Can update following status of a group

lib/helpers/groups_helper.dart

@@ -148,6 +148,14 @@ class GroupsHelper {
         "accept": accept ? "true" : "false",
       });
 
+  /// Update group following status
+  Future<bool> setFollowing(int groupID, bool follow) async =>
+      (await (APIRequest(uri: "groups/set_following", needLogin: true)
+                ..addInt("groupID", groupID)
+                ..addBool("follow", follow))
+              .exec())
+          .isOK;
+
   /// Get advanced information about the user
   Future<GetAdvancedInfoResult> getAdvancedInfo(int groupID) async {
     // Get advanced information about the user

lib/models/group.dart

@@ -29,7 +29,7 @@ class Group {
   final GroupRegistrationLevel registrationLevel;
   final GroupPostCreationLevel postCreationLevel;
   final String virtualDirectory;
-  final bool following;
+  bool following;
 
   Group({
     @required this.id,
@@ -54,7 +54,7 @@ class Group {
 
   get displayName => this.name;
 
-  bool get getIsAtLeastMember =>
+  bool get isAtLeastMember =>
       membershipLevel == GroupMembershipLevel.ADMINISTRATOR ||
       membershipLevel == GroupMembershipLevel.MODERATOR ||
       membershipLevel == GroupMembershipLevel.MEMBER;

lib/ui/screens/authorized_group_page_screen.dart

@@ -1,4 +1,5 @@
 import 'package:comunic/models/advanced_group_info.dart';
+import 'package:comunic/ui/widgets/group_following_widget.dart';
 import 'package:comunic/ui/widgets/group_icon_widget.dart';
 import 'package:comunic/ui/widgets/group_membership_widget.dart';
 import 'package:flutter/material.dart';
@@ -50,9 +51,18 @@ class _AuthorizedGroupPageScreenState extends State<AuthorizedGroupPageScreen> {
             style: TextStyle(fontSize: 20),
           ),
           Spacer(),
-          GroupMembershipWidget(
-            group: _group,
-            onUpdated: () => widget.needRefresh(),
+          Column(
+            children: <Widget>[
+              GroupMembershipWidget(
+                group: _group,
+                onUpdated: () => widget.needRefresh(),
+              ),
+              Container(height: 10,),
+              GroupFollowingWidget(
+                group: _group,
+                onUpdated: () => widget.needRefresh(),
+              ),
+            ],
           )
         ],
       ),

lib/ui/screens/group_access_denied_screen.dart

@@ -95,7 +95,7 @@ class _GroupAccessDeniedScreenState extends SafeState<GroupAccessDeniedScreen> {
       // Get information about a single group
       final group = await GroupsHelper().getSingle(widget.groupID, force: true);
 
-      if (group.getIsAtLeastMember) widget.onMembershipAcquired();
+      if (group.isAtLeastMember) widget.onMembershipAcquired();
 
       setState(() => _group = group);
     } catch (e) {

lib/ui/widgets/group_following_widget.dart

@@ -0,0 +1,55 @@
+import 'package:comunic/helpers/groups_helper.dart';
+import 'package:comunic/models/group.dart';
+import 'package:comunic/ui/widgets/safe_state.dart';
+import 'package:comunic/utils/intl_utils.dart';
+import 'package:comunic/utils/ui_utils.dart';
+import 'package:flutter/material.dart';
+
+/// Group following status widget
+///
+/// @author Pierre Hubert
+
+class GroupFollowingWidget extends StatefulWidget {
+  final Group group;
+  final Function() onUpdated;
+
+  const GroupFollowingWidget(
+      {Key key, @required this.group, @required this.onUpdated})
+      : assert(group != null),
+        assert(onUpdated != null),
+        super(key: key);
+
+  @override
+  _GroupFollowingWidgetState createState() => _GroupFollowingWidgetState();
+}
+
+class _GroupFollowingWidgetState extends SafeState<GroupFollowingWidget> {
+  Group get _group => widget.group;
+
+  @override
+  Widget build(BuildContext context) {
+    if (!_group.isAtLeastMember) return Container();
+
+    return InkWell(
+      child: Text(
+        _group.following ? tr("Following") : tr("Follow"),
+        style: TextStyle(color: Colors.blue),
+      ),
+      onTap: () => _toggleFollowing(),
+    );
+  }
+
+  /// Toggle following status
+  void _toggleFollowing() async {
+    if (!await GroupsHelper().setFollowing(_group.id, !_group.following)) {
+      showSimpleSnack(context, tr("Could not update following status!"));
+      return;
+    }
+
+    setState(() {
+      _group.following = !_group.following;
+
+      this.widget.onUpdated();
+    });
+  }
+}