vds_ios/VDS/Protocols/Changeable.swift

//
//  Changeable.swift
//  VDS
//
//  Created by Matt Bruce on 4/3/23.
//

import Foundation
import UIKit
import Combine

public protocol Changeable: ViewProtocol where Self: UIControl {
    /// Sets the primary Subscriber used for the UIControl event .valueChanged.
    var onChangeSubscriber: AnyCancellable? { get set }
}

extension Changeable {
    /// Allows the setting of a completion block against the onChangeSubscriber cancellable.  This will
    /// completion block will get executed against the UIControl publisher for the 'valueChange' action.
    public var onChange: ((Self) -> ())? {
        get { return nil }
        set {
            onChangeSubscriber?.cancel()
            if let newValue {
                onChangeSubscriber = publisher(for: .valueChanged)
                    .sink { c in
                        newValue(c)
                    }
            } else {
                onChangeSubscriber = nil 
            }
            setNeedsUpdate()
        }
    }
}