missionControlActive.swift

#!/usr/bin/swift

// DETERMINE IF MISSION CONTROL IS CURRENTLY ACTIVE (tested on: Mojave, Monterey)
// • returns "true" (exit code 0) if Mission Control is active (all apps / single app / reveal desktop)
// • returns "false" (exit code 1) otherwise
// –––
// • uses hackish check for existence of title-less window owned by Apple's Dock process
//   • see: https://stackoverflow.com/a/66629065
// –––
// @frypf (Oct 2022)


import Cocoa


func missionControlActive() -> Bool {
	let windowList = CGWindowListCopyWindowInfo([.optionOnScreenOnly], kCGNullWindowID) as! [[String: Any]]
	for window in windowList {
		if
			// window must be owned by "Dock" process
			(window["kCGWindowOwnerName"] as? String) == "Dock",

			// ensure the owner is not some other process named "Dock" (seems unlikely though)
			let windowOwnerPID = window["kCGWindowOwnerPID"] as? pid_t,
			let app = NSRunningApplication(processIdentifier: windowOwnerPID),
			app.bundleIdentifier == "com.apple.dock",

			// window must have no title
			window["kCGWindowName"] == nil
		{
			return true
		}
	}
	return false
}

let result = missionControlActive()
print(result)
exit(result ? 0 : 1)