JonathanStorey

public struct PageView<Data, ID, Content>: View where Data: RandomAccessCollection, ID: Hashable, Content: View {
    
    let data: Data
    
    private let id: KeyPath<Data.Element, ID>
    
    @Binding private var selection: ID?
    
    private let content: (Data.Element) -> Content
    

JonathanStorey

//  Created by Jonathan Storey

// An extension for NavigationStack that mimics a page viewer. Perhaps most helpful for
// static type navigation where the series of pages has already been determined. In some
// circumstances this can replace the TabView (with PageTabViewStyle modifier). Supports
// the type-erased NavigationPath in addition to other Collection types. Added some
// safeguards to prevent crashes if the selection index is out of range.

// NavigationStack(pages: strings, selection: $index) { // strings are [String]
//     ...

JonathanStorey

/// A collection that supports moving and sorting of elements.
public protocol PermutableCollection: Collection {
    
    mutating func swapAt(_ i: Self.Index, _ j: Self.Index)
    
    // mutating func move(fromOffsets source: IndexSet, toOffset destination: Int)

    // mutating func partition(by belongsInSecondPartition: (Element) throws -> Bool) rethrows -> Index

}

JonathanStorey

struct KeyedList<Key, Element> : KeyableCollection { \\ ID or KEY... do I need ID???

    private var _elements: [Element]

    // init?()... if attempting to add elements, make init failable

    init(id keyPath: KeyPath<Element, Key>) where Key: Hashable {
    }
    
    init() where Element: Hashable, Key == Never { \\ ID == Self??

JonathanStorey

@propertyWrapper
struct NavigationState<Value>: DynamicProperty {

    @Shared private var path: Value

    var wrappedValue: Value {
        get { path }
        nonmutating set { path = newValue }
    }

JonathanStorey

struct ChildView: View {

    let text : String
    
    var body: some View {
    // THERE IS NO ACCESS TO THE PATH DATA!
...
}

JonathanStorey

struct ContentView: View {
    
    @NavigationState var path
    
    var body: some View {
        NavigationStack($path) {
     ...
}

struct ChildView: View {

JonathanStorey

typealias NavigationState = Shared<NavigationPath>

extension NavigationState where Value == NavigationPath {

    init(_ key: String? = nil) {
        self.init(wrappedValue: NavigationPath(), key)
    }

}

JonathanStorey

@propertyWrapper
class Observed<Value>: ObservableObject {
    
    @Published public var wrappedValue: Value

    public init(wrappedValue: Value) {
        self.wrappedValue = wrappedValue
    }
}

JonathanStorey

/// Dictionary-backed storage allowing for for single instantiation and retrieval of an object.
struct Singletons {
    
    private static var dictionary : [String : AnyObject] = [:]
    
    private static func key<T: AnyObject>(for type: T.Type, key: String? = nil) -> String {
        let type = String(reflecting: T.self) // describing: String; reflecting: Swift.String
        guard let key else { return type } // returns Swift.String
        return type + "." + key // returns Swift.String.key
    }