NSControl Publisher

controlpublisher.swift

import Cocoa
import Combine

class ControlPublisher<T: NSControl>: Publisher {

    typealias Control = NSControl
    typealias Output = Control
    typealias Failure = Never

    let subject = PassthroughSubject<Output, Failure>()

    init(control: NSControl) {
        control.target = self
        control.action = #selector(controlAction)
    }

    @objc private func controlAction(sender: NSControl) {
        subject.send(sender)
    }

    func receive<S>(subscriber: S) where S :
        Subscriber,
        ControlPublisher.Failure == S.Failure,
        ControlPublisher.Output == S.Input {

            subject.receive(subscriber: subscriber)
    }
}