How do you display a bunch of the same widget in Flutter? - flutter

Question

I have created a GameBoard widget that I want to populate with 16 GameTile widgets that I have also created. For the purpose of the game the GameTile widgets are using the Positioned widget. How do I generate 16 tiles without having to type out each one?
Here is my GameBoard widget code:
return Container(
width: _myScreenWidth * 0.80,
height: _myScreenWidth * 0.80,
child: Stack(
children: [
List.generate(16, (index) {
return GameTile(value: tileValue[index], color: tileColor[index], x: tileXCoordinate[index], y: tileYCoordinate[index]);
}),
],
),
);
Here is my GameTile code:
return Positioned(
left: x,
bottom: y,
child: PhysicalModel(
borderRadius: BorderRadius.circular(10.0),
color: color,
child: Container(
width: _tileWidth,
height: _tileHeight,
child: Center(
child: Text(
value.toString(),
textAlign: TextAlign.center,
style: new TextStyle(
fontSize: _myScreenWidth * 0.07,
color: backgroundColor,
fontWeight: FontWeight.bold,
),
),
),
),
),
);
Any help is much appreciated.

Answer 1

Use a function and a List to store your generated widget
and display it with function
code snippet
List<Widget> getList() {
List<Widget> widgeList = [];
for (var i = 0; i < 10; i++) {
for (var item in widget.items) {
widgeList.add(Positioned(
left: item.x,
bottom: item.y,
child: PhysicalModel(
borderRadius: BorderRadius.circular(10.0),
color: Colors.blueAccent,
child: Container(
width: item.tileWidth,
height: item.tileHeight,
child: Center(
child: Text(
item.value,
textAlign: TextAlign.center,
style: new TextStyle(
//fontSize: _myScreenWidth * 0.07,
//color: backgroundColor,
fontWeight: FontWeight.bold,
),
),
),
),
),
));
}
}
return widgeList;
}
...
body: Stack(
children: getList(),
),
and your game class look like this, it just a demo I did not recreate all your attribute
class Game {
double x;
double y;
double tileWidth;
double tileHeight;
String value;
Game({
this.x,
this.y,
this.tileWidth,
this.tileHeight,
this.value,
});
factory Game.fromJson(Map<String, dynamic> json) => Game(
x: json["x"],
y: json["y"],
tileWidth: json["tileWidth"],
tileHeight: json["tileHeight"],
value: json["value"],
);
Map<String, dynamic> toJson() => {
"x": x,
"y": y,
"tileWidth": tileWidth,
"tileHeight": tileHeight,
"value": value,
};
}
full code
import 'package:flutter/material.dart';
import 'dart:convert';
void main() => runApp(MyApp());
List<Game> gameFromJson(String str) =>
List<Game>.from(json.decode(str).map((x) => Game.fromJson(x)));
String gameToJson(List<Game> data) =>
json.encode(List<dynamic>.from(data.map((x) => x.toJson())));
class Game {
double x;
double y;
double tileWidth;
double tileHeight;
String value;
Game({
this.x,
this.y,
this.tileWidth,
this.tileHeight,
this.value,
});
factory Game.fromJson(Map<String, dynamic> json) => Game(
x: json["x"],
y: json["y"],
tileWidth: json["tileWidth"],
tileHeight: json["tileHeight"],
value: json["value"],
);
Map<String, dynamic> toJson() => {
"x": x,
"y": y,
"tileWidth": tileWidth,
"tileHeight": tileHeight,
"value": value,
};
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
// This is the theme of your application.
//
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or simply save your changes to "hot reload" in a Flutter IDE).
// Notice that the counter didn't reset back to zero; the application
// is not restarted.
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
static String data =
'[ {"x" : 1.0, "y" : 2.0, "tileWidth" : 100.0, "tileHeight" : 200.0, "value" : "test"}, {"x" : 10.0, "y" : 20.0, "tileWidth" : 100.0, "tileHeight" : 200.0, "value" : "test 2"} ] ';
List<Game> items = gameFromJson(data);
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
// This call to setState tells the Flutter framework that something has
// changed in this State, which causes it to rerun the build method below
// so that the display can reflect the updated values. If we changed
// _counter without calling setState(), then the build method would not be
// called again, and so nothing would appear to happen.
_counter++;
});
}
List<Widget> getList() {
List<Widget> widgeList = [];
for (var i = 0; i < 10; i++) {
for (var item in widget.items) {
widgeList.add(Positioned(
left: item.x,
bottom: item.y,
child: PhysicalModel(
borderRadius: BorderRadius.circular(10.0),
color: Colors.blueAccent,
child: Container(
width: item.tileWidth,
height: item.tileHeight,
child: Center(
child: Text(
item.value,
textAlign: TextAlign.center,
style: new TextStyle(
//fontSize: _myScreenWidth * 0.07,
//color: backgroundColor,
fontWeight: FontWeight.bold,
),
),
),
),
),
));
}
}
return widgeList;
}
#override
void initState() {
super.initState();
}
#override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: Stack(
children: getList(),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
demo, Widget 2 is on top of Widget 1