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()
 	}