FusedLocationProviderClient.locationFlow

FusedLocationProviderClientUtils.kt

// Send location updates to the consumer 
fun FusedLocationProviderClient.locationFlow() = callbackFlow<Location> {
  // A new Flow is created. This code executes in a coroutine!

  // 1. Create callback and add elements into the flow
  val callback = object : LocationCallback() {
    override fun onLocationResult(result: LocationResult?) {
      result ?: return // Ignore null responses
      for (location in result.locations) {
        try {
          offer(location) // Send location to the flow
        } catch (t: Throwable) {
          // Location couldn't be sent to the flow 
        }
      }
    }
  }

  // 2. Register the callback to get location updates by calling requestLocationUpdates
  requestLocationUpdates(
    createLocationRequest(),
    callback,
    Looper.getMainLooper()
  ).addOnFailureListener { e ->
    close(e) // in case of error, close the Flow
  }

  // 3. Wait for the consumer to cancel the coroutine and unregister
  // the callback. This suspends the coroutine until the Flow is closed.
  awaitClose {
    // Clean up code goes here
    removeLocationUpdates(callback)
  }
}