psteiger

@Singleton
class NearbyUsersRepository @Inject constructor(
    nearbyUsersDataSource: NearbyUsersDataSource
) {
    val locations get() = nearbyUsersDataSource.locations
}

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@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)
    
    // Listener for receiving GeoLocations

psteiger

suspend fun requestLocationPermissions(): LocationFetcher.PermissionStatus
suspend fun requestEnableLocationSettings(): LocationFetcher.SettingsStatus

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LocationFetcher.create(this) {
    fastestInterval = 5000
    interval = 15000
    maxWaitTime = 100000
    priority = LocationRequest.PRIORITY_HIGH_ACCURACY
    smallestDisplacement = 50f
    providers = listOf(
        LocationRequest.Provider.GPS,
        LocationRequest.Provider.Network, 
        LocationRequest.Provider.Fused

psteiger

class MyActivity : AppCompatActivity() {

    private val locationFetcher: LocationFetcher by lazy {
        LocationFetcher.create(this)
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        with (locationFetcher) {
            location
                .onEach { /* Location received */ }

psteiger

sealed class Resource<out T> {
    
    data class Success<out T>(val data: T) : Resource<T>()
    data class Loading<out T>(val partialData: T? = null) : Resource<T>()
    data class Failure<out T>(val throwable: Throwable? = null) : Resource<T>()

}
 
val Resource<T>.extractData: T? get() = when (this) {
    is Success -> data

psteiger

package com.faztudo.common.livedata

import androidx.annotation.MainThread
import androidx.lifecycle.LiveData
import com.faztudo.App
import com.faztudo.INearbyUsersUseCases
import com.faztudo.common.helpers.logd
import com.faztudo.common.helpers.rootRef
import com.faztudo.common.helpers.sortedByDistance
import com.faztudo.common.helpers.usersRef

psteiger

open class FirebaseResourceLiveData(ref: DatabaseReference) : LiveData<Resource<DataSnapshot>> {
    init { 
        value = Resource.Loading() // setValue() of LiveData
    }
    
    private val listener = MyValueEventListener()

    override fun onActive() { // we have observers!
        value = Resource.Loading(value?.extractData)
        query.addValueEventListener(listener)

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sealed class Resource<out T> {
    
    data class Success<out T>(val data: T) : Resource<T>()
    data class Loading<out T>(val partialData: T? = null) : Resource<T>()
    data class Failure<out T>(val throwable: Throwable? = null) : Resource<T>()

    val extractData: T? get() = when (this) {
        is Success -> data
        is Loading -> partialData
        is Failure -> null

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inline fun <T> Resource<List<T>>.filterResource(predicate: (T) -> Boolean): Resource<List<T>> = try {
    when (this) {
        is Resource.Success<List<T>> -> Resource.Success<List<T>>(data.filter(predicate))
        is Resource.Loading<List<T>> -> Resource.Loading<List<T>>(partialData?.filter(predicate))
        is Resource.Failure<List<T>> -> Resource.Failure<List<T>>(throwable)
    }
} catch (e: Throwable) {
    Resource.Failure<List<T>>(e)
}