validate form before saving

lib/pages/task_edit_page.dart

@@ -191,32 +191,34 @@ class _TaskEditPageState extends State<TaskEditPage> {
   }
 
   void onSavePressed() {
-    Navigator.of(context).pop(
+    if (formKey.currentState!.validate()) {
-      CreateTaskRequest(
+      Navigator.of(context).pop(
-        title: titleController.text,
+        CreateTaskRequest(
-        description: descriptionController.text,
+          title: titleController.text,
-        start: null,
+          description: descriptionController.text,
-        due: DateTime.tryParse(
+          start: null,
-          '${dueDateController.text} ${dueTimeController.text}'.trim(),
+          due: DateTime.tryParse(
+            '${dueDateController.text} ${dueTimeController.text}'.trim(),
+          ),
+          isCompleted: false,
+          category: categoryController.text,
+          subtasks: [],
+          url: urlController.text,
+          alarms: alarmRequests.map<Alarm>((e) {
+            if (e is CreateFixedTimeAlarmRequest) {
+              return e.toAlarm(generateId());
+            }
+            if (e is CreateRelativeTimeAlarmRequest) {
+              return e.toAlarm(generateId());
+            }
+            if (e is LocationAlarm) {
+              return e.toAlarm(generateId());
+            }
+            throw TypeError();
+          }).toList(),
         ),
-        isCompleted: false,
+      );
-        category: categoryController.text,
+    }
-        subtasks: [],
-        url: urlController.text,
-        alarms: alarmRequests.map<Alarm>((e) {
-          if (e is CreateFixedTimeAlarmRequest) {
-            return e.toAlarm(generateId());
-          }
-          if (e is CreateRelativeTimeAlarmRequest) {
-            return e.toAlarm(generateId());
-          }
-          if (e is LocationAlarm) {
-            return e.toAlarm(generateId());
-          }
-          throw TypeError();
-        }).toList(),
-      ),
-    );
   }
 
   void onPopInvoked(bool didPop, Object? result) {