// Copyright 2018 the Charts project authors. Please see the AUTHORS file // for details. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. /// Example of a line chart with null measure values. /// /// Null values will be visible as gaps in lines and area skirts. Any data /// points that exist between two nulls in a line will be rendered as an /// isolated point, as seen in the green series. // EXCLUDE_FROM_GALLERY_DOCS_START import 'dart:math'; // EXCLUDE_FROM_GALLERY_DOCS_END import 'package:charts_flutter/flutter.dart' as charts; import 'package:flutter/material.dart'; class SimpleNullsLineChart extends StatelessWidget { final List> seriesList; final bool? animate; const SimpleNullsLineChart(this.seriesList, {this.animate, Key? key}) : super(key: key); /// Creates a [LineChart] with sample data and no transition. factory SimpleNullsLineChart.withSampleData() { return SimpleNullsLineChart( _createSampleData(), // Disable animations for image tests. animate: false, ); } // EXCLUDE_FROM_GALLERY_DOCS_START // This section is excluded from being copied to the gallery. // It is used for creating random series data to demonstrate animation in // the example app only. factory SimpleNullsLineChart.withRandomData() { return SimpleNullsLineChart(_createRandomData()); } /// Create random data. static List> _createRandomData() { final random = Random(); final myFakeDesktopData = [ LinearSales(0, random.nextInt(100)), LinearSales(1, random.nextInt(100)), LinearSales(2, null), LinearSales(3, random.nextInt(100)), LinearSales(4, random.nextInt(100)), LinearSales(5, random.nextInt(100)), LinearSales(6, random.nextInt(100)), ]; var myFakeTabletData = [ LinearSales(0, random.nextInt(100)), LinearSales(1, random.nextInt(100)), LinearSales(2, random.nextInt(100)), LinearSales(3, random.nextInt(100)), LinearSales(4, random.nextInt(100)), LinearSales(5, random.nextInt(100)), LinearSales(6, random.nextInt(100)), ]; var myFakeMobileData = [ LinearSales(0, random.nextInt(100)), LinearSales(1, random.nextInt(100)), LinearSales(2, null), LinearSales(3, random.nextInt(100)), LinearSales(4, null), LinearSales(5, random.nextInt(100)), LinearSales(6, random.nextInt(100)), ]; return [ charts.Series( id: 'Desktop', colorFn: (_, __) => charts.MaterialPalette.blue.shadeDefault, domainFn: (LinearSales sales, _) => sales.year, measureFn: (LinearSales sales, _) => sales.sales, data: myFakeDesktopData, ), charts.Series( id: 'Tablet', colorFn: (_, __) => charts.MaterialPalette.red.shadeDefault, domainFn: (LinearSales sales, _) => sales.year, measureFn: (LinearSales sales, _) => sales.sales, data: myFakeTabletData, ), charts.Series( id: 'Mobile', colorFn: (_, __) => charts.MaterialPalette.green.shadeDefault, domainFn: (LinearSales sales, _) => sales.year, measureFn: (LinearSales sales, _) => sales.sales, data: myFakeMobileData, ), ]; } // EXCLUDE_FROM_GALLERY_DOCS_END @override Widget build(BuildContext context) { return charts.LineChart(seriesList, animate: animate); } /// Create one series with sample hard coded data. static List> _createSampleData() { final myFakeDesktopData = [ LinearSales(0, 5), LinearSales(1, 15), LinearSales(2, null), LinearSales(3, 75), LinearSales(4, 100), LinearSales(5, 90), LinearSales(6, 75), ]; final myFakeTabletData = [ LinearSales(0, 10), LinearSales(1, 30), LinearSales(2, 50), LinearSales(3, 150), LinearSales(4, 200), LinearSales(5, 180), LinearSales(6, 150), ]; final myFakeMobileData = [ LinearSales(0, 15), LinearSales(1, 45), LinearSales(2, null), LinearSales(3, 225), LinearSales(4, null), LinearSales(5, 270), LinearSales(6, 225), ]; return [ charts.Series( id: 'Desktop', colorFn: (_, __) => charts.MaterialPalette.blue.shadeDefault, domainFn: (LinearSales sales, _) => sales.year, measureFn: (LinearSales sales, _) => sales.sales, data: myFakeDesktopData, ), charts.Series( id: 'Tablet', colorFn: (_, __) => charts.MaterialPalette.red.shadeDefault, domainFn: (LinearSales sales, _) => sales.year, measureFn: (LinearSales sales, _) => sales.sales, data: myFakeTabletData, ), charts.Series( id: 'Mobile', colorFn: (_, __) => charts.MaterialPalette.green.shadeDefault, domainFn: (LinearSales sales, _) => sales.year, measureFn: (LinearSales sales, _) => sales.sales, data: myFakeMobileData, ), ]; } } /// Sample linear data type. class LinearSales { final int year; final int? sales; LinearSales(this.year, this.sales); }