Merge "Receive location updates" into main

jdkoren · Gerrit Code Review · commit 2e38bfcb6b6a · 2022-03-31T22:58:18.000Z
diff --git a/ForegroundLocationUpdates/app/build.gradle b/ForegroundLocationUpdates/app/build.gradle
@@ -80,6 +80,7 @@ dependencies {
 
     // Play Services
     implementation 'com.google.android.gms:play-services-base:17.6.0'
+    implementation 'com.google.android.gms:play-services-location:18.0.0'
 
     // Hilt
     kapt "androidx.hilt:hilt-compiler:$hilt_compiler_version"
diff --git a/ForegroundLocationUpdates/app/src/main/java/com/google/android/gms/location/sample/foregroundlocation/ForegroundLocationApp.kt b/ForegroundLocationUpdates/app/src/main/java/com/google/android/gms/location/sample/foregroundlocation/ForegroundLocationApp.kt
@@ -18,6 +18,7 @@ package com.google.android.gms.location.sample.foregroundlocation
 
 import android.app.Application
 import com.google.android.gms.common.GoogleApiAvailability
+import com.google.android.gms.location.LocationServices
 import dagger.Module
 import dagger.Provides
 import dagger.hilt.InstallIn
@@ -35,4 +36,10 @@ object AppModule {
     @Provides
     @Singleton
     fun provideGoogleApiAvailability() = GoogleApiAvailability.getInstance()
+
+    @Provides
+    @Singleton
+    fun provideFusedLocationProviderClient(
+        application: Application
+    ) = LocationServices.getFusedLocationProviderClient(application)
 }
diff --git a/ForegroundLocationUpdates/app/src/main/java/com/google/android/gms/location/sample/foregroundlocation/MainActivity.kt b/ForegroundLocationUpdates/app/src/main/java/com/google/android/gms/location/sample/foregroundlocation/MainActivity.kt
@@ -17,7 +17,6 @@
 package com.google.android.gms.location.sample.foregroundlocation
 
 import android.os.Bundle
-import android.util.Log
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.viewModels
@@ -48,8 +47,7 @@ class MainActivity : ComponentActivity() {
 
         val locationPermissionState = LocationPermissionState(this) {
             if (it.hasPermission()) {
-                // TODO register for location updates
-                Log.d("ForegroundLocation", "TODO register for location updates")
+                viewModel.toggleLocationUpdates()
             }
         }
 
@@ -80,14 +78,19 @@ fun MainScreen(
     locationPermissionState: LocationPermissionState
 ) {
     val uiState by viewModel.playServicesAvailableState.collectAsState()
+    val isLocationOn by viewModel.isReceivingLocationUpdates.collectAsState()
+    val lastLocation by viewModel.lastLocation.collectAsState()
+
     when (uiState) {
         Initializing -> InitializingScreen()
         PlayServicesUnavailable -> ServiceUnavailableScreen()
         PlayServicesAvailable -> {
             LocationUpdatesScreen(
                 showDegradedExperience = locationPermissionState.showDegradedExperience,
                 needsPermissionRationale = locationPermissionState.shouldShowRationale(),
-                onButtonClick = locationPermissionState::requestPermissions
+                onButtonClick = locationPermissionState::requestPermissions,
+                isLocationOn = isLocationOn,
+                location = lastLocation,
             )
         }
     }
diff --git a/ForegroundLocationUpdates/app/src/main/java/com/google/android/gms/location/sample/foregroundlocation/MainViewModel.kt b/ForegroundLocationUpdates/app/src/main/java/com/google/android/gms/location/sample/foregroundlocation/MainViewModel.kt
@@ -21,6 +21,7 @@ import androidx.lifecycle.viewModelScope
 import com.google.android.gms.location.sample.foregroundlocation.PlayServicesAvailableState.Initializing
 import com.google.android.gms.location.sample.foregroundlocation.PlayServicesAvailableState.PlayServicesAvailable
 import com.google.android.gms.location.sample.foregroundlocation.PlayServicesAvailableState.PlayServicesUnavailable
+import com.google.android.gms.location.sample.foregroundlocation.data.LocationRepository
 import com.google.android.gms.location.sample.foregroundlocation.data.PlayServicesAvailabilityChecker
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.SharingStarted
@@ -30,7 +31,8 @@ import javax.inject.Inject
 
 @HiltViewModel
 class MainViewModel @Inject constructor(
-    playServicesAvailabilityChecker: PlayServicesAvailabilityChecker
+    playServicesAvailabilityChecker: PlayServicesAvailabilityChecker,
+    private val locationRepository: LocationRepository
 ) : ViewModel() {
 
     val playServicesAvailableState = flow {
@@ -43,6 +45,16 @@ class MainViewModel @Inject constructor(
         )
     }.stateIn(viewModelScope, SharingStarted.Eagerly, Initializing)
 
