How to use `.focusedSceneObject()` with @Observable?

The migration from .focusedSceneObject() to @Observable in SwiftUI can be achieved by using a @State property to store the focused value and then binding the focused property of the view to this @State property. Here's how you can migrate from .focusedSceneObject() to @Observable:

1. Define an @Observable Property:

   Create an @Observable property that will store the focused value. This property can be of any appropriate data type, such as a String or a custom struct. For example:

   @Observable var focusedValue: String = ""
   

2. Bind focused to the @Observable Property:

   Instead of using .focusedSceneObject(), you can bind the focused property of a view to your @Observable property using the $ syntax. This allows you to set and get the focused value.

   For example, if you were using .focusedSceneObject() like this:

   .focusedSceneObject(\.focusedValue)
   

   You can migrate it to @Observable like this:

   .focused($focusedValue)
   

   This binding connects the view's focus state to the focusedValue property.

3. Update Usage of the Focused Value:

   Wherever you were using .focusedSceneObject(\.focusedValue), you can now use the focusedValue property directly.

   For example, if you had a Text view displaying the focused value:

   Text("Focused Value: \(focusedValue)")
   

   This code will still work with the focusedValue property defined in step 1.

By following these steps, you can migrate from .focusedSceneObject() to @Observable while maintaining the functionality of managing the focused value in your SwiftUI view.

I'm just migrating some ObservedObjects to Observable and ran into this problem with a Commands menu with a FocusedObject dependency. I want some entries in the menu to be enabled and to act on state from the Observable object.

What finally worked for me (so far) is using a FocusedValues extension. I couldn't get this to work without the key path API, despite what the documentation says, and there doesn't appear to be a single example on the Internet.

struct MyFocusedObservableStateValue: FocusedValueKey {
    typealias Value = MyObservableStateType
}

extension FocusedValues {
    var myObservableState: MyFocusedObservableStateValue.Value? {
        get { self[MyFocusedObservableStateValue.self] }
        set { self[MyFocusedObservableStateValue.self] = newValue }
    }
}

struct ItemActionsCommandMenu: Commands {
    @FocusedValue(\.myObservableState) var myObservableState

    var body: some Commands {
        CommandMenu("Menu Name") {
             // use myObservableState as needed (Note: It's optional)
             Button("Action") {
             }
             .disabled(...)
         }
    }
}

Elsewhere in App:

myContentView
  .focusedSceneValue(\.myObservableState, myObservableState)