Can block the creation of new responses on a survey

lib/ui/widgets/survey_widget.dart

@@ -1,6 +1,7 @@
 import 'package:comunic/helpers/survey_helper.dart';
 import 'package:comunic/models/survey.dart';
 import 'package:comunic/models/survey_choice.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';
@@ -21,7 +22,7 @@ class SurveyWidget extends StatefulWidget {
   _SurveyWidgetState createState() => _SurveyWidgetState();
 }
 
-class _SurveyWidgetState extends State<SurveyWidget> {
+class _SurveyWidgetState extends SafeState<SurveyWidget> {
   final SurveyHelper _helper = SurveyHelper();
 
   Survey get survey => widget.survey;
@@ -42,6 +43,12 @@ class _SurveyWidgetState extends State<SurveyWidget> {
           style: TextStyle(fontWeight: FontWeight.bold),
         ),
         _buildUserResponse(),
+
+        // Offer to block the creation of new responses, if possible
+        survey.allowNewChoicesCreation
+            ? _buildBlockNewResponsesLink()
+            : Container(),
+
         survey.hasResponses ? _buildChart() : _buildNoResponseNotice(),
       ],
     );
@@ -109,6 +116,11 @@ class _SurveyWidgetState extends State<SurveyWidget> {
     );
   }
 
+  Widget _buildBlockNewResponsesLink() => InkWell(
+        onTap: _blockNewChoices,
+        child: Text(tr("Block the creation of new responses")),
+      );
+
   Widget _buildChart() {
     return PieChart(
       dataMap: _buildDataMap(),
@@ -133,4 +145,21 @@ class _SurveyWidgetState extends State<SurveyWidget> {
       survey.setUserResponse(choice);
     });
   }
+
+  /// Block the creation of new choices on this survey
+  void _blockNewChoices() async {
+    try {
+      if (!await showConfirmDialog(
+          context: context,
+          message: tr("Do you really want to block new responses ?"))) return;
+
+      await SurveyHelper.blockNewChoicesCreation(survey.postID);
+
+      setState(() => survey.allowNewChoicesCreation = false);
+    } catch (e, s) {
+      print("Could not block the creation of new choices! $e\n$s");
+      showSimpleSnack(
+          context, tr("Could not block the creation of new choices!"));
+    }
+  }
 }