Todo App

main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(TasksApp());
}

class Task {
  bool done;
  String description;
  Task(this.done, this.description);
}

class TasksApp extends StatefulWidget {
  @override
  _TasksAppState createState() => _TasksAppState();
}

class _TasksAppState extends State<TasksApp> {
  List<Task> tasks = [
    Task(false, 'Feed the cat'),
    Task(false, 'Cook breakfast'),
  ];

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: SafeArea(
          child: Scrollbar(
            child: ReorderableListView(
              header: Header('My Tasks'),
              onReorder: (oldIndex, newIndex) {
                setState(() {
                  if (oldIndex < newIndex) {
                    // removing the item at oldIndex will shorten the list by 1.
                    newIndex -= 1;
                  }
                  final Task element = tasks.removeAt(oldIndex);
                  tasks.insert(newIndex, element);
                });
              },
              children: [
                ...tasks.map(
                      (t) => Dismissible(
                    key: ValueKey(t),
                    child: TaskView(task: t),
                    onDismissed: (direction) {
                      setState(() {
                        tasks.remove(t);
                      });
                    },
                    background: Container(
                      color: Colors.blue,
                    ),
                  ),
                ),
              ],
            ),
          ),
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () {
            setState(() {
              tasks.insert(0, Task(false, ''));
            });
          },
          child: Icon(Icons.add),
        ),
      ),
    );
  }
}


class TaskView extends StatefulWidget {
  final Task task;

  TaskView({
    @required this.task,
  }) : super(key: ValueKey(task));

  @override
  _TaskViewState createState() => _TaskViewState();
}

class _TaskViewState extends State<TaskView> {
  static const textStyle = TextStyle(fontSize: 16, color: Colors.black);
  TextEditingController textController;
  FocusNode focusNode;

  @override
  void initState() {
    super.initState();

    textController = TextEditingController()
      ..text = widget.task.description
      ..addListener(() {
        setState(() {
          widget.task.description = textController.text;
        });
      });
    focusNode = FocusNode();
  }

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        Checkbox(
          value: widget.task.done,
          onChanged: (checked) {
            setState(() {
              widget.task.done = checked;
            });
          },
        ),
        Expanded(
          child: TextField(
            controller: textController,
            focusNode: focusNode,
            style: textStyle,
            cursorColor: Colors.blue,
            decoration: InputDecoration(
              enabledBorder: InputBorder.none,
              focusedBorder: InputBorder.none,
            ),
          ),
        ),
        Padding(
          padding: const EdgeInsets.all(4.0),
          child: Icon(
            Icons.drag_handle,
            color: Colors.grey,
          ),
        )
      ],
    );
  }
}

class Header extends StatelessWidget {
  final String title;
  static const TextStyle headerStyle =
  TextStyle(fontSize: 32, fontWeight: FontWeight.w600);

  Header(this.title);

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: EdgeInsets.fromLTRB(12, 8, 12, 8),
      child: Column(
        children: [
          Text(
            title,
            style: headerStyle,
          ),
        ],
      ),
    );
  }
}