[Capture location] Prompt for location permissions when capture locat…

…ion task is opened (#2818)

* dialog ui added

* show dialog for the first time when enter

* added permission check

* string and view fix

ground/src/main/java/com/google/android/ground/system/PermissionsManager.kt

@@ -60,7 +60,7 @@ constructor(
       false
     }
 
-  /** Returns `true` iff the app has been granted the specified permission. */
+  /** Returns `true` if the app has been granted the specified permission. */
   fun isGranted(permission: String): Boolean =
     checkSelfPermission(context, permission) == PackageManager.PERMISSION_GRANTED
 

ground/src/main/java/com/google/android/ground/ui/datacollection/tasks/location/CaptureLocationTaskMapFragment.kt

@@ -19,10 +19,15 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.platform.ComposeView
 import androidx.lifecycle.lifecycleScope
 import com.google.android.ground.ui.common.AbstractMapFragmentWithControls
 import com.google.android.ground.ui.common.BaseMapViewModel
 import com.google.android.ground.ui.map.MapFragment
+import com.google.android.ground.ui.theme.AppTheme
 import dagger.hilt.android.AndroidEntryPoint
 import javax.inject.Inject
 import kotlinx.coroutines.launch
@@ -57,9 +62,46 @@ class CaptureLocationTaskMapFragment @Inject constructor() : AbstractMapFragment
     return root
   }
 
+  override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+    super.onViewCreated(view, savedInstanceState)
+    lifecycleScope.launch {
+      viewModel.enableLocationLockFlow.collect {
+        if (it == LocationLockEnabledState.NEEDS_ENABLE) {
+          showLocationPermissionDialog()
+        }
+      }
+    }
+  }
+
   override fun onMapReady(map: MapFragment) {
     super.onMapReady(map)
-    binding.locationLockBtn.isClickable = false
     viewLifecycleOwner.lifecycleScope.launch { viewModel.onMapReady(mapViewModel) }
   }
+
+  @Suppress("LabeledExpression")
+  private fun showLocationPermissionDialog() {
+    val dialogComposeView =
+      ComposeView(requireContext()).apply {
+        setContent {
+          val openAlertDialog = remember { mutableStateOf(true) }
+          when {
+            openAlertDialog.value -> {
+              AppTheme {
+                LocationPermissionDialog(
+                  onCancel = {
+                    binding.locationLockBtn.isClickable = false
+                    openAlertDialog.value = false
+                  },
+                  onDismiss = { openAlertDialog.value = false },
+                )
+              }
+            }
+          }
+
+          DisposableEffect(Unit) { onDispose { (parent as? ViewGroup)?.removeView(this@apply) } }
+        }
+      }
+
+    (view as ViewGroup).addView(dialogComposeView)
+  }
 }

ground/src/main/java/com/google/android/ground/ui/datacollection/tasks/location/CaptureLocationTaskViewModel.kt

@@ -23,10 +23,11 @@ import com.google.android.ground.ui.common.BaseMapViewModel
 import com.google.android.ground.ui.datacollection.tasks.AbstractTaskViewModel
 import javax.inject.Inject
 import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.launch
 
 /** Location lock states relevant for attempting to enable it or not. */
-private enum class LocationLockEnabledState {
+enum class LocationLockEnabledState {
   /** The default, unknown state. */
   UNKNOWN,
 
@@ -44,23 +45,24 @@ class CaptureLocationTaskViewModel @Inject constructor() : AbstractTaskViewModel
 
   private val lastLocation = MutableStateFlow<CaptureLocationTaskData?>(null)
   /** Allows control for triggering the location lock programmatically. */
-  private val enableLocationLockFlow = MutableStateFlow(LocationLockEnabledState.UNKNOWN)
+  private val _enableLocationLockFlow = MutableStateFlow(LocationLockEnabledState.UNKNOWN)
+  val enableLocationLockFlow = _enableLocationLockFlow.asStateFlow()
 
   suspend fun updateLocation(location: Location) {
     lastLocation.emit(location.toCaptureLocationResult())
   }
 
