samples/web/charts/example/lib/combo_chart/scatter_plot_line.dart

// 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 combo scatter plot chart with a second series rendered as a
/// line.
// EXCLUDE_FROM_GALLERY_DOCS_START
import 'dart:math';
// EXCLUDE_FROM_GALLERY_DOCS_END
import 'package:charts_flutter/flutter.dart' as charts;
import 'package:flutter_web/material.dart';

class ScatterPlotComboLineChart extends StatelessWidget {
  final List<charts.Series> seriesList;
  final bool animate;

  ScatterPlotComboLineChart(this.seriesList, {this.animate});

  /// Creates a [ScatterPlotChart] with sample data and no transition.
  factory ScatterPlotComboLineChart.withSampleData() {
    return new ScatterPlotComboLineChart(
      _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 ScatterPlotComboLineChart.withRandomData() {
    return new ScatterPlotComboLineChart(_createRandomData());
  }

  /// Create random data.
  static List<charts.Series<LinearSales, num>> _createRandomData() {
    final random = new Random();

    final makeRadius = (int value) => (random.nextInt(value) + 2).toDouble();

    final desktopSalesData = [
      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
    ];

    var myRegressionData = [
      new LinearSales(0, desktopSalesData[0].sales, 3.5),
      new LinearSales(
          100, desktopSalesData[desktopSalesData.length - 1].sales, 7.5),
    ];

    final maxMeasure = 100;

    return [
      new charts.Series<LinearSales, int>(
        id: 'Sales',
        // Providing a color function is optional.
        colorFn: (LinearSales sales, _) {
          // Bucket the measure column value into 3 distinct colors.
          final bucket = sales.sales / maxMeasure;

          if (bucket < 1 / 3) {
            return charts.MaterialPalette.blue.shadeDefault;
          } else if (bucket < 2 / 3) {
            return charts.MaterialPalette.red.shadeDefault;
          } else {
            return charts.MaterialPalette.green.shadeDefault;
          }
        },
        domainFn: (LinearSales sales, _) => sales.year,
        measureFn: (LinearSales sales, _) => sales.sales,
        // Providing a radius function is optional.
        radiusPxFn: (LinearSales sales, _) => sales.radius,
        data: desktopSalesData,
      ),
      new charts.Series<LinearSales, int>(
          id: 'Mobile',
          colorFn: (_, __) => charts.MaterialPalette.purple.shadeDefault,
          domainFn: (LinearSales sales, _) => sales.year,
          measureFn: (LinearSales sales, _) => sales.sales,
          data: myRegressionData)
        // Configure our custom line renderer for this series.
        ..setAttribute(charts.rendererIdKey, 'customLine'),
    ];
  }
  // EXCLUDE_FROM_GALLERY_DOCS_END

  @override
  Widget build(BuildContext context) {
    return new charts.ScatterPlotChart(seriesList,
        animate: animate,
        // Configure the default renderer as a point renderer. This will be used
        // for any series that does not define a rendererIdKey.
        //
        // This is the default configuration, but is shown here for
        // illustration.
        defaultRenderer: new charts.PointRendererConfig(),
        // Custom renderer configuration for the line series.
        customSeriesRenderers: [
          new charts.LineRendererConfig(
              // ID used to link series to this renderer.
              customRendererId: 'customLine',
              // Configure the regression line to be painted above the points.
              //
              // By default, series drawn by the point renderer are painted on
              // top of those drawn by a line renderer.
              layoutPaintOrder: charts.LayoutViewPaintOrder.point + 1)
        ]);
  }

  /// Create one series with sample hard coded data.
  static List<charts.Series<LinearSales, int>> _createSampleData() {
    final desktopSalesData = [
      new LinearSales(0, 5, 3.0),
      new LinearSales(10, 25, 5.0),
      new LinearSales(12, 75, 4.0),
      new LinearSales(13, 225, 5.0),
      new LinearSales(16, 50, 4.0),
      new LinearSales(24, 75, 3.0),
      new LinearSales(25, 100, 3.0),
      new LinearSales(34, 150, 5.0),
      new LinearSales(37, 10, 4.5),
      new LinearSales(45, 300, 8.0),
      new LinearSales(52, 15, 4.0),
      new LinearSales(56, 200, 7.0),
    ];

    var myRegressionData = [
      new LinearSales(0, 5, 3.5),
      new LinearSales(56, 240, 3.5),
    ];

    final maxMeasure = 300;

    return [
      new charts.Series<LinearSales, int>(
        id: 'Sales',
        // Providing a color function is optional.
        colorFn: (LinearSales sales, _) {
          // Bucket the measure column value into 3 distinct colors.
          final bucket = sales.sales / maxMeasure;

          if (bucket < 1 / 3) {
            return charts.MaterialPalette.blue.shadeDefault;
          } else if (bucket < 2 / 3) {
            return charts.MaterialPalette.red.shadeDefault;
          } else {
            return charts.MaterialPalette.green.shadeDefault;
          }
        },
        domainFn: (LinearSales sales, _) => sales.year,
        measureFn: (LinearSales sales, _) => sales.sales,
        // Providing a radius function is optional.
        radiusPxFn: (LinearSales sales, _) => sales.radius,
        data: desktopSalesData,
      ),
      new charts.Series<LinearSales, int>(
          id: 'Mobile',
          colorFn: (_, __) => charts.MaterialPalette.purple.shadeDefault,
          domainFn: (LinearSales sales, _) => sales.year,
          measureFn: (LinearSales sales, _) => sales.sales,
          data: myRegressionData)
        // Configure our custom line renderer for this series.
        ..setAttribute(charts.rendererIdKey, 'customLine'),
    ];
  }
}

/// Sample linear data type.
class LinearSales {
  final int year;
  final int sales;
  final double radius;

  LinearSales(this.year, this.sales, this.radius);
}