ListTile onLongPress Event Not working Flutter

Question

I encountered weird issue while creating a learning Todo App. I implemented TaskList Class and TaskTile class as below.

TaskList Class as below

import 'package:provider/provider.dart';
import 'package:todoey/Models/taskdata.dart';
import 'package:todoey/widgets/task_tile.dart';

class TasksList extends StatefulWidget {
  @override
  State<TasksList> createState() => _TasksListState();
}

class _TasksListState extends State<TasksList> {
  @override
  Widget build(BuildContext context) {
    return Consumer<TaskData>(builder: (context, taskData, child) {
      return ListView.builder(
        itemBuilder: (context, index) {
          final task = taskData.taskList[index];
          return TaskTile(
            longPressCallBack: () {
              taskData.deleteTask(task);
            },
            name: task.name,
            isChecked: task.isDone,
            checkBoxCallBack: (newValue) {
              taskData.updateTask(task);
            },
          );
        },
        itemCount: taskData.taskList.length,
      );
    });
  }
}

TaskTile Class as below

class TaskTile extends StatelessWidget {
  final bool? isChecked;
  final String name;
  final Function checkBoxCallBack;
  final Function longPressCallBack;

  TaskTile(
      {required this.name,
      this.isChecked,
      required this.checkBoxCallBack,
      required this.longPressCallBack});

  @override
  Widget build(BuildContext context) {
    return ListTile(
      title: Text(
        name,
        style: TextStyle(
          decoration: isChecked! ? TextDecoration.lineThrough : null,
        ),
      ),
      trailing: Checkbox(
        fillColor: MaterialStateProperty.all(Colors.lightBlueAccent),
        checkColor: Colors.white,
        value: isChecked!,
        onChanged: (newValue) {
          checkBoxCallBack(newValue);
        },
      ),
      onLongPress: () => longPressCallBack,
    );
  }
}

Now the problem is it doesn't call longPressCallBack of parent class i.e. TaskList class. I debugged and it calls onLongPress of TaskTile class but not calling callback to it's parent class and that is why deleteTask not working.

Answer 1

The problem is with this line onLongPress: () => longPressCallBack, on your TaskTile class. Here you are just invoking longPressCallBack closure reference instead of executing the closure function.

Solution:

Change that line to this : onLongPress: () => longPressCallBack(), or try directly passing function refrence to onLongPress property of ListTile like this onLongPress: longPressCallBack,