State management in flutter - dart

Question

I've created a flutter app where I'm managing array for todolist in app. I've can add the text by add button.
I've created a widget to show in list.
My question is how am i supposed manage the UI of individual.
Code:
import 'package:flutter/material.dart';
class TodoList extends StatefulWidget {
_TodoListState createState() => new _TodoListState();
}
class _TodoListState extends State<TodoList> {
List _list = new List();
Widget listTile({String data: '[Empty data]'}) {
bool _writable = false;
TextEditingController _textController = new TextEditingController(text: data);
String _text = _textController.text;
if(!_writable){
return new Row(
children: <Widget>[
new Expanded(
child: new Text(data)
),
new IconButton(icon: new Icon(Icons.edit),
onPressed: () {
// setState(() {
_writable = ! _writable;
print(_writable.toString());
// });
}),
new IconButton(icon: new Icon(Icons.remove_circle), onPressed: null),
],
);
} else {
return new Row(
children: <Widget>[
new Expanded(
child: new TextField( controller: _textController )
),
new IconButton(icon: new Icon(Icons.done), onPressed: null),
],
);
}
}
void addInList(String string) {
print(string);
setState(() {
_list.add(string);
});
print(_list);
}
void removeFromList(int index){
}
static final TextEditingController _textController = new TextEditingController();
String get _text => _textController.text;
#override
Widget build(BuildContext context) {
Widget adderTile = new Row(
children: <Widget>[
new Expanded(
child:
new TextField(
textAlign: TextAlign.center,
controller: _textController ,
decoration: new InputDecoration( hintText: 'New item.!' ),
),
),
new IconButton(icon: new Icon(Icons.add), onPressed: (){addInList(_text);}),
],
);
return new MaterialApp(
title: 'TodoList',
home: new Scaffold(
appBar: new AppBar(title: new Text('TodoList'),),
body: new Column(
children: <Widget>[
adderTile,
new ListView.builder(
shrinkWrap: true,
itemCount: _list.length,
itemBuilder: (context, int index){
return listTile(data: _list[index]);
}
),
],
),
),
);
}
}
if i change _writable inside setState then it rerenders widget and _writable becomes false again. if i do it without setState, then _writable becomes true but widget doesn't rerender.
P.S.: i don't want to add another array in to manage which is writable and which is not. Thanks in advance.

Answer 1

The variable
bool _writable = false;
is declared as local variable in the method listTile(), but should be moved next to List _list = new List(); to become a member variable. Then use setState() to set it and rebuild the view.
Edit:
You should create a dedicated StatefulWidget (TodoListEntry), having _writable as member as suggested above. Move almost the whole method body of listTile(...) to the build()-method of the TodoListEntryState, make the parameter String data also a member and pass the value via the constructor.