mac toggle grayscale

toggle.swift

import Foundation

// Load the private framework
guard let handle = dlopen("/System/Library/PrivateFrameworks/UniversalAccess.framework/UniversalAccess", RTLD_NOW) else {
    fatalError("Unable to load UniversalAccess framework")
}

defer {
    dlclose(handle)
}

// Define function signatures
typealias UAGrayscaleIsEnabledFunc = @convention(c) () -> Bool
typealias UAGrayscaleSetEnabledFunc = @convention(c) (Bool) -> Void

// Load symbols
guard
    let isEnabledSym = dlsym(handle, "UAGrayscaleIsEnabled"),
    let setEnabledSym = dlsym(handle, "UAGrayscaleSetEnabled")
else {
    fatalError("Unable to load symbols")
}

// Cast to callable functions
let UAGrayscaleIsEnabled = unsafeBitCast(isEnabledSym, to: UAGrayscaleIsEnabledFunc.self)
let UAGrayscaleSetEnabled = unsafeBitCast(setEnabledSym, to: UAGrayscaleSetEnabledFunc.self)

// Toggle grayscale
let current = UAGrayscaleIsEnabled()
UAGrayscaleSetEnabled(!current)

print("Grayscale now: \(!current)")