Uso de StateFlows para rastrear ubicación en aplicaciones Android

Creating efficient location management in an Android application involves more than just getting coordinates. A clear and logical architecture allows you to turn functionality on and off as needed, optimizing resource usage and improving the user experience. Here you will learn how to leverage StateFlows in conjunction with CoroutineScope to control location tracking effectively.

What is a StateFlow and how does it work in Android?

In Kotlin and Android, StateFlows have a special feature: they retain the last value emitted. This means that views can immediately access these values when connecting. Unlike Cold Flows, StateFlows keep the latest information secure and constantly available, ideal for real-time data such as location.

How can I use StateFlows to manage location?

Below is a basic example in Kotlin for defining a MutableStateFlow.

private val locationData  = MutableStateFlow(LocationData())val location  = locationData.asStateFlow()

Here you create a private MutableStateFlow to handle the information internally and then expose a more secure and controlled version to the rest of the application via asStateFlow().

In what way could you control the tracing with booleans?

Using boolean variables in MutableStateFlows allows you to determine when the application is active observing location changes and when it is paused.

Example in code:

private val isTracking  = MutableStateFlow(false)val tracking  = isTracking.asStateFlow()

In this way, it is easy to pause or reactivate tracking with simple assignments.

What is the difference between 'tracking' and 'observing location'?

It is important to distinguish clearly:

• isTracking is for specifically controlling when to pause or run tracking.
• isObservingLocation indicates whether all conditions are met, such as permissions enabled, to start location observing.

This approach provides clarity in identifying what aspect is affecting the proper functioning of the tracking.

How do I record the time since the start of the tracking?

To monitor how much time has elapsed since you started location observation, it is recommended to start another MutableStateFlow as shown:

private val elapsedTime  = MutableStateFlow(Duration.ZERO)val elapsed  = elapsedTime.asStateFlow()

Using this implementation, you can easily check and constantly display how long the operation has been running.

How to manage the start and end of the trace?

Dedicated functions to control each part of the process ensure clarity and order in your code:

• To activate the tracking:

fun startObservingLocation()  {  isObservingLocation.value  = true}

• To stop location observing:

fun stopObservingLocation()  {  isObservingLocation.value  = false}

• Completely terminate the operation (stopping observations and restoring initial data):

fun finishTracking()  {  stopObservingLocation()  setIsTracking(false)  elapsedTime.value  = Duration.ZERO  locationData.value  = LocationData()}

• To directly set whether tracking is active or not:

fun setIsTracking(isTracking: Boolean)  {  this.isTracking.value  = isTracking}

This structure ensures order and a clear division of responsibilities within your Android application.

Do you have doubts about how to apply these concepts in your current project? Leave us your question in the comments and we will continue learning together.