

closeDesktop(desktop);
lib.close();