update example app to use new api

permission_handler/example/lib/main.dart

@@ -17,33 +17,31 @@ class MyApp extends StatelessWidget {
           actions: <Widget>[
             IconButton(
               icon: const Icon(Icons.settings),
-              onPressed: () {
-                PermissionHandler().openAppSettings().then((bool hasOpened) =>
-                    debugPrint('App Settings opened: ' + hasOpened.toString()));
+              onPressed: () async {
+                var hasOpened = openAppSettings();
+                debugPrint('App Settings opened: ' + hasOpened.toString());
               },
             )
           ],
         ),
         body: Center(
           child: ListView(
-              children: PermissionGroup.values
-                  .where((PermissionGroup permission) {
+              children: Permission.values
+                  .where((Permission permission) {
                     if (Platform.isIOS) {
-                      return permission != PermissionGroup.unknown &&
-                          permission != PermissionGroup.sms &&
-                          permission != PermissionGroup.storage &&
-                          permission !=
-                              PermissionGroup.ignoreBatteryOptimizations &&
-                          permission != PermissionGroup.accessMediaLocation;
+                      return permission != Permission.unknown &&
+                          permission != Permission.sms &&
+                          permission != Permission.storage &&
+                          permission != Permission.ignoreBatteryOptimizations &&
+                          permission != Permission.accessMediaLocation;
                     } else {
-                      return permission != PermissionGroup.unknown &&
-                          permission != PermissionGroup.mediaLibrary &&
-                          permission != PermissionGroup.photos &&
-                          permission != PermissionGroup.reminders;
+                      return permission != Permission.unknown &&
+                          permission != Permission.mediaLibrary &&
+                          permission != Permission.photos &&
+                          permission != Permission.reminders;
                     }
                   })
-                  .map((PermissionGroup permission) =>
-                      PermissionWidget(permission))
+                  .map((permission) => PermissionWidget(permission))
                   .toList()),
         ),
       ),
@@ -54,19 +52,19 @@ class MyApp extends StatelessWidget {
 /// Permission widget which displays a permission and allows users to request
 /// the permissions.
 class PermissionWidget extends StatefulWidget {
-  /// Constructs a [PermissionWidget] for the supplied [PermissionGroup].
-  const PermissionWidget(this._permissionGroup);
+  /// Constructs a [PermissionWidget] for the supplied [Permission].
+  const PermissionWidget(this._permission);
 
-  final PermissionGroup _permissionGroup;
+  final Permission _permission;
 
   @override
-  _PermissionState createState() => _PermissionState(_permissionGroup);
+  _PermissionState createState() => _PermissionState(_permission);
 }
 
 class _PermissionState extends State<PermissionWidget> {
-  _PermissionState(this._permissionGroup);
+  _PermissionState(this._permission);
 
-  final PermissionGroup _permissionGroup;
+  final Permission _permission;
   PermissionStatus _permissionStatus = PermissionStatus.unknown;
 
   @override
@@ -76,15 +74,9 @@ class _PermissionState extends State<PermissionWidget> {
     _listenForPermissionStatus();
   }
 
-  void _listenForPermissionStatus() {
-    final Future<PermissionStatus> statusFuture =
-        PermissionHandler().checkPermissionStatus(_permissionGroup);
-
-    statusFuture.then((PermissionStatus status) {
-      setState(() {
-        _permissionStatus = status;
-      });
-    });
+  void _listenForPermissionStatus() async {
+    final status = await _permission.status;
+    setState(() => _permissionStatus = status);
   }
 
   Color getPermissionColor() {
@@ -101,7 +93,7 @@ class _PermissionState extends State<PermissionWidget> {
   @override
   Widget build(BuildContext context) {
     return ListTile(
-      title: Text(_permissionGroup.toString()),
+      title: Text(_permission.toString()),
       subtitle: Text(
         _permissionStatus.toString(),
         style: TextStyle(color: getPermissionColor()),
@@ -109,33 +101,26 @@ class _PermissionState extends State<PermissionWidget> {
       trailing: IconButton(
           icon: const Icon(Icons.info),
           onPressed: () {
-            checkServiceStatus(context, _permissionGroup);
+            checkServiceStatus(context, _permission);
           }),
       onTap: () {
-        requestPermission(_permissionGroup);
+        requestPermission(_permission);
       },
     );
   }
 
-  void checkServiceStatus(BuildContext context, PermissionGroup permission) {
-    PermissionHandler()
-        .checkServiceStatus(permission)
-        .then((ServiceStatus serviceStatus) {
-      final SnackBar snackBar =
-          SnackBar(content: Text(serviceStatus.toString()));
-
-      Scaffold.of(context).showSnackBar(snackBar);
-    });
+  void checkServiceStatus(BuildContext context, Permission permission) async {
+    Scaffold.of(context).showSnackBar(SnackBar(
+      content: Text((await permission.status).toString()),
+    ));
   }
 
-  Future<void> requestPermission(PermissionGroup permission) async {
-    final List<PermissionGroup> permissions = <PermissionGroup>[permission];
-    final Map<PermissionGroup, PermissionStatus> permissionRequestResult =
-        await PermissionHandler().requestPermissions(permissions);
+  Future<void> requestPermission(Permission permission) async {
+    final status = await permission.request();
 
     setState(() {
-      print(permissionRequestResult);
-      _permissionStatus = permissionRequestResult[permission];
+      print(status);
+      _permissionStatus = status;
       print(_permissionStatus);
     });
   }