Display the list of friends of the user

lib/ui/routes/home_route.dart

@@ -1,6 +1,8 @@
 import 'package:comunic/ui/screens/conversations_list_screen.dart';
+import 'package:comunic/ui/screens/friends_list_screen.dart';
 import 'package:comunic/ui/screens/menus_screen.dart';
 import 'package:comunic/ui/tiles/custom_bottom_navigation_bar_item.dart';
+import 'package:comunic/utils/intl_utils.dart';
 import 'package:flutter/material.dart';
 
 /// Main route of the application
@@ -52,6 +54,9 @@ class _HomeRouteState extends State<HomeRoute> {
         return ConversationsListScreen();
 
       case 1:
+        return FriendsListScreen();
+
+      case 2:
         return MenuScreen();
 
       default:
@@ -64,11 +69,15 @@ class _HomeRouteState extends State<HomeRoute> {
     return <BottomNavigationBarItem>[
       CustomNavigationBarItem(
         icon: Icon(Icons.chat),
-        title: Text("Conversations"),
+        title: Text(tr("Conversations")),
+      ),
+      CustomNavigationBarItem(
+        icon: Icon(Icons.group),
+        title: Text(tr("Friends")),
       ),
       CustomNavigationBarItem(
         icon: Icon(Icons.menu),
-        title: Text("Menu"),
+        title: Text(tr("Menu")),
       ),
     ];
   }

lib/ui/screens/friends_list_screen.dart

@@ -0,0 +1,122 @@
+import 'package:comunic/helpers/friends_helper.dart';
+import 'package:comunic/helpers/users_helper.dart';
+import 'package:comunic/lists/friends_list.dart';
+import 'package:comunic/lists/users_list.dart';
+import 'package:comunic/ui/tiles/accepted_friend_tile.dart';
+import 'package:comunic/ui/tiles/pending_friend_tile.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';
+
+/// Friends list screen
+///
+/// Display the list of friends of the current user
+///
+/// @author Pierre HUBERT
+
+enum _ErrorsLevel { NONE, MINOR, MAJOR }
+
+class FriendsListScreen extends StatefulWidget {
+  @override
+  State<StatefulWidget> createState() => _FriendsListScreenState();
+}
+
+class _FriendsListScreenState extends SafeState<FriendsListScreen> {
+  /// Helpers
+  final _friendsHelper = FriendsHelper();
+  final _usersHelper = UsersHelper();
+
+  /// Widget members
+  _ErrorsLevel _error = _ErrorsLevel.NONE;
+  FriendsList _friendsList;
+  UsersList _usersInfo;
+  bool _loading = true;
+
+  /// Useful setters
+  set error(_ErrorsLevel err) => setState(() => _error = err);
+
+  set loading(bool loading) => setState(() => _loading = loading);
+
+  void _gotError() =>
+      error = _friendsList == null ? _ErrorsLevel.MAJOR : _ErrorsLevel.MINOR;
+
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    _loadList();
+  }
+
+  /// Load the list of friends
+  Future<void> _loadList() async {
+    error = _ErrorsLevel.NONE;
+    loading = true;
+
+    // Get the list of friends
+    final list = await _friendsHelper.downloadList();
+
+    // Check for errors
+    if (list == null) return _gotError();
+
+    // Get information about related users
+    final users = await _usersHelper.getUsersInfo(list.usersId);
+
+    // Check for errors
+    if (users == null) return _gotError();
+
+    // Apply new information
+    setState(() {
+      _friendsList = list;
+      _usersInfo = users;
+    });
+    loading = false;
+    error = _ErrorsLevel.NONE;
+  }
+
+  /// Build and return loading error
+  Widget _buildError() =>
+      buildErrorCard(
+        tr("Could not load your list of friends!"),
+        actions: [
+          FlatButton(
+            onPressed: _loadList,
+            child: Text(
+              tr("Retry").toUpperCase(),
+              style: TextStyle(color: Colors.white),
+            ),
+          ),
+        ],
+      );
+
+  @override
+  Widget build(BuildContext context) {
+    if (_error == _ErrorsLevel.MAJOR) return _buildError();
+    if (_friendsList == null) return buildCenteredProgressBar();
+
+    return Column(
+      children: <Widget>[
+
+        // Check for errors
+        Container(child: _error != _ErrorsLevel.NONE ? _buildError() : null),
+
+        // Check if loading
+        Container(child: _loading ? CircularProgressIndicator() : 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),
+          ) : PendingFriendTile(
+            friend: _friendsList[i],
+            user: _usersInfo.getUser(_friendsList[i].id),
+            onRespond: (friend, accept){},
+          )),
+        ),
+
+      ],
+    );
+  }
+}

