Wrap.swift

import AppKit
import SwiftUI

// MARK: Wrap

public struct Wrap<Wrapped: NSView>: NSViewRepresentable {
    private var makeView: () -> Wrapped
    private var update: (Wrapped, Context) -> Void

    public init(_ makeView: @escaping @autoclosure () -> Wrapped,
                updater update: @escaping (Wrapped, Context) -> Void) {
        self.makeView = makeView
        self.update = update
    }

    public init(_ makeView: @escaping @autoclosure () -> Wrapped,
                updater update: @escaping (Wrapped) -> Void) {
        self.makeView = makeView
        self.update = { view, _ in update(view) }
    }

    public init(_ makeView: @escaping @autoclosure () -> Wrapped) {
        self.makeView = makeView
        update = { _, _ in }
    }

    public func makeNSView(context: Context) -> Wrapped {
        makeView()
    }

    public func updateNSView(_ view: Wrapped, context: Context) {
        update(view, context)
    }
}

// MARK: WrapController

public struct WrapController<Wrapped: NSViewController>: NSViewControllerRepresentable {
    private var makeView: () -> Wrapped
    private var update: (Wrapped, Context) -> Void

    public init(_ makeView: @escaping @autoclosure () -> Wrapped,
                updater update: @escaping (Wrapped, Context) -> Void) {
        self.makeView = makeView
        self.update = update
    }

    public init(_ makeView: @escaping @autoclosure () -> Wrapped,
                updater update: @escaping (Wrapped) -> Void) {
        self.makeView = makeView
        self.update = { view, _ in update(view) }
    }

    public init(_ makeView: @escaping @autoclosure () -> Wrapped) {
        self.makeView = makeView
        update = { _, _ in }
    }

    public func makeNSViewController(context: Context) -> Wrapped {
        makeView()
    }

    public func updateNSViewController(_ nsViewController: Wrapped, context: Context) {
        update(nsViewController, context)
    }
}