passing data from TextFormField into a list in flutter

Question

1- I am working on a code that creates a graph and produces a relationship between two variables. 2- But I can't store the data in a list from TextEditingController

class _HomePageState extends State<HomePage> {
  // final firstnameController = TextEditingController();
  TextEditingController value1 =TextEditingController();
  TextEditingController  value2 =TextEditingController();

  List<Acceleration> data = [
    Acceleration('1', value1  ),
    Acceleration('2', value2),
    Acceleration('3', 40),
    Acceleration('4', 30),
    Acceleration('5', 20),
    Acceleration('june', 33),
    Acceleration('july', 22),
  ];
 

 @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Line Chart speadTimeRelation"),
        centerTitle: true,
        backgroundColor: Colors.green[700],
        // brightness: Brightness.dark,
      ),
      body: GetBuilder<HomeControler>(
        init: HomeControler(),
        builder: (controller) {
          return Column(
            children: [
              TextFormField(
                controller: value1,
              ),


              Container(
                padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 20),
                child: SfCartesianChart(
                  primaryXAxis:const CategoryAxis(),
                  title:const ChartTitle(text: 'speadTimeRelation Analysis'),
                  legend: const Legend(isVisible: true,),
                  tooltipBehavior: TooltipBehavior(enable: true),
                  series: <LineSeries<Acceleration, String>>[
                    LineSeries<Acceleration, String>(
                      dataSource: data,
                      xValueMapper: (Acceleration speadTimeRelation, _) => speadTimeRelation.time,
                      yValueMapper: (Acceleration speadTimeRelation, _) => speadTimeRelation.spead,
                      name: 'speadTimeRelation',
                      dataLabelSettings: const DataLabelSettings(isVisible: true),
                    ),
                  ],
                ),
              ),
            ],
          );
        }
      ),
    );
  }
}


class Acceleration{

  final String time;
  final double spead;

  Acceleration(this.time, this.spead);

}

Answer 1

 class _HomePageState extends State<HomePage> {
  // final firstnameController = TextEditingController();
  TextEditingController value1 = TextEditingController();
  TextEditingController value2 = TextEditingController();

  List<Acceleration> data = [
    Acceleration('1', 50), // for first initialize
    Acceleration('2', 50), // for first initialize
    Acceleration('3', 40),
    Acceleration('4', 30),
    Acceleration('5', 20),
    Acceleration('june', 33),
    Acceleration('july', 22),
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Line Chart speadTimeRelation"),
        centerTitle: true,
        backgroundColor: Colors.green[700],
        // brightness: Brightness.dark,
      ),
      body: GetBuilder<HomeControler>(
          init: HomeControler(),
          builder: (controller) {
            return Column(
              children: [
                TextField(                                // use TextField then TextFormField, because you don't use a form
                  controller: value1,
                  onChanged: (valueFromController1) {
                    setState(() {                         // setState to rebuild the widget and update the chart
                      data[0] = Acceleration('1', double.tryParse(valueFromController1)!);
                    });
                  },
                ),
                const SizedBox(height: 8),
                TextField(
                  controller: value2,
                  onChanged: (valueFromController2) {
                    setState(() {
                      data[1] = Acceleration('2', double.tryParse(valueFromController2)!);
                    });
                  },
                ),
                const SizedBox(height: 8),
                Container(
                  padding:
                      const EdgeInsets.symmetric(horizontal: 10, vertical: 20),
                  child: SfCartesianChart(
                    primaryXAxis: const CategoryAxis(),
                    title: const ChartTitle(text: 'speadTimeRelation Analysis'),
                    legend: const Legend(
                      isVisible: true,
                    ),
                    tooltipBehavior: TooltipBehavior(enable: true),
                    series: <LineSeries<Acceleration, String>>[
                      LineSeries<Acceleration, String>(
                        dataSource: data,
                        xValueMapper: (Acceleration speadTimeRelation, _) =>
                            speadTimeRelation.time,
                        yValueMapper: (Acceleration speadTimeRelation, _) =>
                            speadTimeRelation.spead,
                        name: 'speadTimeRelation',
                        dataLabelSettings:
                            const DataLabelSettings(isVisible: true),
                      ),
                    ],
                  ),
                ),
              ],
            );
          }),
    );
  }
}

class Acceleration {
  final String time;
  final double spead;

  Acceleration(this.time, this.spead);
}