LocationSource.kt
| 1 | package org.opentracker |
| 2 | |
| 3 | import android.annotation.SuppressLint |
| 4 | import android.location.Location |
| 5 | import android.location.LocationListener |
| 6 | import android.location.LocationManager |
| 7 | import android.location.LocationRequest |
| 8 | import java.util.concurrent.Executor |
| 9 | |
| 10 | /** |
| 11 | * Plain LocationManager, so the app works without Google Play Services. |
| 12 | * It passes on every fix. [SamplingPolicy] decides what to keep. |
| 13 | */ |
| 14 | class LocationSource( |
| 15 | private val lm: LocationManager, |
| 16 | private val executor: Executor, |
| 17 | private val onFixes: (List<Location>) -> Unit, |
| 18 | ) { |
| 19 | private val listener = object : LocationListener { |
| 20 | override fun onLocationChanged(location: Location) = onFixes(listOf(location)) |
| 21 | |
| 22 | override fun onLocationChanged(locations: MutableList<Location>) = onFixes(locations) |
| 23 | |
| 24 | override fun onProviderEnabled(provider: String) = Unit |
| 25 | |
| 26 | override fun onProviderDisabled(provider: String) = Unit |
| 27 | } |
| 28 | private var current: Request? = null |
| 29 | |
| 30 | /** Some GNSS chips, the emulator's among them, accept a batching request and then deliver nothing. */ |
| 31 | var batching = true |
| 32 | set(value) { |
| 33 | field = value |
| 34 | current?.let { |
| 35 | current = null |
| 36 | apply(it) |
| 37 | } |
| 38 | } |
| 39 | |
| 40 | /** LocationManager cannot change a running request, so a new one replaces it. Returns whether it changed. */ |
| 41 | @SuppressLint("MissingPermission") |
| 42 | fun apply(req: Request): Boolean { |
| 43 | if (req == current) return false |
| 44 | stop() |
| 45 | current = req |
| 46 | val quality = if (req.gnss) LocationRequest.QUALITY_HIGH_ACCURACY else LocationRequest.QUALITY_LOW_POWER |
| 47 | // No minimum distance: the policy needs fixes from a still phone to notice that it stopped. |
| 48 | val lr = LocationRequest.Builder(req.intervalMs) |
| 49 | .setMaxUpdateDelayMillis(if (batching) req.maxDelayMs else 0) |
| 50 | .setQuality(quality) |
| 51 | .build() |
| 52 | val providers = lm.allProviders |
| 53 | val wanted = buildList { |
| 54 | if (req.gnss) add(LocationManager.GPS_PROVIDER) |
| 55 | if (LocationManager.NETWORK_PROVIDER in providers) add(LocationManager.NETWORK_PROVIDER) |
| 56 | // Phones without Google services often have no network provider. GNSS then has to cover it. |
| 57 | else if (!req.gnss) add(LocationManager.GPS_PROVIDER) |
| 58 | } |
| 59 | for (p in wanted.filter { it in providers }) lm.requestLocationUpdates(p, lr, executor, listener) |
| 60 | return true |
| 61 | } |
| 62 | |
| 63 | fun stop() { |
| 64 | lm.removeUpdates(listener) |
| 65 | current = null |
| 66 | } |
| 67 | } |
| 68 |