+    val isReceivingLocationUpdates = locationRepository.isReceivingLocationUpdates
+    val lastLocation = locationRepository.lastLocation
+
+    fun toggleLocationUpdates() {
+        if (isReceivingLocationUpdates.value) {
+            locationRepository.stopLocationUpdates()
+        } else {
+            locationRepository.startLocationUpdates()
+        }
+    }
 }
 
 enum class PlayServicesAvailableState {
diff --git a/ForegroundLocationUpdates/app/src/main/java/com/google/android/gms/location/sample/foregroundlocation/data/LocationRepository.kt b/ForegroundLocationUpdates/app/src/main/java/com/google/android/gms/location/sample/foregroundlocation/data/LocationRepository.kt
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2021 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.gms.location.sample.foregroundlocation.data
+
+import android.annotation.SuppressLint
+import android.location.Location
+import android.os.Looper
+import com.google.android.gms.location.FusedLocationProviderClient
+import com.google.android.gms.location.LocationCallback
+import com.google.android.gms.location.LocationRequest
+import com.google.android.gms.location.LocationResult
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import javax.inject.Inject
+
+class LocationRepository @Inject constructor(
+    private val fusedLocationProviderClient: FusedLocationProviderClient
+) {
+    private val callback = Callback()
+
+    private val _isReceivingUpdates = MutableStateFlow(false)
+    val isReceivingLocationUpdates = _isReceivingUpdates.asStateFlow()
+
+    private val _lastLocation = MutableStateFlow<Location?>(null)
+    val lastLocation = _lastLocation.asStateFlow()
+
+    @SuppressLint("MissingPermission") // Only called when holding location permission.
+    fun startLocationUpdates() {
+        val request = LocationRequest.create().apply {
+            priority = LocationRequest.PRIORITY_HIGH_ACCURACY
+            interval = 10_000 // 10 seconds
+        }
+        // Note: For this sample it's fine to use the main looper, so our callback will run on the
+        // main thread. If your callback will perform any intensive operations (writing to disk,
+        // making a network request, etc.), either change to a background thread from the callback,
+        // or create a HandlerThread and pass its Looper here instead.
+        // See https://developer.android.com/reference/android/os/HandlerThread.
+        fusedLocationProviderClient.requestLocationUpdates(
+            request,
+            callback,
+            Looper.getMainLooper()
+        )
+        _isReceivingUpdates.value = true
+    }
+
+    fun stopLocationUpdates() {
+        fusedLocationProviderClient.removeLocationUpdates(callback)
+        _isReceivingUpdates.value = false
+        _lastLocation.value = null
+    }
+
+    inner class Callback : LocationCallback() {
+        override fun onLocationResult(result: LocationResult) {
+            _lastLocation.value = result.lastLocation
+        }
+    }
+}
diff --git a/ForegroundLocationUpdates/app/src/main/java/com/google/android/gms/location/sample/foregroundlocation/ui/LocationUpdatesScreen.kt b/ForegroundLocationUpdates/app/src/main/java/com/google/android/gms/location/sample/foregroundlocation/ui/LocationUpdatesScreen.kt
@@ -16,6 +16,7 @@
 
 package com.google.android.gms.location.sample.foregroundlocation.ui
 
+import android.location.Location
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.fillMaxSize
@@ -42,7 +43,9 @@ import com.google.android.gms.location.sample.foregroundlocation.ui.theme.Foregr
 fun LocationUpdatesScreen(
     showDegradedExperience: Boolean,
     needsPermissionRationale: Boolean,
-    onButtonClick: () -> Unit
+    onButtonClick: () -> Unit,
+    isLocationOn: Boolean,
+    location: Location?
 ) {
     var showRationaleDialog by remember { mutableStateOf(false) }
     if (showRationaleDialog) {
@@ -63,26 +66,35 @@ fun LocationUpdatesScreen(
         }
     }
 
+    val message = when {
+        isLocationOn -> if (location != null) {
+            stringResource(
+                id = R.string.location_lat_lng,
+                location.latitude,
+                location.longitude
+            )
+        } else {
+            stringResource(id = R.string.waiting_for_location)
+        }
+        showDegradedExperience -> stringResource(id = R.string.please_allow_permission)
+        else -> stringResource(id = R.string.not_started)
+    }
+    val labelResId = if (isLocationOn) R.string.stop else R.string.start
+
     Column(
         modifier = Modifier
             .fillMaxSize()
             .padding(16.dp),
         horizontalAlignment = Alignment.CenterHorizontally,
         verticalArrangement = Arrangement.SpaceEvenly
     ) {
-        val message = if (showDegradedExperience) {
-            stringResource(id = R.string.please_allow_permission)
-        } else {
-            stringResource(id = R.string.not_started)
-        }
-
         Text(
             text = message,
             style = MaterialTheme.typography.h6,
             textAlign = TextAlign.Center
         )
         Button(onClick = { onClick() }) {
-            Text(text = stringResource(id = R.string.start))
+            Text(text = stringResource(id = labelResId))
         }
     }
 }
@@ -120,7 +132,9 @@ fun LocationUpdatesScreenPreview() {
         LocationUpdatesScreen(
             showDegradedExperience = false,
             needsPermissionRationale = false,
-            onButtonClick = {}
+            onButtonClick = {},
+            isLocationOn = true,
+            location = null,
         )
     }
 }
diff --git a/ForegroundLocationUpdates/app/src/main/res/values/strings.xml b/ForegroundLocationUpdates/app/src/main/res/values/strings.xml
@@ -22,7 +22,11 @@
     <string name="start">Start</string>
     <string name="stop">Stop</string>
     <string name="not_started">Tap Start to receive location updates</string>
+
     <string name="please_allow_permission">Please allow permission to access location</string>
     <string name="permission_rationale_dialog_title">Permission needed</string>
     <string name="permission_rationale_dialog_message">This app requires permission to access your location. Please accept.</string>
+
+    <string name="waiting_for_location">Waiting for location…</string>
+    <string name="location_lat_lng">Lat: %1$f\nLng: %2$f</string>
 </resources>