   fun updateResponse() {
     if (lastLocation.value == null) {
-      viewModelScope.launch { enableLocationLockFlow.emit(LocationLockEnabledState.ENABLE) }
+      viewModelScope.launch { _enableLocationLockFlow.emit(LocationLockEnabledState.ENABLE) }
     } else {
       setValue(lastLocation.value)
     }
   }
 
   fun enableLocationLock() {
-    if (enableLocationLockFlow.value == LocationLockEnabledState.NEEDS_ENABLE) {
-      viewModelScope.launch { enableLocationLockFlow.emit(LocationLockEnabledState.ENABLE) }
+    if (_enableLocationLockFlow.value == LocationLockEnabledState.NEEDS_ENABLE) {
+      viewModelScope.launch { _enableLocationLockFlow.emit(LocationLockEnabledState.ENABLE) }
     }
   }
 
@@ -74,12 +76,12 @@ class CaptureLocationTaskViewModel @Inject constructor() : AbstractTaskViewModel
         // Otherwise, wait to enable location lock until later.
         LocationLockEnabledState.NEEDS_ENABLE
       }
-    enableLocationLockFlow.value = locationLockEnabledState
-    enableLocationLockFlow.collect {
+    _enableLocationLockFlow.value = locationLockEnabledState
+    _enableLocationLockFlow.collect {
       if (it == LocationLockEnabledState.ENABLE) {
         // No-op if permission is already granted and location updates are enabled.
         mapViewModel.enableLocationLockAndGetUpdates()
-        enableLocationLockFlow.value = LocationLockEnabledState.ALREADY_ENABLED
+        _enableLocationLockFlow.value = LocationLockEnabledState.ALREADY_ENABLED
       }
     }
   }

ground/src/main/java/com/google/android/ground/ui/datacollection/tasks/location/LocationPermissionDialog.kt

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * 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.ground.ui.datacollection.tasks.location
+
+import android.content.Intent
+import android.net.Uri
+import android.provider.Settings
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.tooling.preview.Preview
+import com.google.android.ground.R
+import com.google.android.ground.ui.theme.AppTheme
+
+@Composable
+fun LocationPermissionDialog(onDismiss: () -> Unit, onCancel: () -> Unit) {
+  val context = LocalContext.current
+  AlertDialog(
+    containerColor = MaterialTheme.colorScheme.surface,
+    onDismissRequest = { onDismiss() },
+    title = {
+      Text(
+        stringResource(R.string.allow_location_title),
+        color = MaterialTheme.colorScheme.onSurface,
+      )
+    },
+    text = {
+      Text(
+        stringResource(R.string.allow_location_description),
+        color = MaterialTheme.colorScheme.onSurfaceVariant,
+      )
+    },
+    dismissButton = {
+      TextButton(onClick = { onCancel() }) { Text(text = stringResource(R.string.cancel)) }
+    },
+    confirmButton = {
+      TextButton(
+        onClick = {
+          // Open the app settings
+          val intent = Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS)
+          val uri = Uri.fromParts("package", context.packageName, null)
+          intent.data = uri
+          context.startActivity(intent)
+        }
+      ) {
+        Text(text = stringResource(R.string.allow_location_confirmation))
+      }
+    },
+  )
+}
+
+@Composable
+@Preview
+fun PreviewUserDetailsDialog() {
+  AppTheme { LocationPermissionDialog({}, {}) }
+}

ground/src/main/res/values/strings.xml

@@ -188,4 +188,8 @@
   <string name="data_submitted_image">Data submitted image</string>
   <string name="data_collection_complete">Data collection complete!</string>
   <string name="data_collection_complete_details">Your data has been saved and will be automatically synced when you’re online.</string>
+
+  <string name="allow_location_confirmation">Allow location</string>
+  <string name="allow_location_title">Allow location sharing</string>
+  <string name="allow_location_description">If you don&#8217;t allow Ground to access this device&#8217;s location, you won&#8217;t be able to continue collecting data for this site.</string>
 </resources>