Android - Detect fragment moved from background to foreground

Question

Using the provided AppLifeCycleObserver shown below, you can ensure that LifecycleTransitionType.BACKGROUND_TO_FOREGROUND is triggered exclusively when the app transitions from the background to the foreground within the specific fragment where the observer is initialized. I want the observer to remain silent when you navigate to another fragment or open a new activity, ensuring that the observer's callback is invoked only for the intended transition from background to foreground within the fragment.

// Define an enumeration for different lifecycle transition types
enum class LifecycleTransitionType {
    FOREGROUND,              // Represents when the application or fragment is in the foreground
    BACKGROUND,              // Represents when the application or fragment is in the background
    BACKGROUND_TO_FOREGROUND // Represents the transition from background to foreground
}
// Create an AppLifeCycleObserver with a callback for handling lifecycle transitions
class AppLifeCycleObserver(private val listener: (LifecycleTransitionType) -> Unit) : DefaultLifecycleObserver {
    private var isApplicationInForeground = false
    private var isScreenInForeground = false
    private var previousState: LifecycleTransitionType? = null

    override fun onStart(owner: LifecycleOwner) {
        isScreenInForeground = true
        if (!isApplicationInForeground) {
            isApplicationInForeground = true
            // Notify the listener about the transition type based on the previous state
            if (previousState == LifecycleTransitionType.BACKGROUND) {
                listener(LifecycleTransitionType.BACKGROUND_TO_FOREGROUND)
            } else {
                listener(LifecycleTransitionType.FOREGROUND)
            }
            previousState =  LifecycleTransitionType.FOREGROUND
        }

        super.onStart(owner)
    }

    override fun onStop(owner: LifecycleOwner) {
        isScreenInForeground = false
        previousState = LifecycleTransitionType.BACKGROUND
        isApplicationInForeground = false

        super.onStop(owner)
    }
}

In the fragment:

// Define the AppLifeCycleObserver with a callback to handle transitions
val appLifecycleObserver = AppLifeCycleObserver { transitionType ->
    when (transitionType) {
        LifecycleTransitionType.BACKGROUND_TO_FOREGROUND -> {
            // Handle background-to-foreground transition here, specific to your fragment
            // You can put your logic to react to this transition
        }
        else -> {
            // Handle other lifecycle transitions if needed
        }
    }
}

// Attach the observer to the fragment's lifecycle
lifecycle.addObserver(appLifecycleObserver)

How can I refrain the observer from being called when a new activity or a fragment is opened?