Improve user access denied screen

lib/ui/screens/user_access_denied_screen.dart

@@ -5,8 +5,9 @@ import 'package:comunic/models/user.dart';
 import 'package:comunic/ui/routes/main_route/main_route.dart';
 import 'package:comunic/ui/widgets/FrienshipStatusWidget.dart';
 import 'package:comunic/ui/widgets/account_image_widget.dart';
+import 'package:comunic/ui/widgets/async_screen_widget.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';
 
 /// User access denied screen
@@ -24,94 +25,67 @@ class UserAccessDeniedScreen extends StatefulWidget {
   _UserAccessDeniedScreenState createState() => _UserAccessDeniedScreenState();
 }
 
-class _UserAccessDeniedScreenState extends State<UserAccessDeniedScreen> {
+class _UserAccessDeniedScreenState extends SafeState<UserAccessDeniedScreen> {
   final UsersHelper usersHelper = UsersHelper();
   final FriendsHelper friendsHelper = FriendsHelper();
 
-  GlobalKey<RefreshIndicatorState> _refreshIndicatorKey =
-      GlobalKey<RefreshIndicatorState>();
+  final _key = GlobalKey<AsyncScreenWidgetState>();
 
   FriendStatus _status;
   User _user;
-  bool _error = false;
-
-  void setError(bool e) => setState(() => _error = e);
-
-  @override
-  void didChangeDependencies() {
-    super.didChangeDependencies();
-    refresh();
-  }
 
   Future<void> refresh() async {
-    try {
-      final status = await friendsHelper.getFriendshipStatus(widget.userID);
-      final user = await usersHelper.getSingleWithThrow(widget.userID);
+    final status = await friendsHelper.getFriendshipStatus(widget.userID);
+    final user = await usersHelper.getSingleWithThrow(widget.userID);
 
-      // Check if the two users are friend now
-      if (status.areFriend) {
-        final controller = MainController.of(context);
-        controller.popPage();
-        controller.openUserPage(widget.userID);
-      }
-
-      setState(() {
-        _status = status;
-        _user = user;
-      });
-    } catch (e) {
-      setError(true);
+    // Check if the two users are friend now
+    if (status.areFriend) {
+      final controller = MainController.of(context);
+      controller.popPage();
+      controller.openUserPage(widget.userID);
     }
+
+    _status = status;
+    _user = user;
   }
 
   @override
   Widget build(BuildContext context) {
-    if (!_error && _status == null) return buildLoadingPage(showAppBar: true);
+    return AsyncScreenWidget(
+        key: _key,
+        onReload: refresh,
+        onBuild: _buildPage,
+        errorMessage: tr("Could not load friendship information!"));
+  }
 
-    return Scaffold(
-      appBar: AppBar(
-        title: Text(_error ? "Error" : _user.displayName),
-      ),
-      body: RefreshIndicator(
-        key: _refreshIndicatorKey,
-        onRefresh: refresh,
-        child: ListView.builder(
-          itemBuilder: (c, i) => _scrollBuild(),
-          itemCount: 1,
+  Widget _buildPage() {
+    final size = MediaQuery.of(context).size;
+    return Container(
+      constraints: BoxConstraints.loose(size),
+      child: SingleChildScrollView(
+        child: Padding(
+          padding: const EdgeInsets.all(8.0),
+          child: Column(
+            crossAxisAlignment: CrossAxisAlignment.center,
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: <Widget>[
+              AccountImageWidget(
+                user: _user,
+                width: 75,
+              ),
+              Text(
+                _user.displayName,
+                style: TextStyle(fontSize: 25.0),
+              ),
+              Text(tr("This account is private.")),
+              FriendshipStatusWidget(
+                status: _status,
+                onFriendshipUpdated: () => _key.currentState.refresh(),
+              )
+            ],
+          ),
         ),
       ),
     );
   }
-
-  Widget _scrollBuild() {
-    if (_error) return _buildError();
-
-    return _buildPage();
-  }
-
-  Widget _buildError() {
-    return buildErrorCard("Could get information about your friendship!");
-  }
-
-  Widget _buildPage() {
-    return Center(
-      child: Column(
-        children: <Widget>[
-          AccountImageWidget(
-            user: _user,
-            width: 75,
-          ),
-          Text(
-            _user.displayName,
-            style: TextStyle(fontSize: 25.0),
-          ),
-          Text(tr("This account is private.")),
-          FriendshipStatusWidget(
-            status: _status,
-            onFriendshipUpdated: () => _refreshIndicatorKey.currentState.show(),
-          )
-        ],
-      ),
-    );
-  }
 }