Use RefreshIndicator for conversations list

lib/ui/screens/conversations_list_screen.dart

@@ -25,7 +25,8 @@ class _ConversationScreenState extends State<ConversationsListScreen> {
   final UsersHelper _usersHelper = UsersHelper();
   ConversationsList _list;
   LoadErrorLevel _error = LoadErrorLevel.NONE;
-  bool _loading = true;
+  final GlobalKey<RefreshIndicatorState> _refreshIndicatorKey =
+      GlobalKey<RefreshIndicatorState>();
 
   @override
   void didChangeDependencies() {
@@ -35,14 +36,11 @@ class _ConversationScreenState extends State<ConversationsListScreen> {
 
   @override
   void setState(fn) {
-    if(mounted)
-      super.setState(fn);
+    if (mounted) super.setState(fn);
   }
 
   void setError(LoadErrorLevel err) => setState(() => _error = err);
 
-  void setLoading(bool loading) => setState(() => _loading = loading);
-
   /// Get the list of conversations, once from the cache, once from the server
   Future<void> _loadConversations() async {
     await _loadConversationsList(true);
@@ -50,14 +48,12 @@ class _ConversationScreenState extends State<ConversationsListScreen> {
   }
 
   void _gotLoadingError() {
-    setLoading(false);
     setError(_list == null ? LoadErrorLevel.MAJOR : LoadErrorLevel.MINOR);
   }
 
   /// Load the list of conversations
   Future<void> _loadConversationsList(bool cached) async {
     setError(LoadErrorLevel.NONE);
-    setLoading(true);
 
     //Get the list of conversations
     var list;
@@ -73,13 +69,10 @@ class _ConversationScreenState extends State<ConversationsListScreen> {
 
     if (list.users == null) return _gotLoadingError();
 
-
     //Save list
     setState(() {
       _list = list;
     });
-
-    setLoading(false);
   }
 
   /// Build an error card
@@ -88,7 +81,7 @@ class _ConversationScreenState extends State<ConversationsListScreen> {
       tr("Could not retrieve the list of conversations!"),
       actions: <Widget>[
         FlatButton(
-          onPressed: () => _loadConversationsList(false),
+          onPressed: () => _refreshIndicatorKey.currentState.show(),
           child: Text(
             tr("Retry").toUpperCase(),
             style: TextStyle(
@@ -177,20 +170,25 @@ class _ConversationScreenState extends State<ConversationsListScreen> {
               child: _error == LoadErrorLevel.MINOR ? _buildErrorCard() : null,
             ),
             Expanded(
-              child: ListView.builder(
-                controller: ScrollController(),
-                itemBuilder: (context, index) {
-                  return ConversationTile(
-                    conversation: _list.elementAt(index),
-                    usersList: _list.users,
-                    onOpen: (c) {
-                      _openConversation(context, c.id);
-                    },
-                    onRequestUpdate: _updateConversation,
-                    onRequestDelete: _requestDeleteConversation,
-                  );
-                },
-                itemCount: _list.length,
+              child: RefreshIndicator(
+                onRefresh: () => _loadConversationsList(false),
+                key: _refreshIndicatorKey,
+                child: ListView.builder(
+                  physics: AlwaysScrollableScrollPhysics(),
+                  controller: ScrollController(),
+                  itemBuilder: (context, index) {
+                    return ConversationTile(
+                      conversation: _list.elementAt(index),
+                      usersList: _list.users,
+                      onOpen: (c) {
+                        _openConversation(context, c.id);
+                      },
+                      onRequestUpdate: _updateConversation,
+                      onRequestDelete: _requestDeleteConversation,
+                    );
+                  },
+                  itemCount: _list.length,
+                ),
               ),
             ),
           ],
@@ -205,20 +203,6 @@ class _ConversationScreenState extends State<ConversationsListScreen> {
             child: Icon(Icons.add),
           ),
         ),
-
-        // Loading indicator
-        Positioned(
-          top: 8.0,
-          left: 0.0,
-          right: 0.0,
-          child: Container(
-            child: !_loading
-                ? null
-                : Center(
-                    child: CircularProgressIndicator(),
-                  ),
-          ),
-        )
       ],
     );
   }