feat: request background location permission (#86)

ios/Runner/Info.plist

@@ -50,7 +50,7 @@
 	<key>NSLocationAlwaysAndWhenInUseUsageDescription</key>
 	<string>Application needs Your location to show nearby aircraft.</string>
 	<key>NSLocationAlwaysUsageDescription</key>
-	<string>Application needs Your location to show nearby aircraft.</string>
+	<string>Application needs background location for Drone Radar feature.</string>
 	<key>NSLocationWhenInUseUsageDescription</key>
 	<string>Application needs Your location to show nearby aircraft.</string>
 	<key>UIApplicationSupportsIndirectInputEvents</key>

lib/bloc/standards_cubit.dart

@@ -8,19 +8,25 @@ import 'package:logging/logging.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
 class StandardsState {
-  bool androidSystem = false;
-  bool btLegacy = false; // bt4
-  bool btExtended = false; // bt4
-  bool wifiBeacon = false;
-  bool wifiNaN = false; // aware on android
-  bool btExtendedClaimed = false; // can be claimed but still not work
+  final bool androidSystem;
+  final bool btLegacy; // bt4
+  final bool btExtended; // bt5
+  final bool wifiBeacon;
+  final bool wifiNaN; // aware on android
+  final bool btExtendedClaimed; // can be claimed but still not work
   // if adv len is < 1000, we stronly suspect Bt long range scanning wont work
-  int maxAdvDataLen = 0;
+  final int maxAdvDataLen;
   // permissions
-  bool btEnabled = false;
-  bool locationEnabled = false;
-  bool notificationsEnabled = false;
-  bool internetAvailable = false;
+  final bool btEnabled;
+  final bool locationEnabled;
+  final bool backgroundLocationEnabled;
+  // true if user was asked about background location and cancelled request
+  final bool backgroundLocationDenied;
+  final bool notificationsEnabled;
+  final bool internetAvailable;
+
+  static const logPlatformStandardsKey = 'logPlatformStandards';
+  static const backgroundLocationDeniedKey = 'backgroundLocationDenied';
 
   StandardsState({
     required this.androidSystem,
@@ -32,6 +38,8 @@ class StandardsState {
     required this.maxAdvDataLen,
     required this.btEnabled,
     required this.locationEnabled,
+    required this.backgroundLocationEnabled,
+    required this.backgroundLocationDenied,
     required this.notificationsEnabled,
     required this.internetAvailable,
   });
@@ -46,6 +54,8 @@ class StandardsState {
     int? maxAdvDataLen,
     bool? btEnabled,
     bool? locationEnabled,
+    bool? backgroundLocationEnabled,
+    bool? backgroundLocationDenied,
     bool? notificationsEnabled,
     bool? internetAvailable,
   }) =>
@@ -59,6 +69,10 @@ class StandardsState {
         maxAdvDataLen: maxAdvDataLen ?? this.maxAdvDataLen,
         btEnabled: btEnabled ?? this.btEnabled,
         locationEnabled: locationEnabled ?? this.locationEnabled,
+        backgroundLocationDenied:
+            backgroundLocationDenied ?? this.backgroundLocationDenied,
+        backgroundLocationEnabled:
+            backgroundLocationEnabled ?? this.backgroundLocationEnabled,
         notificationsEnabled: notificationsEnabled ?? this.notificationsEnabled,
         internetAvailable: internetAvailable ?? this.internetAvailable,
       );
@@ -79,6 +93,8 @@ class StandardsCubit extends Cubit<StandardsState> {
             internetAvailable: false,
             notificationsEnabled: false,
             locationEnabled: false,
+            backgroundLocationEnabled: false,
+            backgroundLocationDenied: false,
           ),
         );
 
@@ -128,7 +144,14 @@ class StandardsCubit extends Cubit<StandardsState> {
     );
 
     final preferences = await SharedPreferences.getInstance();
-    final logPlatformStatus = preferences.getBool('logPlatformStandards');
+
+    final backgroundLocationDenied =
+        preferences.getBool(StandardsState.backgroundLocationDeniedKey) ??
+            false;
+    emit(state.copyWith(backgroundLocationDenied: backgroundLocationDenied));
+
+    final logPlatformStatus =
+        preferences.getBool(StandardsState.logPlatformStandardsKey);
     // skip if info was already logged
     if (logPlatformStatus != null && !logPlatformStatus) {
       return;
@@ -159,22 +182,28 @@ class StandardsCubit extends Cubit<StandardsState> {
     Logger.root.info('maxAdvDataLen $maxAdvDataLen');
 
     // set that platforms standards were already logged
-    await preferences.setBool('logPlatformStandards', true);
+    await preferences.setBool(StandardsState.logPlatformStandardsKey, true);
   }
 
-  Future<void> setLocationEnabled({required bool enabled}) async {
-    emit(state.copyWith(locationEnabled: enabled));
-  }
+  void setLocationEnabled({required bool enabled}) =>
+      emit(state.copyWith(locationEnabled: enabled));
 
