Fix for freeze in MenuBarExtra and NavigationStack (#158)

Sources/Defaults/SwiftUI.swift

@@ -6,25 +6,39 @@ extension Defaults {
  final class Observable<Value: Serializable>: ObservableObject {
  private var cancellable: AnyCancellable?
  private var task: Task<Void, Never>?
- private let key: Defaults.Key<Value>
-
- let objectWillChange = ObservableObjectPublisher()
+
+ var key: Defaults.Key<Value> {
+ didSet {
+ if key != oldValue {
+ observe()
+ }
+ }
+ }
 
  var value: Value {
  get { Defaults[key] }
  set {
- objectWillChange.send()
  Defaults[key] = newValue
  }
  }
 
  init(_ key: Key<Value>) {
  self.key = key
-
+
+ observe()
+ }
+
+ deinit {
+ task?.cancel()
+ }
+
+ func observe() {
  // We only use this on the latest OSes (as of adding this) since the backdeploy library has a lot of bugs.
  if #available(macOS 13, iOS 16, tvOS 16, watchOS 9, *) {
+ task?.cancel()
+
  // The `@MainActor` is important as the `.send()` method doesn't inherit the `@MainActor` from the class.
- self.task = .detached(priority: .userInitiated) { @MainActor [weak self] in
+ task = .detached(priority: .userInitiated) { @MainActor [weak self, key] in
  for await _ in Defaults.updates(key) {
  guard let self else {
  return
@@ -34,7 +48,7 @@ extension Defaults {
  }
  }
  } else {
- self.cancellable = Defaults.publisher(key, options: [.prior])
+ cancellable = Defaults.publisher(key, options: [.prior])
  .sink { [weak self] change in
  guard change.isPrior else {
  return
@@ -47,10 +61,6 @@ extension Defaults {
  }
  }
 
- deinit {
- task?.cancel()
- }
-
  /**
  Reset the key back to its default value.
  */
@@ -71,8 +81,7 @@ public struct Default<Value: Defaults.Serializable>: DynamicProperty {
 
  private let key: Defaults.Key<Value>
 
- // Intentionally using `@ObservedObjected` over `@StateObject` so that the key can be dynamically changed.
- @ObservedObject private var observable: Defaults.Observable<Value>
+ @StateObject private var observable: Defaults.Observable<Value>
 
  /**
  Get/set a `Defaults` item and also have the view be updated when the value changes. This is similar to `@State`.
@@ -99,7 +108,7 @@ public struct Default<Value: Defaults.Serializable>: DynamicProperty {
  */
  public init(_ key: Defaults.Key<Value>) {
  self.key = key
- self.observable = .init(key)
+ self._observable = .init(wrappedValue: .init(key))
  }
 
  public var wrappedValue: Value {
@@ -122,6 +131,7 @@ public struct Default<Value: Defaults.Serializable>: DynamicProperty {
  public var publisher: Publisher { Defaults.publisher(key) }
 
  public mutating func update() {
+ observable.key = key
  _observable.update()
  }