Custom filtered data points

main.dart

import 'dart:ui';

import 'package:fl_chart/fl_chart.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';

final rawData = [
  {
    'week_day': 'Sat',
    'date': '2022-02-01',
    'value': 11,
  },
  {
    'week_day': 'Sun',
    'date': '2022-02-02',
    'value': 15,
  },
  {
    'week_day': 'Mon',
    'date': '2022-02-03',
    'value': 13,
  },
  {
    'week_day': 'Tue',
    'date': '2022-02-04',
    'value': 16,
  },
  {
    'week_day': 'Wed',
    'date': '2022-02-05',
    'value': 14,
  },
  {
    'week_day': 'Thu',
    'date': '2022-02-06',
    'value': 15,
  },
  {
    'week_day': 'Fri',
    'date': '2022-02-07',
    'value': 18,
  },
  {
    'week_day': 'Sat',
    'date': '2022-02-08',
    'value': 16,
  },
  {
    'week_day': 'Sun',
    'date': '2022-02-09',
    'value': 19,
  },
  {
    'week_day': 'Mon',
    'date': '2022-02-10',
    'value': 17,
  },
  {
    'week_day': 'Tue',
    'date': '2022-02-11',
    'value': 15,
  },
  {
    'week_day': 'Wen',
    'date': '2022-02-12',
    'value': 8,
  },
  {
    'week_day': 'Thu',
    'date': '2022-02-13',
    'value': 16,
  },
  {
    'week_day': 'Sat',
    'date': '2022-02-14',
    'value': 18,
  },
  {
    'week_day': 'Sun',
    'date': '2022-02-15',
    'value': 19,
  },
  {
    'week_day': 'Mon',
    'date': '2022-02-16',
    'value': 14,
  }
];

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final dataPoints = rawData.map((e) => RawDataPoint(e)).toList();
    final skippedWeekends = dataPoints.where((dataPoint) => dataPoint.isNotWeekend).toList();

    return MaterialApp(
      title: 'FlChart Demo',
      showPerformanceOverlay: false,
      home: MyHomePage(showingPoints: skippedWeekends),
    );
  }
}

class RawDataPoint {
  final String weekDay;
  final String date;
  final int value;

  RawDataPoint(Map<String, dynamic> json)
      : weekDay = json['week_day'],
        date = json['date'],
        value = json['value'];

  bool get isWeekend => weekDay == 'Sat' || weekDay == 'Sun';

  bool get isNotWeekend => !isWeekend;
}

class MyHomePage extends StatefulWidget {
  final List<RawDataPoint> showingPoints;

  MyHomePage({Key? key, required this.showingPoints}) : super(key: key);

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    var flSpots = widget.showingPoints.asMap().entries.map((e) {
      final index = e.key;
      final dataPoint = e.value;
      return FlSpot(index.toDouble(), dataPoint.value.toDouble());
    }).toList();

    return Scaffold(
      body: SafeArea(
        child: Center(
          child: AspectRatio(
            aspectRatio: 1.8,
            child: Container(
              margin: const EdgeInsets.only(right: 42.0, left: 28),
              child: LineChart(
                LineChartData(
                  lineBarsData: [
                    LineChartBarData(
                      spots: flSpots,
                    ),
                  ],
                  minY: 4,
                  maxY: 20,
                  titlesData: FlTitlesData(
                      show: true,
                      leftTitles: SideTitles(
                        showTitles: true,
                        checkToShowTitle: (minValue, maxValue, sideTitles, appliedInterval, value) => value % 2 == 0,
                      ),
                      bottomTitles: SideTitles(
                        showTitles: true,
                        getTitles: (value) {
                          final dataPoint = widget.showingPoints[value.toInt()];
                          return '${dataPoint.date}';
                        },
                        rotateAngle: -35,
                        getTextStyles: (context, value) => TextStyle(fontSize: 10),
                      )),
                  gridData: FlGridData(
                    show: false,
                  ),
                  lineTouchData: LineTouchData(
                    enabled: true,
                    touchTooltipData: LineTouchTooltipData(
                      getTooltipItems: (List<LineBarSpot> touchedSpots) {
                        return touchedSpots.map((lineBarSpot) {
                          final dataSpot = widget.showingPoints[lineBarSpot.spotIndex];

                          return LineTooltipItem(dataSpot.value.toString(), TextStyle(color: Colors.white), children: [
                            TextSpan(
                              text: '\n${dataSpot.weekDay}',
                              style: TextStyle(
                                color: Colors.white,
                                fontWeight: FontWeight.bold,
                              ),
                            )
                          ]);
                        }).toList();
                      },
                    ),
                  ),
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}

custom_filtered_data_points.mp4