-  Future<void> setBluetoothEnabled({required bool enabled}) async {
-    emit(state.copyWith(btEnabled: enabled));
-  }
+  void setBackgroundLocationEnabled({required bool enabled}) async =>
+      emit(state.copyWith(backgroundLocationEnabled: enabled));
 
-  Future<void> setNotificationsEnabled({required bool enabled}) async {
-    emit(state.copyWith(notificationsEnabled: enabled));
+  Future<void> setBackgroundLocationDenied() async {
+    final preferences = await SharedPreferences.getInstance();
+    preferences.setBool(StandardsState.backgroundLocationDeniedKey, true);
+    emit(state.copyWith(
+        backgroundLocationEnabled: false, backgroundLocationDenied: true));
   }
 
-  Future<void> setInternetAvailable({required bool available}) async {
-    emit(state.copyWith(internetAvailable: available));
-  }
+  void setBluetoothEnabled({required bool enabled}) =>
+      emit(state.copyWith(btEnabled: enabled));
+
+  void setNotificationsEnabled({required bool enabled}) =>
+      emit(state.copyWith(notificationsEnabled: enabled));
+
+  void setInternetAvailable({required bool available}) =>
+      emit(state.copyWith(internetAvailable: available));
 }

lib/widgets/app/dialogs.dart

@@ -1,3 +1,5 @@
+import 'dart:io';
+
 import 'package:another_flushbar/flushbar.dart';
 import 'package:app_settings/app_settings.dart';
 import 'package:flutter/material.dart';
@@ -48,25 +50,7 @@ Future<bool> showLocationPermissionDialog({
   required bool showWhileUsingPermissionExplanation,
 }) async {
   // set up the buttons
-  final Widget cancelButton = TextButton(
-    child: const Text('Cancel'),
-    onPressed: () {
-      Navigator.pop(context, false);
-    },
-  );
-  final Widget appSettingsButton = TextButton(
-    child: const Text('App settings'),
-    onPressed: () {
-      Navigator.pop(context, false);
-      AppSettings.openAppSettings();
-    },
-  );
-  final Widget continueButton = TextButton(
-    child: const Text('Continue'),
-    onPressed: () {
-      Navigator.pop(context, true);
-    },
-  );
+  final actions = _getPermissionDialogActions(context);
   // set up the AlertDialog
   final alert = AlertDialog(
     title: const Text('Location permission required'),
@@ -82,7 +66,8 @@ Future<bool> showLocationPermissionDialog({
               style: TextStyle(fontWeight: FontWeight.w700),
             ),
             const TextSpan(
-              text: 'option to enable scans in the background.\n\n',
+              text:
+                  'option to enable scans while the app is in foreground.\n\n',
             ),
           ],
           const TextSpan(
@@ -96,10 +81,49 @@ Future<bool> showLocationPermissionDialog({
         ],
       ),
     ),
+    actions: actions.values.toList(),
+  );
+  // show the dialog
+  final result = await showDialog<bool>(
+    context: context,
+    builder: (context) {
+      return alert;
+    },
+  );
+  return result ?? false;
+}
+
+Future<bool> showBackgroundPermissionDialog({
+  required BuildContext context,
+}) async {
+  // set up the buttons
+  final actions = _getPermissionDialogActions(context);
+  final isAndroid = Platform.isAndroid;
+  // set up the AlertDialog
+  final alert = AlertDialog(
+    title: const Text('Background location permission'),
+    content: const Text.rich(
+      TextSpan(
+        text: 'Drone Scanner requires background location permission to scan '
+            'for nearby aircraft while in the background.\n\n',
+        children: [
+          TextSpan(
+              text: 'If you wish to use the Drone Radar feature or gather data '
+                  'while the app is minimized, please select\nthe '),
+          TextSpan(
+            text: '"Allow all the time"\n',
+            style: TextStyle(fontWeight: FontWeight.w700),
+          ),
+          TextSpan(
+            text: 'option in application settings.\n\n',
+          ),
+        ],
+      ),
+    ),
     actions: [
-      cancelButton,
-      appSettingsButton,
-      continueButton,
+      actions['cancel']!,
+      if (isAndroid) actions['continue']!,
+      if (!isAndroid) actions['appSettings']!,
     ],
   );
   // show the dialog
@@ -112,6 +136,30 @@ Future<bool> showLocationPermissionDialog({
   return result ?? false;
 }
 
+Map<String, Widget> _getPermissionDialogActions(BuildContext context) {
+  return {
+    'cancel': TextButton(
+      child: const Text('Cancel'),
+      onPressed: () {
+        Navigator.pop(context, false);
+      },
+    ),
+    'appSettings': TextButton(
+      child: const Text('App settings'),
+      onPressed: () {
+        Navigator.pop(context, true);
+        AppSettings.openAppSettings();
+      },
+    ),
+    'continue': TextButton(
+      child: const Text('Continue'),
+      onPressed: () {
+        Navigator.pop(context, true);
+      },
+    ),
+  };
+}
+
 void showSnackBar(
   BuildContext context,
   String snackBarText, {