How to reset ListView children - flutter

Question

I am using a ListView with selectable items similar to this example.
Each stateful widget in the ListView has a _selected boolean to determine it's selected status which is flipped when the item is tapped.
When the user is in selection mode, there is a "back" option in the app bar. Determining when the back button is pressed and handling underlying core logic is working fine. I just want to reset the _selected flag on each individual list item so that they no long display as selected. You can see in the included gif that once back is pressed, the ListView items remain selected.
I am obviously missing something extremely basic.
The underlying question is, how do I trigger a reset of a ListView children items programatically.
Edit: Sample code added
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'List selection demo',
home: new MyHomePage(title: 'List selection demo'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => new _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final List<String> playerList = [
"Player 1",
"Player 2",
"Player 3",
"Player 4"
];
List<String> selectedPlayers = [];
bool longPressFlag = false;
void longPress() {
setState(() {
if (selectedPlayers.isEmpty) {
longPressFlag = false;
} else {
longPressFlag = true;
}
});
}
void clearSelections(){
setState(() {
selectedPlayers.clear();
});
}
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text(selectedPlayers.length == 0?widget.title: selectedPlayers.length.toString() + " selected"),
leading: selectedPlayers.length == 0? null: new IconButton(
icon: new Icon(Icons.arrow_back),
onPressed: () {clearSelections();
})),
body: ListView.builder(
itemBuilder: (BuildContext context, int index) {
return new PlayerItem(
playerName: playerList[index],
longPressEnabled: longPressFlag,
callback: () {
if (selectedPlayers.contains(playerList[index])) {
selectedPlayers.remove(playerList[index]);
} else {
selectedPlayers.add(playerList[index]);
}
longPress();
});
},
itemCount: playerList.length,
));
}
}
class PlayerItem extends StatefulWidget {
final String playerName;
final bool longPressEnabled;
final VoidCallback callback;
const PlayerItem(
{Key key, this.playerName, this.longPressEnabled, this.callback})
: super(key: key);
#override
_PlayerItemState createState() => new _PlayerItemState();
}
class _PlayerItemState extends State<PlayerItem> {
bool selected = false;
#override
Widget build(BuildContext context) {
return new GestureDetector(
onLongPress: () {
setState(() {
selected = !selected;
});
widget.callback();
},
onTap: () {
if (widget.longPressEnabled) {
setState(() {
selected = !selected;
});
widget.callback();
} else {
final snackBar = SnackBar(content: Text(widget.playerName + " tapped"));
Scaffold.of(context).showSnackBar(snackBar);
}
},
child: new Card(
color: selected ? Colors.grey[300] : Colors.white,
elevation: selected ? 4.0 : 1.0,
margin: const EdgeInsets.all(4.0),
child: new ListTile(
leading: new CircleAvatar(
child: new Text(widget.playerName.substring(0, 1)),
),
title: new Text(widget.playerName),
)));
}
}

Answer 1

You have to call following method for reset widgets.
setState(() {
});