samples/web/charts/example/lib/behaviors/percent_of_series.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 percentage bar chart which shows each bar as the percentage of
/// the total series measure value.
// EXCLUDE_FROM_GALLERY_DOCS_START
import 'dart:math';
// EXCLUDE_FROM_GALLERY_DOCS_END
import 'package:flutter_web/material.dart';
import 'package:charts_flutter/flutter.dart' as charts;

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

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

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

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

    final desktopSalesData = [
      new OrdinalSales('2014', random.nextInt(100)),
      new OrdinalSales('2015', random.nextInt(100)),
      new OrdinalSales('2016', random.nextInt(100)),
      new OrdinalSales('2017', random.nextInt(100)),
      new OrdinalSales('2014', random.nextInt(100)),
      new OrdinalSales('2015', random.nextInt(100)),
      new OrdinalSales('2016', random.nextInt(100)),
      new OrdinalSales('2017', random.nextInt(100)),
    ];

    return [
      new charts.Series<OrdinalSales, String>(
        id: 'Desktop',
        domainFn: (OrdinalSales sales, _) => sales.year,
        measureFn: (OrdinalSales sales, _) => sales.sales,
        data: desktopSalesData,
      ),
    ];
  }
  // EXCLUDE_FROM_GALLERY_DOCS_END

  @override
  Widget build(BuildContext context) {
    return new charts.BarChart(
      seriesList,
      animate: animate,
      barGroupingType: charts.BarGroupingType.grouped,
      // Configures a [PercentInjector] behavior that will calculate measure
      // values as the percentage of the total of all data in its series.
      behaviors: [
        new charts.PercentInjector(
            totalType: charts.PercentInjectorTotalType.series)
      ],
      // Configure the axis spec to show percentage values.
      primaryMeasureAxis: new charts.PercentAxisSpec(),
    );
  }

  /// Create series list with multiple series
  static List<charts.Series<OrdinalSales, String>> _createSampleData() {
    final desktopSalesData = [
      new OrdinalSales('2011', 5),
      new OrdinalSales('2012', 25),
      new OrdinalSales('2013', 50),
      new OrdinalSales('2014', 75),
      new OrdinalSales('2015', 100),
      new OrdinalSales('2016', 125),
      new OrdinalSales('2017', 200),
      new OrdinalSales('2018', 150),
    ];

    return [
      new charts.Series<OrdinalSales, String>(
        id: 'Desktop',
        domainFn: (OrdinalSales sales, _) => sales.year,
        measureFn: (OrdinalSales sales, _) => sales.sales,
        data: desktopSalesData,
      ),
    ];
  }
}

/// Sample ordinal data type.
class OrdinalSales {
  final String year;
  final int sales;

  OrdinalSales(this.year, this.sales);
}