main.dart

import 'package:example/radar_chart/radar_chart_page.dart';
import 'package:example/scatter_chart/scatter_chart_page.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:fl_chart/fl_chart.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'FlChart Demo',
      showPerformanceOverlay: false,
      theme: ThemeData(
        primaryColor: const Color(0xff262545),
        primaryColorDark: const Color(0xff201f39),
        brightness: Brightness.dark,
      ),
      home: Scaffold(
        backgroundColor: Colors.white,
        body: Center(
          child: SizedBox(
            width: 300,
            height: 150,
            child: MyCustomizedChart(),
          ),
        ),
      ),
    );
  }
}

class MyCustomizedChart extends StatefulWidget {
  @override
  _MyCustomizedChartState createState() => _MyCustomizedChartState();
}

class _MyCustomizedChartState extends State<MyCustomizedChart> {
  final Color lineDefaultColor = Colors.green.withOpacity(0.4);
  final Color lineTouchedColor = Colors.green;

  Color currentColor;

  @override
  void initState() {
    super.initState();
    currentColor = lineDefaultColor;
  }

  @override
  Widget build(BuildContext context) {
    return LineChart(
      LineChartData(
          lineBarsData: [
            LineChartBarData(
              colors: [currentColor],
              spots: [
                FlSpot(0, 0),
                FlSpot(1, 1),
                FlSpot(2, 1.5),
                FlSpot(3, 1),
                FlSpot(4, 2),
                FlSpot(5, 1),
              ],
            )
          ],
          lineTouchData: LineTouchData(touchCallback: (LineTouchResponse response) {
            setState(() {
              if (response.touchInput is FlPanStart ||
                  response.touchInput is FlPanMoveUpdate ||
                  response.touchInput is FlLongPressStart ||
                  response.touchInput is FlLongPressMoveUpdate) {
                currentColor = lineTouchedColor;
              } else {
                currentColor = lineDefaultColor;
              }
            });
          })),
    );
  }
}