TodoList.dart

import 'package:flutter/material.dart';
import 'package:meta/meta.dart';

class NewTodoList extends StatefulWidget {
  NewTodoListState createState() => new NewTodoListState();
}
class NewTodoListState extends State<NewTodoList> {
  List _list = new List();
  TextEditingController _addedController = new TextEditingController();
  Widget addedTile(){
    return new Row(
      children: <Widget>[
        new Expanded(child: new TextField(controller: _addedController,),),
        new IconButton(icon: new Icon(Icons.add), onPressed: () => add())
      ],
    );
  }
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'NewTodoList',
      home: new Scaffold(
        appBar: new AppBar(
          title: new Text('New todoList'),
        ),
        body: new Column(
          children: <Widget>[
            addedTile(),
            new ListView.builder(
                itemCount: _list.length,
                shrinkWrap: true,
                itemBuilder: (context, int index){
                    return TodoTile(
                        _list[index],
                        index,
                        onDelete: this._delete,
                    );
                }
            )
          ],
        ),
      ),
    );
  }

  void _delete(int index) {
    print('called delete');
    print(index);
    setState(() {
      _list.removeAt(index);
    });
    print(_list);
  }
  add() {
    setState(() {
      _list.add(_addedController.text);
    });
    print(_list);
  }
}

class TodoTile extends StatefulWidget {
  String _data;
  int _index;
  final ValueChanged<int> onDelete;
  TodoTile(String data, int index ,{ @required this.onDelete }){
    _data = data;
    _index = index;
  }
  TodoTileState createState() => new TodoTileState(_data, _index);
}

class TodoTileState extends State<TodoTile>{
  String _data;
  int _index;
  bool _writable = false;
  TextEditingController _controller;
  TodoTileState(String data, int index){
    _data = data;
    _controller = new TextEditingController(text: _data);
    _index = index;
//    _data = widget._data;
//    _controller = new TextEditingController(text: _data);
  }
  void del(){
    widget.onDelete(_index);
  }

  @override
  Widget build(BuildContext context) {
    return ( !_writable ) ?
    new Row(children: <Widget>[
      new Expanded(child: new Text(_controller.text)),
      new IconButton(icon: new Icon(Icons.edit), onPressed: (){setState(() {
        _writable = true;
      });}),
      new IconButton(icon: new Icon(Icons.delete), onPressed: (){
del();
      }),
    ])
        :
    new Row(children: <Widget>[
      new Expanded(child: new TextField(controller: _controller,)),
//      new IconButton(icon: new Icon(Icons.edit), onPressed: null),
      new IconButton(icon: new Icon(Icons.done), onPressed: (){
        setState(() {
        _writable = false;
      });
      }),
    ]);
  }
}

class TodoTile extends StatelessWidget{
  String _data;
  int _index;
  final ValueChanged<int> onDelete;
  TodoTile(String data, int index ,{ @required this.onDelete }){
    _data = data;
    _index = index;
  }

  @override
  Widget build(BuildContext context) {
   /* return new Row(children: <Widget>[
      new IconButton(icon: new Icon(Icons.edit), onPressed: null),
      new IconButton(icon: new Icon(Icons.delete), onPressed:(){}),
    ]);*/
   return RaisedButton(child:new Text(_data),onPressed: (){
     this.onDelete(_index);
   },);
  }

}