The class 'SimpleFoldingCell' doesn't have a default constructor - flutter

Question

https://github.com/flutter-devs/flutter_folding_cell_demo/blob/master/lib/demo_screen.dart
I'm trying to follow the code in the link above.
But in the SimpleFoldingCell part, an error named 'The class 'SimpleFoldingCell' doesn't have a default constructor.' occurs.
Could
Is there a way to resolve this error in Dart?
class Notific extends StatefulWidget{
#override
_State createState() => _State();
}
class _State extends State<Notific>{
late List<TechnologyModel> _technologyList;
#override
void initState() {
super.initState();
_technologyList = [
TechnologyModel(title: "Application Development",),
TechnologyModel(title: "Research & Development",),
TechnologyModel(title: "Big Data & Analytics",),
TechnologyModel(title: "Support Services",),
TechnologyModel(title: "QA & Software Testing",),
];
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
automaticallyImplyLeading: false,
backgroundColor: Colors.pink[200],
title: Text("Folding Cell Demo",
style: TextStyle(color: Colors.white),),
),
body: Container(
child: ListView.builder(
itemCount: _technologyList.length,
itemBuilder: (context, index) {
return SimpleFoldingCell(
frontWidget: _buildFrontWidget(index),
innerTopWidget: _buildInnerWidget(index),
innerBottomWidget: _buildInnerBottomWidget(),
cellSize: Size(MediaQuery.of(context).size.width, 125),
padding: EdgeInsets.all(15),
animationDuration: Duration(milliseconds: 200),
borderRadius: 10,
onOpen: () => print('$index cell opened'),
onClose: () => print('$index cell closed'),
);
},
),
),
);
}
Widget _buildFrontWidget(int index) {
return Builder(
builder: (BuildContext context) {
return Container(
color: Colors.cyan[100],
alignment: Alignment.bottomCenter,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
"Aeologic Technology",
style: TextStyle(
fontSize:20.0,
color: Colors.black,
),
),
SizedBox(height: 10,),
FlatButton(
onPressed: () {
final foldingCellState = context
.findAncestorStateOfType<SimpleFoldingCellState>();
foldingCellState?.toggleFold();
},
child: Text(
"OPEN",
),
textColor: Colors.white,
color: Colors.indigoAccent[100],
splashColor: Colors.white.withOpacity(0.5),
),
],
),
);
},
);
}
Widget _buildInnerBottomWidget() {
return Builder(
builder: (context) {
return Container(
color: Colors.blueGrey[50],
alignment: Alignment.bottomCenter,
child: Padding(
padding: EdgeInsets.only(bottom: 10),
child: FlatButton(
onPressed: () {
final foldingCellState = context
.findAncestorStateOfType<SimpleFoldingCellState>();
foldingCellState?.toggleFold();
},
child: Text(
"Close",
),
textColor: Colors.white,
color: Colors.redAccent[100],
splashColor: Colors.white.withOpacity(0.5),
),
),
);
}
);
}
Widget _buildInnerWidget(int index) {
return Builder(
builder: (context) {
return Container(
color: Colors.pink[100],
padding: EdgeInsets.only(top: 10),
child: Align(
alignment: Alignment.center,
child: Text(
_technologyList[index].title,
style: TextStyle(
fontSize:20.0,
color: Colors.black,
),
),
),
);
},
);
}
}
class TechnologyModel {
String title;
TechnologyModel({
required this.title,
});
}

Answer 1

For some reason they've created only a named constructor.
return SimpleFoldingCell.create(
frontWidget: _buildFrontWidget(index),
innerWidget: _buildInnerWidget(index),
// innerTopWidget: _buildInnerWidget(index),
// innerBottomWidget: _buildInnerBottomWidget(),
cellSize: Size(MediaQuery.of(context).size.width, 125),
padding: EdgeInsets.all(15),
animationDuration: Duration(milliseconds: 200),
borderRadius: 10,
onOpen: () => print('$index cell opened'),
onClose: () => print('$index cell closed'),
);
It looks like the demo you're looking at is a bit outdated, since some of those properties don't exist anymore (see commented code).