fix: redundant click prevention bug

app/lib/screens/study/tasks/intervention/checkmark_task_widget.dart

@@ -18,7 +18,7 @@ class CheckmarkTaskWidget extends StatefulWidget {
 }
 
 class _CheckmarkTaskWidgetState extends State<CheckmarkTaskWidget> {
-  DateTime _lastClickTime = DateTime.now();
+  DateTime? _lastClickTime;
   bool _isLoading = false;
 
   @override

app/lib/screens/study/tasks/observation/questionnaire_task_widget.dart

@@ -27,7 +27,7 @@ class QuestionnaireTaskWidget extends StatefulWidget {
 class _QuestionnaireTaskWidgetState extends State<QuestionnaireTaskWidget> {
   dynamic response;
   late bool responseValidator;
-  DateTime _lastClickTime = DateTime.now();
+  DateTime? _lastClickTime;
   bool _isLoading = false;
   final GlobalKey<FormState> formKey = GlobalKey<FormState>();
 
@@ -86,12 +86,8 @@ class _QuestionnaireTaskWidgetState extends State<QuestionnaireTaskWidget> {
               backgroundColor: WidgetStateProperty.all<Color>(Colors.green),
             ),
             onPressed: () async {
-              if (isRedundantClick(_lastClickTime)) {
-                return;
-              }
-              if (!formKey.currentState!.validate()) {
-                return;
-              }
+              if (isRedundantClick(_lastClickTime)) return;
+              if (!formKey.currentState!.validate()) return;
               setState(() {
                 _isLoading = true;
                 _lastClickTime = DateTime.now();

app/lib/util/misc.dart

@@ -1,7 +1,8 @@
 bool isRedundantClick(
-  DateTime lastClickTime, {
-  Duration interval = const Duration(seconds: 2),
+  DateTime? lastClickTime, {
+  Duration interval = const Duration(seconds: 1),
 }) {
+  if (lastClickTime == null) return false;
   final now = DateTime.now();
   if (now.difference(lastClickTime) > interval) {
     return false;