Can create a group

lib/helpers/groups_helper.dart

@@ -126,6 +126,17 @@ class GroupsHelper {
           .map((f) => cast<int>(f))
           .toSet();
 
+  /// Create a new group
+  ///
+  /// Throws in case of failure
+  static Future<int> create(String name) async {
+    final result = await APIRequest.withLogin("groups/create")
+        .addString("name", name)
+        .execWithThrow();
+
+    return result.getObject()["id"];
+  }
+
   /// Perform a simple membership request
   Future<bool> _simpleMembershipRequest(int groupID, String uri,
           {Map<String, String> args}) async =>

lib/ui/screens/groups_list_screen.dart

@@ -54,15 +54,20 @@ class _GroupsListScreenState extends SafeState<GroupsListScreen> {
           onRefresh: () => this._refreshList(),
           child: _groups == null
               ? Container()
-              : ListView(
+              : Stack(children: [_buildGroupsList(), _buildCreateButton()]),
+        ))
+      ],
+    );
+  }
+
+  Widget _buildGroupsList() => ListView(
         children: _groups.values
             .map((g) => ListTile(
                   leading: GroupIcon(group: g),
                   title: Text(g.displayName),
                   subtitle: GroupMembershipWidget(
                     group: g,
-                              onUpdated: () =>
-                                  _refreshIndicatorKey.currentState.show(),
+                    onUpdated: () => _refreshIndicatorKey.currentState.show(),
                   ),
                   trailing: IconButton(
                       icon: Icon(Icons.delete),
@@ -70,11 +75,16 @@ class _GroupsListScreenState extends SafeState<GroupsListScreen> {
                   onTap: () => MainController.of(context).openGroup(g.id),
                 ))
             .toList(),
-                ),
-        ))
-      ],
       );
-  }
+
+  Widget _buildCreateButton() => Positioned(
+        right: 15,
+        bottom: 15,
+        child: FloatingActionButton(
+          child: Icon(Icons.add),
+          onPressed: _createGroup,
+        ),
+      );
 
   /// Refresh the list of groups
   Future<void> _refreshList() async {
@@ -109,4 +119,27 @@ class _GroupsListScreenState extends SafeState<GroupsListScreen> {
     // Refresh the list of groups
     _refreshIndicatorKey.currentState.show();
   }
+
+  /// Add a group
+  void _createGroup() async {
+    try {
+      final name = await askUserString(
+        context: context,
+        title: tr("Group name"),
+        message: tr("Name of the group to create"),
+        defaultValue: "",
+        hint: tr("Name of the group"),
+        maxLength: 50,
+      );
+
+      if (name == null) return;
+
+      final groupID = await GroupsHelper.create(name);
+
+      MainController.of(context).openGroup(groupID);
+    } catch (e, s) {
+      print("Could not create a new group! $e\n$s");
+      showSimpleSnack(context, tr("Could not create a new group!"));
+    }
+  }
 }

lib/utils/ui_utils.dart

@@ -1,5 +1,6 @@
 import 'package:comunic/helpers/preferences_helper.dart';
 import 'package:comunic/ui/routes/full_screen_image.dart';
+import 'package:comunic/ui/widgets/dialogs/auto_sized_dialog_content_widget.dart';
 import 'package:comunic/utils/intl_utils.dart';
 import 'package:flutter/material.dart';
 import 'package:html/parser.dart';
@@ -86,12 +87,14 @@ Future<String> askUserString({
   @required String message,
   @required String defaultValue,
   @required String hint,
+  int maxLength = 200,
 }) async {
   assert(context != null);
   assert(title != null);
   assert(message != null);
   assert(defaultValue != null);
   assert(hint != null);
+  assert(maxLength != null);
 
   TextEditingController controller = TextEditingController(text: defaultValue);
 
@@ -99,16 +102,14 @@ Future<String> askUserString({
       context: context,
       builder: (c) => AlertDialog(
             title: Text(title),
-            content: Container(
-              height: MediaQuery.of(context).size.height - 50,
-              child: SingleChildScrollView(
+            content: AutoSizeDialogContentWidget(
               child: Column(
                 children: <Widget>[
                   Text(message),
                   TextField(
                     controller: controller,
                     maxLines: null,
-                      maxLength: 200,
+                    maxLength: maxLength,
                     keyboardType: TextInputType.text,
                     decoration: InputDecoration(
                       labelText: hint,
@@ -118,7 +119,6 @@ Future<String> askUserString({
                 ],
               ),
             ),
-            ),
             actions: <Widget>[
               FlatButton(
                 child: Text(tr("Cancel").toUpperCase()),