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

@@ -54,28 +54,38 @@ class _GroupsListScreenState extends SafeState<GroupsListScreen> {
           onRefresh: () => this._refreshList(),
           child: _groups == null
               ? Container()
-              : ListView(
-                  children: _groups.values
-                      .map((g) => ListTile(
-                            leading: GroupIcon(group: g),
-                            title: Text(g.displayName),
-                            subtitle: GroupMembershipWidget(
-                              group: g,
-                              onUpdated: () =>
-                                  _refreshIndicatorKey.currentState.show(),
-                            ),
-                            trailing: IconButton(
-                                icon: Icon(Icons.delete),
-                                onPressed: () => _deleteGroup(g)),
-                    onTap: () => MainController.of(context).openGroup(g.id),
-                          ))
-                      .toList(),
-                ),
+              : 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(),
+                  ),
+                  trailing: IconButton(
+                      icon: Icon(Icons.delete),
+                      onPressed: () => _deleteGroup(g)),
+                  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 {
     try {
@@ -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);
 
@@ -99,24 +102,21 @@ Future<String> askUserString({
       context: context,
       builder: (c) => AlertDialog(
             title: Text(title),
-            content: Container(
-              height: MediaQuery.of(context).size.height - 50,
-              child: SingleChildScrollView(
-                child: Column(
-                  children: <Widget>[
-                    Text(message),
-                    TextField(
-                      controller: controller,
-                      maxLines: null,
-                      maxLength: 200,
-                      keyboardType: TextInputType.text,
-                      decoration: InputDecoration(
-                        labelText: hint,
-                        alignLabelWithHint: true,
-                      ),
-                    )
-                  ],
-                ),
+            content: AutoSizeDialogContentWidget(
+              child: Column(
+                children: <Widget>[
+                  Text(message),
+                  TextField(
+                    controller: controller,
+                    maxLines: null,
+                    maxLength: maxLength,
+                    keyboardType: TextInputType.text,
+                    decoration: InputDecoration(
+                      labelText: hint,
+                      alignLabelWithHint: true,
+                    ),
+                  )
+                ],
               ),
             ),
             actions: <Widget>[