Add RefreshIndicator on friends screen

lib/ui/screens/friends_list_screen.dart

@@ -33,28 +33,31 @@ class _FriendsListScreenState extends SafeState<FriendsListScreen> {
   _ErrorsLevel _error = _ErrorsLevel.NONE;
   FriendsList _friendsList;
   UsersList _usersInfo;
-  bool _loading = true;
+  GlobalKey<RefreshIndicatorState> _refreshIndicatorKey =
+      GlobalKey<RefreshIndicatorState>();
 
   /// Useful setters
   set error(_ErrorsLevel err) => setState(() => _error = err);
 
-  set loading(bool loading) => setState(() => _loading = loading);
-
   void _gotError() {
-    loading = false;
     error = _friendsList == null ? _ErrorsLevel.MAJOR : _ErrorsLevel.MINOR;
   }
 
+
   @override
   void didChangeDependencies() {
     super.didChangeDependencies();
     _loadList();
   }
 
+  /// Refresh the list of friends
+  Future<void> _refreshList() async {
+    await _refreshIndicatorKey.currentState.show();
+  }
+
   /// Load the list of friends
   Future<void> _loadList() async {
     error = _ErrorsLevel.NONE;
-    loading = true;
 
     // Get the list of friends
     final list = await _friendsHelper.downloadList();
@@ -73,7 +76,6 @@ class _FriendsListScreenState extends SafeState<FriendsListScreen> {
       _friendsList = list;
       _usersInfo = users;
     });
-    loading = false;
     error = _ErrorsLevel.NONE;
   }
 
@@ -82,7 +84,7 @@ class _FriendsListScreenState extends SafeState<FriendsListScreen> {
         tr("Could not load your list of friends!"),
         actions: [
           FlatButton(
-            onPressed: _loadList,
+            onPressed: _refreshList,
             child: Text(
               tr("Retry").toUpperCase(),
               style: TextStyle(color: Colors.white),
@@ -96,43 +98,33 @@ class _FriendsListScreenState extends SafeState<FriendsListScreen> {
     if (_error == _ErrorsLevel.MAJOR) return _buildError();
     if (_friendsList == null) return buildCenteredProgressBar();
 
-    return Stack(
+    return Column(
       children: <Widget>[
-        Column(
-          children: <Widget>[
-            // Check for errors
-            Container(
-                child: _error != _ErrorsLevel.NONE ? _buildError() : null),
+        // Check for errors
+        Container(child: _error != _ErrorsLevel.NONE ? _buildError() : null),
 
-            // List of friends
-            Expanded(
-              child: ListView.builder(
-                  itemCount: _friendsList.length,
-                  itemBuilder: (c, i) => _friendsList[i].accepted
-                      ? AcceptedFriendTile(
-                          friend: _friendsList[i],
-                          user: _usersInfo.getUser(_friendsList[i].id),
-                          onOpenPrivateConversation: _openPrivateConversation,
-                          onSetFollowing: _setFollowingFriend,
-                          onRequestDelete: _deleteFriend,
-                        )
-                      : PendingFriendTile(
-                          friend: _friendsList[i],
-                          user: _usersInfo.getUser(_friendsList[i].id),
-                          onRespond: _respondRequest,
-                        )),
-            ),
-          ],
-        ),
-
-        // Check if loading
-        Positioned(
-          child: Container(
-              child:
-                  _loading ? Center(child: CircularProgressIndicator()) : null),
-          top: 16.0,
-          left: 0.0,
-          right: 0.0,
+        // List of friends
+        Expanded(
+          child: RefreshIndicator(
+            key: _refreshIndicatorKey,
+            onRefresh: _loadList,
+            child: ListView.builder(
+                physics: AlwaysScrollableScrollPhysics(),
+                itemCount: _friendsList.length,
+                itemBuilder: (c, i) => _friendsList[i].accepted
+                    ? AcceptedFriendTile(
+                        friend: _friendsList[i],
+                        user: _usersInfo.getUser(_friendsList[i].id),
+                        onOpenPrivateConversation: _openPrivateConversation,
+                        onSetFollowing: _setFollowingFriend,
+                        onRequestDelete: _deleteFriend,
+                      )
+                    : PendingFriendTile(
+                        friend: _friendsList[i],
+                        user: _usersInfo.getUser(_friendsList[i].id),
+                        onRespond: _respondRequest,
+                      )),
+          ),
         ),
       ],
     );
@@ -140,23 +132,19 @@ class _FriendsListScreenState extends SafeState<FriendsListScreen> {
 
   /// Respond to friendship request
   Future<void> _respondRequest(Friend f, bool accept) async {
-    loading = true;
-
     if (!await _friendsHelper.respondRequest(f.id, accept))
       showSimpleSnack(context, tr("Could not respond to friendship request!"));
 
     // Load the list of friends again
-    _loadList();
+    _refreshList();
   }
 
   /// Update following status of a friend
   Future<void> _setFollowingFriend(Friend friend, bool follow) async {
-    loading = true;
-
     if (!await _friendsHelper.setFollowing(friend.id, follow))
       showSimpleSnack(context, tr("Could not update following status!"));
 
-    _loadList();
+    _refreshList();
   }
 
   /// Handles deletion request of a friend
@@ -186,19 +174,16 @@ class _FriendsListScreenState extends SafeState<FriendsListScreen> {
     if (choice == null || !choice) return;
 
     // Forward the request to the server
-    loading = true;
     if (!await _friendsHelper.removeFriend(f.id))
       showSimpleSnack(
           context, tr("Could not delete this person from your friends list!"));
 
     // Refresh list
-    _loadList();
+    _refreshList();
   }
 
   /// Open a private conversation for a given [friend]
   Future<void> _openPrivateConversation(Friend friend) async {
-    loading = true;
     await openPrivateConversation(context, friend.id);
-    loading = false;
   }
 }