psteiger

import kotlinx.coroutines.*
import kotlin.coroutines.*
import kotlin.system.*

/** Wraps original dispatcher, so we can wrap the continuations. */
class Monitor(
    private val interceptor: ContinuationInterceptor
) : AbstractCoroutineContextElement(ContinuationInterceptor), ContinuationInterceptor {
    override fun <T> interceptContinuation(continuation: Continuation<T>): Continuation<T> =
        interceptor.interceptContinuation(MeasuredContinuation(continuation))

psteiger

/**
 * Gates upstream flow emissions by [passThrough].
 *
 * When upstream flow emits a value, either emits the value downstream if the last value emitted by [passThrough]
 * was `true`, or accumulates it for later emission if `false`. Accumulated values are emitted once [passThrough]
 * emits `true`.
 */
@OptIn(FlowPreview::class) // produceIn is stable since kotlinx-coroutines 1.7.0-Beta
internal fun <T> Flow<T>.accumulateBy(passThrough: Flow<Boolean>) = flow<List<T>> {

psteiger

@Singleton
class Biller @Inject constructor(
    @ApplicationContext private val context: Context,
) : PurchasesUpdatedListener, BillingClientStateListener {
    
    private var billingClient: BillingClient =
        BillingClient.newBuilder(context)
            .setListener(this)
            .enablePendingPurchases()
            .build()

psteiger

@AndroidEntryPoint
class NearbyUsersActivity : AppCompatActivity() {
    
    private val viewModel: NearbyUsersViewModel by viewModels()
    
    override fun onCreate(savedInstanceState: Bundle?) {
        viewModel
            .locations
            .onEach { /* new locations received */ }
            .observeIn(this)

psteiger

@PublishedApi
internal class ObserverImpl<T> (
    lifecycleOwner: LifecycleOwner,
    private val flow: Flow<T>,
    private val collector: suspend (T) -> Unit
) : DefaultLifecycleObserver {

    private var job: Job? = null

    override fun onStart(owner: LifecycleOwner) {

psteiger

@Singleton
class NearbyUsersDataSource @Inject constructor() {
    // Ideally, those should be constructor-injected.
    val geoFire = GeoFire(FirebaseDatabase.getInstance().getReference("geofire"))
    val geoLocation = GeoLocation(0.0, 0.0)
    val radius = 100.0
    
    val geoQuery = geoFire.queryAtLocation(geoLocation, radius)
    
    private fun GeoQuery.asFlow() = callbackFlow {

psteiger

@AndroidEntryPoint
class NearbyUsersActivity : AppCompatActivity() {
    
    private val viewModel: NearbyUsersViewModel by viewModels()
    
    override fun onCreate(savedInstanceState: Bundle?) {
        lifecycleScope.launchWhenStarted {
            viewModel.locations.collect {
                // Update views with the data.   
            }

psteiger

@Singleton
class NearbyUsersDataSource @Inject constructor() {
    // Ideally, those should be constructor-injected.
    val geoFire = GeoFire(FirebaseDatabase.getInstance().getReference("geofire"))
    val geoLocation = GeoLocation(0.0, 0.0)
    val radius = 100.0
    
    val geoQuery = geoFire.queryAtLocation(geoLocation, radius)
    
    private fun GeoQuery.asFlow() = callbackFlow {

psteiger

@AndroidEntryPoint
class NearbyUsersActivity : AppCompatActivity() {
    
    private val viewModel: NearbyUsersViewModel by viewModels()
    
    override fun onCreate(savedInstanceState: Bundle?) {
        viewModel.locations.observe(this) { state: State ->
            // Update views with the data.   
        }
    }

psteiger

class NearbyUsersViewModel @ViewModelInject constructor(
    nearbyUsersRepository: NearbyUsersRepository
) : ViewModel() {

    val locations get() = nearbyUsersRepository.locations
}