ControllerAction.swift

import SwiftUI

struct ControllerActionPrefereneceKey: PreferenceKey {
    static let defaultValue: [ControllerAction] = []
    static func reduce(value: inout [ControllerAction], nextValue: () -> [ControllerAction]) {
        value.append(contentsOf: nextValue())
    }
}

struct ControllerActionModifier: ViewModifier {
    @Namespace var id
    var title: String
    var perform: () -> ()
    var enabled: Bool
    func body(content: Content) -> some View {
        content
            .transformPreference(ControllerActionPrefereneceKey.self, { arr in
                arr.append(.init(id: id, enabled: enabled, title: title, perform: perform))
            })
    }
}

extension View {
    func action(_ name: String, enabled: Bool = true, perform: @escaping () -> ()) -> some View {
        modifier(ControllerActionModifier(title: name, perform: perform, enabled: enabled))
    }
}

struct ControllerAction: Identifiable, Equatable {
    var id: Namespace.ID
    var title: String
    var enabled: Bool
    var perform: () -> ()
    init(id: Namespace.ID, enabled: Bool, title: String, perform: @escaping () -> Void) {
        self.id = id
        self.title = title
        self.perform = perform
        self.enabled = enabled
    }

    static func == (lhs: ControllerAction, rhs: ControllerAction) -> Bool {
        // The `perform` closure is never compared and should always be the same closure
        lhs.id == rhs.id && lhs.title == rhs.title && lhs.enabled == rhs.enabled
    }
}