lib/ui/tiles/accepted_friend_tile.dart

@@ -0,0 +1,39 @@
+import 'package:comunic/models/friend.dart';
+import 'package:comunic/models/user.dart';
+import 'package:comunic/ui/widgets/account_image_widget.dart';
+import 'package:comunic/utils/date_utils.dart';
+import 'package:comunic/utils/intl_utils.dart';
+import 'package:flutter/material.dart';
+
+/// Accepted friend tile
+///
+/// @author Pierre HUBERT
+
+class AcceptedFriendTile extends StatelessWidget {
+  final Friend friend;
+  final User user;
+
+  const AcceptedFriendTile(
+      {Key key, @required this.friend, @required this.user})
+      : assert(friend != null),
+        assert(user != null),
+        super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return ListTile(
+      leading: AccountImageWidget(user: user),
+      title: Text(user.displayName),
+      subtitle: friend.isConnected
+          ? Text(
+              tr(
+                "Online",
+              ),
+              style: TextStyle(color: Colors.green),
+            )
+          : Text(
+        diffTimeFromNowToStr(friend.lastActive),
+            ),
+    );
+  }
+}

lib/ui/tiles/pending_friend_tile.dart

@@ -0,0 +1,64 @@
+import 'package:comunic/models/friend.dart';
+import 'package:comunic/models/user.dart';
+import 'package:comunic/ui/widgets/account_image_widget.dart';
+import 'package:comunic/utils/intl_utils.dart';
+import 'package:flutter/material.dart';
+
+/// Pending friend tile
+///
+/// @author Pierre HUBERT
+
+typedef RespondFriendshipRequestCallback = void Function(Friend, bool);
+
+class PendingFriendTile extends StatelessWidget {
+  final Friend friend;
+  final User user;
+  final RespondFriendshipRequestCallback onRespond;
+
+  const PendingFriendTile(
+      {Key key,
+      @required this.friend,
+      @required this.user,
+      @required this.onRespond})
+      : assert(friend != null),
+        assert(user != null),
+        assert(onRespond != null),
+        super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return ListTile(
+      leading: AccountImageWidget(
+        user: user,
+      ),
+      isThreeLine: true,
+      title: Text(user.fullName),
+      subtitle: Container(
+        height: 30.0,
+        margin: EdgeInsets.only(top: 8.0),
+        child: Row(
+          mainAxisAlignment: MainAxisAlignment.end,
+          children: <Widget>[
+            FlatButton(
+              child: Text(
+                tr("Accept").toUpperCase(),
+                style: TextStyle(color: Colors.white),
+              ),
+              color: Colors.green,
+              onPressed: () => onRespond(friend, true),
+            ),
+            Container(width: 8.0,),
+            FlatButton(
+              child: Text(
+                tr("Reject").toUpperCase(),
+                style: TextStyle(color: Colors.white),
+              ),
+              color: Colors.red,
+              onPressed: () => onRespond(friend, false),
+            )
+          ],
+        ),
+      ),
+    );
+  }
+}

lib/ui/widgets/safe_state.dart

@@ -0,0 +1,13 @@
+import 'package:flutter/material.dart';
+
+/// Little State hack to avoid issues
+///
+/// @author Pierre HUBERT
+
+abstract class SafeState<T extends StatefulWidget> extends State<T> {
+  @override
+  void setState(fn) {
+    if(mounted)
+      super.setState(fn);
+  }
+}